Mule Deer Decline in the West a Symposium

MULE DEER DECLINE IN THE WEST A SYMPOSIUM

utah state university college of natural resources utah agricultural experiment station logan, utah 84322 MULE DEER DECLINE IN THE WEST

A SYMPOSIUM

Editors and Symposium Directors:

Gar N. Workman Jessop B. Low

Sponsored by :

College of Natural Resources, Utah State University Natural Resources Alumni Association, Utah State University Extension Services, Utah State University Utah Chapter of The Wildlife Society Bonneville Chapter of the American Fisheries Society Intermountain Section of the Society of American Foresters Utah Chapter of the Soil Conservation Society of America ACKNOWLEDGMENTS

The session chairmen for this symposium were: Norman V. Hancock, Chief4ame Management, Utah Division of Wildlife Resources; Paul W. Shields, Utah Regional Wildlife Biologist, U. S. Forest Service; Ronald S. Trogstad, Utah Wildlife Management Biologist, Bureau of Land Management.

The following secretaries also assisted in preparation of the program, typing, and providing assistance to speakers and guests: Karen Mitchell, Lonna Beth Bowles, and Marcie Egbert . FOREWORD

Mule deer numbers in the Western United States This symposium was designed to help natural re- experienced a general decline in nmbers from the source managers become better informed about the early 1950's until the present mid-1970's. At least reduction and the various reasons for the mule deer a part of this decline was a result of a planned re- decline in the West. The speakers at this confer- duction by game managers to adjust deer numbers to ence are considered to be authorities on the various the carrying capacity of overused deer winter ranges. aspects of mule deer populations. Subsequently, the In addition to the planned reduction of deer numbers, information presented in these proceedings represents it became apparent by 1970 that the reduction in nun- some of the important current knowledge pertaining ber of deer on western ranges was the result of some- to present-day mule deer populations, research, and thing beyond the planned reduction programs. The management. cause, or causes, for the reduction was not clearly understood or even defined in many cases. Such influences as predation, canpetition, weather, disease, habitat changes, and nutrition were suspected causes. Gar W. Workman and Jessop B. Low Perhaps the main cause of the decline has not been discussed and will need to wait for further research. Table of Contents

Page Acknowledgments ...... Foreword ...... Introduction to Conference ...... A Historical Account and Present Status of the Mule Deer in the West ...... Mule Deer Habitat Changes Resulting from Livestock Practices ...... Alteration of Mule Deer Habitat by Wildfire. Logging. Highways. Agriculture. and HousingDevelopments ...... Interspecific Competition Between Mule Deer. Other Game Animals. and Livestock ...... Deer Range Improvement and Mule Deer Management ...... An Overview of Big Game Management ...... Mule Deer Nutrition and Plant Utilization ...... Mule Deer Productivity.. Past and Present ...... Regulations and the Mule Deer Harvest.. Political and Biological Management ......

Reliability of Mule Deer Population Measurements ...... a

Mule Deer Management Myths and the Mule Deer Population Decline ...... a. The Possible Influences of the Mountain Lion on Mule Deer Populations ...... Potential Influence of Coyotes on Mule Deer Populations ...... Mule Deer Disease Problems ...... Mule Deer Mortality from Various Causes ...... Probable Causes of the Recent Decline of Mule Deer in the Western U.S...A StmmarY ...... INTRODUCTION TO CONFERENCE

John E. Phelps, Director Utah Division of Wildlife Resources

Since pioneer days, the Western mule deer has 5) The exceptionally long, cold spring been of great value and concern to the populace. of 1975 extended into June and caused signi- Earlier settlers were alarmed about scarcity of the ficant fawn losses during the peak of the animals. At the turn of the century, grandfather and fawn drop in southern and south-central Utah. father talked for days about the event if by chance they saw a deer. 6) Another cause is the predator. Principal predators are dogs (domestic and Things changed, however, and populations of feral), coyotes, and mountain lions. deer increased. In the late 1940's and early 1950's landowners and livestock people complained bitterly 7) Other general factors are operating about deer on their land or on federal lands. At that also. These are highway mortality, disease, time, game managers recognized the need for reduc- accidents, and poaching. Undoubtedly, tion of the size of deer herds. A program to reduce there are other things involved which at this deer populations was generally carried on until the time we do not understand. middle 1960's. However, hunters generally felt that the game departments were going too far. Unfortun- 8) Finally, there is another concern ately, we failed to persuade many people this was which in importance would be well up on a calculated management plan, and as a result, many this list, but, for the sake of treatment only, vocal critics emerged. I have reserved for the last. This is habitat loss. This loss is a slow, creeping activity In my opinion, since the early 1970's there has which sometimes is so gradual that we do not been a general decline in the population of the West- recognize it until we begin to see its ern mule deer. combined cumulative effects.

Big game technicians in the Western Association Chief habitat losses that we see are caused of State Game and Fish Commissioners held two meet- by urbanization, land speculation, the second-home ings, one in 1964 and the other in 1968, to discuss movement, and adverse plant succession away from the general decline of some of the desert herds in the browse species. This latter has been intensified Southwest. by the total elimination of livestock grazing on many deer winter ranges. The philosophical basis for In 1970, an annual western mule deer workshop eliminating livestock grazing emerged from a point was inaugurated because of a decline or fluctuation of view that management of the watershed should be in most mule deer herds throughout the West. During carried out with the ultimate goal of establishing the first few workshops, emphasis was on productiv- and maintaining a climax vegetation of grasses. ity and fawn survival. Technicians now recognize that there is probably no single factor to which a de- Prior to the smokey-the-e ear syndrome and cline can be attributed. modern fire fighting techniques, nature and the Indian provided for a diversification of a climax Erratic fawn production occurred in the desert vegetation by fire. Until very recent times, our herds of the West in the late 1960's. It was the early colonization further extended several vegetative 1970's when more significant, widespread, and abrupt stages through widespread use of domestic live- drops in fawn production occurred throughout most of stock. Unfortunately, now there is developing an the Western States. General causes for the decline antagonistic attitude towards livestock grazing on in Utah were noted. Undoubtedly, most of these public lands. factors were operative in other Western States. It is necessary to have this grazing as a le- Following are some of the causes of the decline gitimate range management tool to maintain vege- in Utah deer herd numbers. They are arranged in tative types for multiple uses. We should be think- order of their importance. ing of it in terms of proper livestock grazing and correct season of use. 1) The winter loss of 1972-1973. This is the principal factor for a statewide decline in Utah. In the course of the next day and a half, we are going to have the opportunity of exploring some 2) Does were in poor shape in the spring of these factors and undoubtedly others. By tomor- of 1973 following this bad winter. As a result, row afternoon, I hope we are able to see where they fawn production was down. This varied con- fit into the overall status of our past and present siderably from unit to unit. mule deer herds throughout the West.

3) In the eastern and south-central parts For the peace of mind of the directors of the of the state, 1972 fawn crops were down as a wildlife agencies of the Western States, an result of drought conditions in 1971-1972. optimistic future is predicated--we are going to look at the future, not just the past and present. 4) High antlerless removal occurred in the central and south-central parts of Utah during 1971, 1972, 1973, and 1974.

1 Introduction to Conference A HISTORICAL ACCOUNT AND PRESENT STATUS

OF Tm MULE DEER IN THE WEST

Ode11 Julander Professor Emeritus Brigham Young University, Provo, Utah 84601

Jessop B. Low Professor Department of Wildlife Science Utah State University, Logan, Utah 84322

Abstract

The decline of mule deer (Odocoileus hemionus) has been documented by most western states during the past several years. In the main, the decline has been attributed to a number of causes, principally, however, to overhagvesting, range reduction, habitat change from livestock and deer pressure, poor deer reproduction, urbanization, fire control, and management efforts to reduce herds nearer range carrying capacity. The history of the mule deer herds noted scarcity during prepioneer days and the early pioneer settlement period to a large buildup of herds during the second quarter of the twentieth century. The buildup was Concurrent with conversion of ranges from grass to browse, control of pre- datators and protection of herds through limited and manipulated harvests. Large herds in the late 1930s through the 1960s were reduced through control permits above the regular harvest. Documented data on a number of individual herds in Utah and Arizona indicate a general decline in numbers as a result of management to bring deer numbers within carrying capacity of the range.

The decline of the mule deer in the West has been even more states were documenting the de- of major concern to most state conservation agencies cline (Russo, 1968) -Arizona; (Macgregor , during recent years. Many states have documented this 1968)-Nevada; (Nielson and Williams, 1968)- decline in population and harvest trends, as well as Idaho; (Snyder, 1968)-New Mexico; (Stein, hunter success. Following periods of relatively few 1968)-0regon; (Lauchart, 1968)-Washington; deer in prepioneer days, then depletion of the pop- (Corsi, 1968)-Wyoming; and (Hancock, 1968)- ulations by the early pioneers and the increasing num- Utah. bers in the first half of the century, the herds have now decreased and appear to be declining even further. Many people have blamed the decline to overshooting, predators, range reduction or deterioration The declining populations of mule deer was rec- from too many livestock, and the presence of too many ognized and documented by many workers, as pointed deer, which literally "ate themselves out of house out by Longhurst et al. (1976): and home." Urbanization, fire control, and the causes and reasons are legend, depending upon who For that matter, the decline of deer asks and answers the question--sportsman, biologist, has by no means been confined to California, administrator, or housewife. Perhaps our question but seems to have been a general phenomenon should not be, "Has there been an unexplained de- in a number of western states. By 1964 a cline?", but rather, "Has the decline or reduction number of states recognized that Rocky been the response of deliberate programs designed to Mountain mule deer populations had started manage watersheds or reduce over populations of deer to decline (Macgregor, 1964)-California; that had previously responded to favorable manage- (Mohler, 1964)-Idaho; (McKean and Luman, ment practices or favorable habitat conditions and 1964)-Oregon; (Greenly and Humphreys, 1964)- thus built up beyond the normal carrying capacity of Nevada; and (Hancock, 1964)-Utah. By 1968 their ranges?"

3 A HistoricaZ Accomt and Present Status of the Mule Deers in the West We acknowledge the fine response from all fish hides were even used as legal tender (50~ and game organizations in the western states regarding per hide) in parts of Montana just before the history of mule deer in their state. We must, the turn of the century. of course, in the interest of time, paint with a broad brush the history and present status of mule deer in Lewis and Clark can be credited with the West. To do otherwise would entail too much space writing the first detailed account of mule and time. Since we are most acquainted with Utah, our deer habitat requirements. There is evidence emphasis will undoubtedly be on the history of the that Lewis coined the name, "Mule Deer," when deer in this state. However, the same general picture he stated, "We have rarely found the mule prevails in most western states. deer in any except rough country. They prefer the oDen grounds and are seldom found in woodlands or river bottom." (Egan, 1971)

Relative Nunbers Prior to Early Pioneer Days Practically all states with mule deer have records, diaries, and histories pointing out the Relatively little is known concerning the true scarcity of deer in the early prepioneer days, but numbers of mule deer prior to the early pioneers. indicating that deer were known to occur in about all Trappers and early explorers rarely reported deer, the states now having mule deer. Deer was not the except incident to other observations. choice food of the beaver trappers or explorers, who chose bighorn sheep and elk when possible. Deer Father Escalante's party in September and October, was, however, taken when possible as food by ex- 1776, explored the Utah area and other western terri- plorers and trappers alike. The Lewis and Clark ex- tories. Although Escalante traveled through and along pedition of the early 1800's detailed the wildlife, the borders of some of Utah's best present-day big including deer, in the northwest. Such trappers and game hunting grounds, he made no mention of either deer explorers as Peter Skene Ogden, Townsend, and or elk, both of which he noted in southwestern Colo- Alexander Ross also recorded in their journals about rado. Further, Escalante reported that while travel- the relative scarcity of deer in comparison to other ing south from Utah Lake the party ran out of food and wildlife. experienced great difficulty in obtaining grain, seeds and nuts from the Indians and found it necessary to kill several of their horses for food. In other areas they reportedly kill.ed buffalo, traded with Indians Depletion of Mule Deer in Pioneer Days for bighorn sheep meat, but made no mention of deer. When the pioneers entered the Great Salt Lake In the 1820-1834 period of exploration and in- Valley on July 24, 1847, big game animals were scarce, tensive fur trapping, stalwart mountain men, such as as reported bv the trappers and explorers. The hearty J.S. Smith, 1826-1827; W.A. Ferris, 1830-1834; J.R. pioneers suffered acute food shortages during the Walker, 1833-1834; and others, recorded in diaries and first winter. Indians and whites alike vigorously journals only indicental mule deer, although buffalo, hunted the few deer for their meat and hides. antelope, elk, and beaver were regularly recorded. Captain Stansbury reported that during the Osborn Russell recorded mule deer in his diary winter and spring of 1847-1848, Mormon pioneers in during the period 1834-1843, while trapping beaver in the Great Salt Lake Valley were forced to dig roots northern Utah in 1837, he speaks of having a Christmas and tear hides from their roofs in order to survive. party with his family and friends in which "The next He frequently mentioned that game was scarce this dish was similar to the first (elk) heaped up with first winter in the valley. Thus, although we have boiled deer meat (or as the whites call it, venison, no historical record upon which numerical estimates a term not used in the mountains.)" (Haines, 1955, of deer numbers in ZTtah can be based at the time of p. 115). Later, in what was probably Utah County, he the first settlements, it is apparent that there speaks of the Indians: "If a Eutaw has 8 or 10 good were relatively few deer. horses, a rifle, and ammunition, he is contented if he fetches a deer at night from the hunt. . ." (Haines, During the period between the advent of the 1955, p. 121). pioneers and the end of the century, severe depletion of Utah's grasslands occurred as a result of excess- Essentially the same story is told in all western ive grazing by domestic livestock gave rise to the states in prepioneer days--that of relatively few spread and abundance of browse species, many of which deer, apparently in harmony with their environment were choice deer foods, which set the stage for the and habitat. Montana records that: deer population booms to come not too many years later. The unrestricted hunting and unrestricted Mule deer (Odocoileus hemoinus) have grazing by domestic stock over the entire state had, been an important big game animal in Montana by the turn of the century, depleted much of the as far back as records exist. The popularity native forage and big game numbers to the extent that of this native deer among the Indians might action was necessary to save both of these resources be ascribed to the fact the meat, fresh or (Utah Biennial Report, 1946). cured, is very palatable; the hide was used to make buckskin, and even the bones and One old timer that I interviewed about 1950 re- antlers made useful implements. calls that in about 1900, he, as a youth living near the hills directly above Providence in Cache Valley, The early explorers, fur trappers, and Utah, found deer tracks scarce. On one occasion, he settlers also used and depended on the mule reportedly followed a deer track for four consecutive deer as a source of food and clothing. The

A Historical Accomt and Present Status of the 4 Mule Deer in the West days before getting a fleeting glimpse of the animal New Xexico (Low, personal files). In 1880, the first conservation law was passed in New Mexico because of The significant events and conditions affecting the continued decline in game numbers. . . Utah's mule deer populations from early historic times Two years later, in 1899, a bag limit of one to the present are briefly given in Table 1 and fur- buck deer was imposed by the Territorial ther illustrated in Figure l. Legislature. Because the public refused to accept the law, decimation of game continued; therefore, the territorial law- makers placed a five-year closure on the Other States hunting of deer, elk, antelope, and mountain sheep. In 1903, the deer season was again Populations of mule deer in most, if not all, opened for deer. The state's deer herd western states suffered at the hands of the pioneers continued its apparent decline, reaching and early settlers. No game laws or thought of pro- its lowest ebb about 1924 when the popu- tection made the mule deer, as well as other wildlife, lation for all deer on national forests targets of the pioneers for articles of food and within the state was estimated to be clothing. A few excerpts from some of the western 19,488. By 1926, the statewide deer popu- states illustrate, although incompletely given, the lation was estimated at 41,000. mule deer situation in pioneer days: (Stewart, 1967, p. 42.)

Arizona Montana No records are available, but from Population peaks reportedlv occurred some pioneer documents there was an indica- in the late 18801s, the early 1900's, and tion that deer populations were very low. the late 1920's in southeastern Montana. Many of the pioneers had to depend on The reported peak of the late 1920's was of rabbibs, etc. for protein. (Russo, 1976, small magnitude and was preceded by a personal comunication). period when many residents considered the deer extinct. (Egan, 1971). California rhere were fewer mule deer in early Oregon pioneer days than at present. . . Herds 1899 -1912 Scarce deer populations. were depleted primarily during the gold Deer generally scarce, but little hunting rush by hunting for hides and meat. pressure. Lack of roads and transportation (Macgregor, 1976, personal communication). limited harvest and there was little hunting pressure. . . -Idaho 1913-1922. . .deer continued to be The Lewis and Clark expedition of the scarce. (Anonymous 1971, p. 1.) early 1800's reports deer as well as other wild animals: Washington "On June 3, 1806, two members of their No early records, but mule were party killed five deer. . ." uncommon until about 1935. (L. D. Parsons, Peter Skene Ogden reports: 1976, personal communication.) When the party finally struggled through deep snav over the s-mit to camp on the Birch Creek side, they mote of pew deer in pioneer days. "In the many buffalo, elk, deer, and goats in the early 1800's wh& the white man first country. Ogden said, 5 wretched country, entered what is now Wyoming, he found we had hopes of finding deer, but we all wildlife in abundance, especially bison, know (now) that there are none to be seen antelope, elk, and bighorn sheep. Deer from River Malade (Magic area) to Burnt were also abundant, but apparently not in River. such noticeable numbers as the other animals. Townsend's narrative reported: Populations of big game animals Later, as the party moved across the reached a low about the turn of the cen- desert to Lost River and over to Big Wood tury." (Corsi, Wyoming Wildlife, Aug. 1974, River, they were troubled by lack of game p. 3.) and said they only killed three buffalo in severalweeks, but did find deer in good numbers on the Malade (Big Wood) River. The Alexander Ross Journals: Build Up of the Herds and Management Measures l'he Big Wood River area was 'a beaver hunter's paradise.' As the party -Utah moved along the lower Boise River in late June, they killed 17 deer and 6 elk. In recognition of the scarcity of mule deer, (Edison, 1963). the Utah legislature ended the "free ride" for hunters in Utah in 1908. The season on deer then Nevada was closed and remained closed for five years. In Deer were considered abundant in 1913, the legislature declared a season to take buck Nevada only since the 1930's. Scattered deer only with antlers 5 inches or longer. Tine kill reports of early explorers and hunters of deer during the first buck season (1914) was mention few or no deer. (McColm, 1976). recorded when "approximately 600 of these magnificent

A Historical Acco~mt and Present Status of the Mule Deer in the West MULE DEER HARVEST IN UTAH IN THOUSANDS

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the state (1973) animals were taken, and these mostly in the eastern "The increase in deer in Utah during parts of the state." (Utah Biennial Report, 1946). the past 10 years has been phenomenal ... . This increase has been due to several sources: This indeed was the turning point, as deer con- the enforcement of the buck law ..., the es- tinued to increase in numbers each year from 1913. tablishment of game refuges, the reduction Mule deer populations in Utah were given from time to in the number of predatory animals, and the time from the earliest estimate of 8,500 in 1916, to more systematic regulation of grazing on and including the estimated height of the population the National Forests." (p. 10.) in the 1945-55 period at about 375,000. These esti mated figures by the western state conservation de- Further, the next Utah Biennial Report (1928-30) partments were compiled by the U.S. Fish and Wildlife stated: Service (1937 to 1970) in a series of wildlife leaf- lets issued each year (Table 2). No claim was made by "Big game problems have, within the any state or the Service for the accuracy of the past few years, become very acute until figures. Most states stopped publishing estimated now it is imperative that remedial laws populations in the 1940's because of the inaccuracies be enacted for the correction of some of of past estimations and started using hasvest figures these unfavorable conditions. For instance, and other measurements as more accurate indicies to the deer have increased in some localities population changes (Tables 3 and 4). The Utah State until they are a menace to foothill farmers legislature in 1917 established a series of large game and fruit growers and are in severe com- preserves, which by 1923 consisted of nearly a million petition with domestic livestock for acres of the state's best deer and elk range, to pro- range forage, while the Fish and Game vide protection for these game animals. Department is without authority to remove these offending animals." (p. 9.) Recognition of the damage caused to farmlands and the competitive nature of elk with livestock resulted However, resistance to either-sex hunting was early in the establishment of the Board of Elk Control in expressed by the director of the Utah Department of 1927; later, in 1933, this organization was changed to Fish and Game. In the Utah Biennial Report of the Board of Big Game Control, with the authority to 1934-36, when populations were beginning to soar, establish regulations for all big game animals in the we find the director opposed to the suggestion that state. Its function and responsibilities have been either-sex hunting be initiated: increasingly important since its establishment. This board, composed of members of land managing agencies, "I recommend to the legislature of has membership representing federal lands, Utah Wild- this state that they do not enact a law life and Recreation Federation, Cattleman's Associa- that would permit the killing of deer of tion, Wool Grower's Association, and the Division either sex. It is our belief that 20,000 Wildlife Resources. This Board was instrumental in deer were killed last year. Under the taking action on rapidly rising deer herds and to present set-up, and should legislation be manage them on an available game and range basis. passed, we are sure our deer herds would be annihilated at the end of the third Severe winter weather, accompanied by deep snows season." (p. 5.) over much of the winter season, has had a devastating effect upon deer populations in Utah, beginning as The first indication in Utah of the need for a early as 1936- 37, again in 1939-40, 1948-49, and 1951- balanced herd of deer within the range carrying 52, and of late in 1972-73. During some of these win- capacity was given in 1939 (Utah Biennial Report, ters, more deer have died from malnutrition in local- 1936-38) : ized areas of the state than were killed by hunters (Low, et al., 1949; Hancock, 1976, personal communi- "The game animals, as well as the cation). livestock, should be reduced to the carrying capacity of the individual ranges, Undoubtedly many factors had an effect upon the giving the forage an opportunity to re- build up of deer herds in Utah, and other western produce in kind, something that has been states, during the 1920- 40 period. Predator control, neglected in the past." (p. 6.) which had its beginnings in the 1880's by stockmen, was seriously initiated in 1916, when the federal Antlerless permits were first issued in 1934. government entered the control picture. Livestock Of the 1600 permits then issued, 825 antlerless deer numbers, which soared to 275,000 range cattle and were killed. In 1935, an additional 2,008 does were 2,742,000 range sheep in the 1890'~~undoubtedly killed on special permits. brought a significant change from grass to browse ranges, which permitted deer populations to increase Antlerless deer permits were suspended in 1936 (Utah Biennial Report, 1946). Habitat losses, early and 1937 because of severe winter losses; but the recognized as results of urban sprawl, highway de- following year (1938), 4,500 permits were issued, velopment, faming practices, and others, concentrated followed by 10,700 permits in 1939 (Utah Biennial Re- or eliminated deer. Buck hunting in the first one- port, 1938-40). third of the 20th century undoubtedly contributed to population increases. The numbers of special control permits were continuously increased, until in 1961 there were approx- Pending problems were recognized early in Utah by imately 40,000 control permits issued (Table 3). Fish and Game administrators. In the 1926-28 Utah The objective of management was to bring the deer Biennial Report we read: herds closer to the carrying capacity of their ranges. The peak of Utah's mule deer numbers occurred during the 1945-50 period (with a second peak from 1964-71).

A HistoricaZ Account and Present Status of the Mule Deer in the West ' This special control permit program had started to "Many prophesied after the hunt that have its effect on the population and was reflected the deer herds adjacent to the large in the numbers of special control permits issued: cities were 'wiped out' during the first either-sex hunt, but the severe winter "By 1966 this number had been reduced of 1951-52 brought many deer down from systematically to less than 4,000 and has these same ranges to die, in some cases exceeded that number only once since then. numbers exceeding the legal harvest." In 1972, 4,106 were sold, but this number (Utah Biennial Report, 1950-52, p. 8) dropped to 1,260 in 1973. In 1974, there were no permits issued which would allow Management of Utah continued to cope with the the taking of more than one deer per hunter." large numbers of deer: (Utah Biennial Report, 1972-74). Hunter pressure increased steadily Further reaction to the needs of the growing over the years. This steady increase in herds was evident as early as 1939 when 4,078 acres hunters and liberal hunting regulations of game winter range were purchased by the Department had, by the early 1960's brought deer (Utah Biennial Report, 1938-40, p. 15). Since then, herds into better balance with forage the Utah Division has been dedicated to a program of resources. winter range acquisition, with a goal of 577,000 acres of winter range under their management program. To The Board of Big Game Control, date, about 225,000 acres have been acquired acting on the recommendations of the (Hancock, 1976, personal communication). Division of Wildlife Rescurces and other resource management agencies, began a The bounty system was initiated in Utah in 1938 systematic cutback in control permits and to further reduce predators. Lions were bountied at liberalized seasons at about this time. $10, and bobcats and coyotes at $2.50. At this time, (Utah Biennial Report, 1972-74) the Department entered into an agreement with the Bureau of Biologj.ca1 Survey for more effective preda- The reduction in the number of tor control. special permits available was a direct result of the deer being more closely Further pressures were exerted for either-sex balanced with proper winter range con- hunting as early as 1938: ditions and hence a lesser need for additional deer removal. (Utah Biennial There is yet some agitation for a Repor" 1964-66, p. 10) general open season on deer of either sex. We believe this would prove disastrous Further : and is entirely unnecessary for proper control. (Utah Biennial Report, 1936-38, Deer management plan in Utah has p. 44.) largely achieved its objective. As judged by the harvest, range trends, and In 1943, the Interagency Big Game Committee was other factors, the population is generally organized. It consisted of one representative each stable and in balance with the habitat. from the U.S. Forest Service, the Bureau of Land (Utah Biennial Report, 1970-72, p. 13) Management, and the Department of Fish and Game, whose duties as land managers was to determine big game con- And finally: ditions in the state and give recommendations to the Board of Big Game Control for the establishment of Deer management continued to follow seasons, limits, and other matters pertaining to big the course established in the 1960's. game. The objective of bringing herds into balance with their range had largely The recognition of the need for either-sex hunt- been achieved at that time and cut ing seasons was now expressed by the director in 1946 backs in control permits and liberalized (Utah Biennial Report, 1944-46): seasons were indicated. (Utah Biennial Report, 1972-74, p. 40) There is a growing feeling toward a license to kill a deer regardless of sex Recent changes in the regulations further reflects to substitute the present "buck law", a decline or lower numbers taken formerly in herd but this might prove disastrous to some of populations : our deer herds, unless a method of control of the number of hunters permitted on a Concurrent with the reduction in given area were also to be provided. (p. 33). control permits, the number of herd units with liberalized seasons also began a Supplemental feeding of big game had been spo- general decline. In 1961 and 1962, the radically practiced in Utah in the late 19301s, but number of herd units with seasons more the severe winter of 1948-49 brought an emergency liberal than the 11-day either-sex season feeding program for big game not only in Utah, but in was 28. By 1966 this had dropped to 4. many northern Rocky Mountain states (Law, 1950). In 1974, there were no seasons more liberal than the 11-day either-sex season; in A 54 percent hunter success in Utah in the de- fact, the most liberal seasons in the cade of the 40's jumped to 84 percent under the first state in 1974 were those allowing the "Either ex" law season, 1951, for a total harvest of hunting of antlerless deer for the last 101,000 deer. seven days and those allowing antlerless

A tiistorica2 Account and Present Stutus of the 8 Mu?ulc iiecr in the West hunting the first three days of the season. Arizona In 1961 there had been no units with regulations more restrictive than the If we can use the Kaibab as an general 11-day either-sex season. These example, what happened there happened more restrictive hunts increased steadily statewide. A tremendous herd build-up from 1961 to 1969, then sharply to 1973 in the early 1900's and then a sharp die- when 31 herd units had seasons more re- off about the mid-20's. However, in strictive than the 11-day either-sex our more recent history, the date would season. Types of restrictive seasons have be 1952-58. (Russo, 1976, personal included hunts shortened to 5 days, a communication) combination of 3 days either-sex hunting follmed by 8 days of buck-only hunting, Records showing the yearly deer har- 4 days of buck-only hunting follwed by vests and the number of hunters it took to 7 days of either-sex hunting, and a full bring them about are pretty sketchy for season of buck-only hunting. (Utah Big the years prior to 1946. Since then, Game Harvest Handbook, 1974, p. 7.) though, accurate records have been kept, and they show a steady increase in the The decline in the herds, however, may not have annual harvest to a high point in 1961, been all a result of management to get herds within followed by a gradual decline to a low their carrying capacity, particularly during the past in 1968. Buck-only harvest, which also few years. During the past several years, more evi- topped out in 1961 at 26,627 animals, hit dence is at hand that adverse weather--abnormally its modern-day low point of 17,094 in cold and long winters and prolonged cold and wet 1965 and has climbed slowly since then. springs--has had an effect upon the productivity of some of the herds, especially in central and south- During the late 50's and early em Utah. The hard winter of 1972-73 took a toll of 60's, Arizona was experiencing a boom in fawns, which reduced fawn survival in some units to its deer population. Range conditions 31 fawns per 100 does. Further, drought conditions were critical and winter die-offs were in 1971-72 and in 1972-73 in southern and eastern common. The seasonal regulations during Utah adversely effected the growth of vegetation upon this period reflected the Departments' which lactating does and weened fawns depended, which concern through large numbers of any- resulted in lower fawn survival. Adverse weather deer permits, and many areas where does conditions, coupled with an increase in antlerless were legal with no special permit. By removal in 1971-72-73 in the central part of the about 1963 the peak in populations had state, undoubtedly had an adverse effect upon the subsided, and while ranges were still in present declining population of mule deer in Utah poor condition, the any-deer hunting (Hancock, 1976, personal communication). again became more restricted. This policy has continued to the point where in re- In summary, the present status of mule deer in cent years, only a very small number of Utah appears to be one of declining populations un- any-deer permits has been authorized. doubtedly influenced by many factors such as depleted (Anonymous, 1970) ranges that have not yet recovered from past overuse, drought, cold hard winters, habitat loss from highway California construction, summer homes, and plant succession as fewer cattle are grazed. Coupled with these factors Longhurst et al. 's (1976) recent summary docu- may be the influence of predation from feral dogs, ments the decline and gives management suggestions coyotes, and other predators, as well as poaching. to restore deer numbers. -Idaho Other States Population of deer increased from post-pioneer days to the present time: Estimates given in the To detail the build-up in numbers of mule deer literature show the following deer population in- in most western states would be to duplicate in a creases and subsequent decreases to present numbers: large measure the picture in Utah. Most states have shown exploding populations during the first half of 45,000 the century, accompanied by efforts to reduce herds 75,000 by greater hunter harvests of one kind or another. 137,717 Habitat improvement, winter range acquisition, and 315,000 other management practices have been followed. down 30 -+ X 215,000 Populations in most western states peaked in the (Thiessen, 1976, 1940fs, 50ts, and 60's, as in Utah, and populations personal communication) now appear to be declining even further. In a recent paper by Longhurst et al. (1976), the California Montana mule deer decline is detailed and possible remedial measures given. There are many indications that the peak mule deer populations which began in A few excerpts from some of the game managers in the late 40's and extended into the late the western states indicate the population changes, 50's and early 60's were greater than has harvests, and measures used to manage the herds: occurred in the past hundred years. How- ever, there apparently has been considerable

9 A Historical Account and Present Status of' the Mute Deer in the West change or fluctuation in numbers of deer creased since then. (L.D. Parson, 1976, during the past hundred years in various personal communication) areas throughout the state. Wyoming Thus, during the period 1941-69, mule deer not only increased in number, What has happened to our deer herd? but also expanded in distribution over This is a question game managers encounter the entire state, with peak numbers and frequently today and certainly it is a distribution being reached around 1950- proper one. Mule deer populations are not 55. There has been little change since. as they were in the late 1950's and 1960's. (Corsi, 1974, p. 3) The "Buck Law" of the 30's and 40's resulted in few deer harvested and instilled in the minds of many that shooting does and fawns was sinful. Trends in Mule Deer Populations on Specific Units

Montana has even employed late win- Well-documented data shaving long time trends ter hunts in an effort to bring deer into in deer populations are difficult to find. Except balance with their range. Such seasons for the first example, we have selected areas where were often met by much public criticism. pellet group counts formed the basis for estimating The mule deer management program in Mon- relative intensity of deer use of the range. tana has reached an "hour of decision". We must in some manner reduce deer to the ex- Information from the Kaibab (North) National tent the ranges can recover. Forest, although based on estimates, is the classical example of what has happened to many of our The re-establishment of doe seasons mule deer herds (Figure 2). The history of the in 1950 and 1951 gave more people an Kaibab is the story of many of the deer herds of the opportunity to hunt and take deer. West. The boom was apparently from 1918 (Forest (J. Egan, 1971) Ranger reports of heavy over-utilization) to 1923-24 followed by the drastic starvation during the next Since 1970, ~ontana'smule deer herds few years. Estimates, by our most experienced men have continued to decline. (Allen, 1976, of the time, went from 100,000 in 1924 to less than personal communication) 30,000 in 1930. Numbers were still high for this depleted range as indicated by the fact that until Nevada 1935, Supervisor Walter Mann had a standing offer of $1 for every aspen shoot over 12 inches high that Since the early 1960ts, all deer could be found on the Kaibab. In 1936, however, at herds in eastern Nevada have shown the isolated spots, a few aspen sprouts began to "get- same population trend; populations de- away" from deer. clined during the early 19601s, bottomed out in 1965 and 1966, expanded until 1971, A personal visit in 1942 (Julander personal and have declined since then. (McColm, files) shaved rather extensive areas of good aspen 1976) reproduction developing over much, but not all, of the forest; agreeing with the estimates that deer At the present time, we feel we are numbers were at a low in the late 1930's and early experiencing a decided and very drastic 1940's. crash in the populations of eastern Nevada.. . (Christianson, 1976, personal Estimates of deer numbers could not be found be- communication) tween 1947 and 1969, but another visit in 1954 (Julander personal files) showed a sharp deer high- Oregon line on the newly established drop of aspen, indicating a higher deer population. During the winter of Build up of herds peaked in 1953 1954-55, the Arizona State Game and Fish Department and 1967. Liberal season 1955 stabilized (Swank, 1958, p. 78) estimated a loss of 18,000 deer. herds in 1967. Fawn ratios and fawn sur- In the fall, 1954, a total of 8,058 deer were har- vival declined and so did population. vested. This is the largest annual kill on the 1945 150,000 estimated populations Kaibab (North) to date, but it was too little and prior 1967 575,000 estimated populations too late. 1975 400,000 estimated populations Fawn survival was the most important Clay McCullough's estimates of deer density from factor in population decline. (Ebert, 1969 to 1975 inclusive, based on pellet group counts, 1976, personal communication) on the higher portion of the Kaibab sumer range (575 miles), gives a reliable picture of trend in Washington numbers for that period (Figure 3). The Kaibab herd again appears to be on a slight upward trend since The winter of 1889 seriously depleted 1971. or reduced herds. Build-up of large herds occurred between 1935 and 1950 with largest Data from Robinette (personal letters) on the herds believed present in 1947-50, 1955, Oak Creek deer range in Utah on estimated deer herd 1963, and 1968. Mule deer hit bottom in numbers over an 11-year period are well documented. 1969, 1971, and 1972 and have slowly in- Deer numbers were estimated by pellet group counts over the entire winter range.

A Histor-icaZ Account and Present Status of tne Mule Deer in the West 0-4NC?.jY1\9hmrnNNgz.,,3ma,.mm03Nn3Y1\9,. N nmmn mz28g282mmmmmmmmmmmmmm nm*u~3*3uu mmmmm 33343333~33-43433434d33r(33333

YEAR

Figure 2. Estimated mule deer numbers on the Kaibab (north) National Forest (From D. 1. Rasmussen, 1941, and U. S. Forest Service Unpublished Reports.) YEAR

Figure 3. Estimated mule deer numbers on the Kaibab (north) National Forest summer range (from pellet group counts); (Data from Arizona Game and Fish Department). The deer population of this unit reached peak damward trend is indicated. However, a high pop- numbers in about 1942 and declined some by 1946 when ulation was still evident during this period (Fig- studies began. Over the 11-year period, 1946-1955 ure 6). Summer range is of higher quality than on the inclusive, estimated numbers did not vary greatly and Henry Mountains. (Patterson and Harper, unpublished no definite trend, up or down, is indicated (Figure 4). data). Efforts were made through liberal doe permits, to reduce this herd to proper carrying capacity with no Data from the Arizona Game and Fish Department success. show the trend in relative density of mule deer, as determined by pellet group counts, on the Three Bar During the period 1958-1975, with less intensive Wildlife area in Arizona from 1959 to 1975 (Arizona samplings, estimates of deer use at Oak Creek was de- Game and Fish Department, personal correspondence). termined by deer days use and percent utilization of (Figure 7). A general decline, from a higher deer key species (Figure 51, Utah 1952-1975. (Data from density in 1959-60 to a much lwer density in 1969, is Utah Division of Wildlife Resources.) Both estimates indicated. From 1969 to 1975 the density appears to indicate a reduction in herd numbers from 1958 to be stabilized at a rather low level. 1966 with a definite lower population in 1966, '67, and '68. This was followed by a rather rapid upward On all of the above areas, the objective of trend from 1969 to 1975 to a population apparently management has been to bring mule deer numbers within nearing carrying capacity. History of this herd carrying capacity of the range. The different results differed from the Kaibab since the decrease from peak shown indicate varying degrees of success and possibly numbers were not so drastic and the range, although different causes and different management. damaged, was far less severe than the Kaibab. This herd had only a little above average winter losses in From general information obtained from most of 1948-49. However, summer range is somewhat limited the western states, there is no doubt that mule deer and of low quality. populations are down as of 1975. However, investigations of individual herd units (with intensity of On two neighboring, rather isolated mountain deer use documented by pellet group counts) indicate ranges in southeastern Utah, the Henry and the LaSal, that, although deer numbers are much below an ex- deer days use per acre was determined by pellet tremely high peak, populations since then, and par- group counts (Utah, 1952-75). Here, as at Oak Creek, ticularly during the last six or seven years, seem to the peak in deer numbers were believed reached and be leveling off, or in some cases, increasing. some decline made before data collecting began in Based on the overall picture, we ask: "Will the 1945-46. The Henry mountain herd shows a sharp de- trend continue down? Can management of herds and cline, reaching a low point in 1956 (Figure 6). From habitat reverse the downward trend and stabilize or that low point, a slow recovery is indicated. This increase the herds? What are the causes of the de- range was badly depleted by both deer and livestock cline and possible solutions? and was low in forb production on summer range. Based on individual herd data, we ask: "Are Average deer days use per acre on the LaSal our mule deer herds, in general, declining below mountain reached a low point in 1949 followed by a desirable levels which will permit recovery of de- rather vigorous rise from 1953 to 1955 indicating a pleted ranges, or are they adjusting in size to the fairly-productive herd. From 1955 to 1975, a slow actual impared carrying capacity of their habitat?

We hope the above questions will be answered, or at least enlightened, in the following papers of this symposium.

13 A Historical Account and Present Status of the Mule Deer in the West YEAR

Figure 4. Mule deer population for the Oak Creek herd unit, Utah, 1946- 1956. (Data from W. L. Robinette and 0. Julander and Utah Division of Wildlife Resources). oomorrwm ~ma~.oomo~wm "Imaaaa aaaaaLaI.I.r.I.2-I. m m O\mmm 4 mmmmmmmmmmmcn d 4 444 444 4 4 4 4 4 +44 + YEAR

Figure 5. Measure of mule deer use on Oak Creek winter range, Utah, 1957-1975. (Data from Utah Division of Wildlife Resources). -LaSal Mountain deer herd ------Henry Mountain deer herd

Figure 6. LaSal and Henry Mountains, Utah, deer days use per acre estimated from pellet group counts. Data collected in early spring of each year by Utah Division of Wildlife Resources. YEAR

Figure 7. Mule deer population for the Three Bar Wildlife Area, Arizona. Population density based on pellet group counts (November and December data) by Arizona Game and Fish Department. LITERATURE CITED Corsi, R. M. Anonymous. 1968. Deer and public management. Proc. West. 1928. Biennial Report of the State Fish and Assoc. State Game and Fish Corn., 48:255-257. Game Commisioner of the State of Utah, June 30, 1926, to June 30, 1928, 22 pp. Corsi, R. M. 1974. A potpourri of deer facts. Wyoming Wild- Anonymous. life, Aug. p. 3. 1930. Biennial Report of the State Fish and Game Commissioner of the State of Utah, Edison, M. July 1, 1928, to June 30, 1930, 21 pp. 1963. Idaho wildlife in early days. Idaho Wild- life Review. July - Aug. 1963, p. 8-13, and Anonymous. Sept. - Oct. 1963, p. 8-12. 1936. Biennial Report of the State Fish and Game Commissioner of the State of Utah, Egan, J. July 1, 1934, to June 30, 1936, 63 pp. 1971. Game management in Montana. Chapter 6 on mule deer, p. 53-79. Anonymous. 1938. Biennial Report of the State Fish and Greenley, J. C. and M. Humphreys. Game Commissioner of the State of Utah, 1964. The decline in the 1962 mule deer harvest July 1, 1936, to June 30, 1938, 45 pp. in Nevada. Proc. West. Assoc. State Game and Fish Comm., 44:173-176. Anonymous. 1940. Biennial Report of the State Fish and Haines, A. L. Game Commission of the State of Utah, 1955. Journal of a trapper. (1834-1843) by July 1, 1938, to June 30, 1940. Osborn Russell. Edited by Aubrey L. Haines, 191 pp. Anonymous. 1946. Twenty-sixth Biennial Report of the Hancock, N. V. State Fish and Game Commission of the State 1964. Mule deer harvest decline in Utah. Proc. of Utah, July 1, 1944, to June 30, 1946, 78 pp. Est. Assoc. State Game and Fish Cm., 44: 181- 188. Anonymous. 1952. Thirtieth Biennial Report of the State Hancock, N. V. Fish and Game Commission of the State of 1968. Major factors influencing mule deer pop- Utah, July 1, 1950, to June 30, 1952, 78 pp. ulation and harvest trends in Utah since 1962. Proc. West.- - Assoc. State Game and Fish Comm.. Anonymous. 48:245-252. 1966. Thirty-seventh Biennial Report, Utah State ~e~artientof Fish and ~ame; July 1, 1964, Lauchart, J. B. to June 30, 1966, 44 pp. 1968. Mule deer management in the state of Wash- inaton. Proc. West. Assoc. State Game and Fish Anonymous. Comm., 48:253-254. 1970. Forty years of progress, Game Management, Arizona Wildlife Views, p. 19-20. Longhurst, W. M., E. 0. Garton, J. F. Heady, and G. E. Connolly. Anonymous. 1976. California deer decline and possibilities 1970. Game Management, Forty years of progress, for restoration. Western Section of the Wildlife Arizona Wildlife Views, p. 16-22. Society and the California-Nevada Chapter of the American Fisheries Society. Fresno, California, Anonymous. January 30-31. 16 pp. + tables, figures, and 1971. History of big game regulations, 1899- literature cited. 1970. Deer section Oregon Dept. of Fish and Wildlife, 7 pp. Low, J. B. and W. B. Low. 1949. Deer losses on the =he deer herd, win- Anonymous. ter, 1948-49. Special Report of the Utah Co- 1974. Forty-first Biennial Report, State of operative Wildlife Research Unit. Oct. 1, 18 pp. Utah, Division of Natural Resources, July 1, 1972, to June 30, 1974, 52 pp. Low, J. B. 1950. An analysis of the 1948-49 emergency Anonymous. feeding programs for wildlife in the Northern 1974. Big game harvest report. Utah State Rocky Mountain Region. Northern Rocky Mountain Division of Wildlife Resources. Completion re- Wildlife Society, Jackson, Wyoming. March 29- port for Federal Aid Project W-65-R-D-23. Pub- April, 20 pp. lication No. 75-2. March 31, 94 pp. Macgregor, W. G. Anonymous. 1964. Analysis of Great Basin deer decline - 1952-1975. Utah big game investigations and Calif. Proc. West. Assoc. State Game and Fish management recommendations. Issued annually by Comm., 44:167-169. the State of Utah, Department of Natural Re- sources, Division of Wildlife Resources.

A HistoricaZ Account and Present Status of the 18 Mule ileer in the West Macgregor, W. G. Reynolds, T. A. 1968. Major factors influencing mule deer pop- 1960. The mule deer, its history, life history, ulations and harvest trends in California since and management in Utah. Utah State Department 1962. Proc. West. Assoc. State Game and Fish Fish and Game. Dept. Informative Bulletin No. Comm., 48:215-218. 60-4, 32 pp.

McColm, M. A. Russo, J. P. 1976. Mule deer population trends in north- 1968. Major factors influencing mule deer pop- eastern Nevada and influencing factors. The ulation and harvest trends in Arizona since 1962. Nevada Section of the Society for Range Manage- Proc. West. Assoc. State Game and Fish Corn., ment and the Nevada Chapter of the Wildlife 48:209-214. Society, Elko, Jan. 10, 16 pp. Stein, R. H. McKean, J. W. and I. D. Luman. 1968. Oregon's mule deer population and manage- 1964. Oregon's 1962 decline in mule deer har- ment program since 1962. Proc. West. Assoc. vest. Proc. West. Assoc. State Game and Fish State Game and Fish Corn., 48:241-244. Comm., 44:177-180. Stewart. R. H. Mohler, L. L. 1967. New Mexico wildlife management. New 1964. Deer harvest fluctuations in Idaho. Mexico Department of Game and Fish. Chapter 8, Proc. West. Assoc. State Game and Fish Comm., Mule Deer, March, p. 42-51. 44:170-172. Snyder, W. A. Nielson, A. E. and R. M. Williams. 1968. Major factors influencing mule deer pop- 1968. Major factors influencing mule deer populations and harvest trends in New Mexico. ulation and harvest trends since 1962 - Idaho. Proc. West. Assoc. State Game and Fish Comm., Proc. West. Assoc. State Game and Fish Comm., 48:237-240. 48:232-236. Swank. W. G. Rasmussen, D. I. 1958. The mule deer in Arizona Chapparal, State 1941. Biotic communities of Kaibab Plateau, of Arizona Game and Fish Department, Wildlife Arizona. Ecological Monographs 3:229-275. Bulletin No. 3, February, 109 pp.

A HistoricaZ Account and Present Status of the 19 Mule Deer in the West MULE DEER HABITAT CHANGES RESULTING FROM

LIVESTOCK PRACTICES

Philip J. Urness

Assnciate Professor and Project Leader Utah State University Range Science Department and Utah Division of Wildlife Resources

Abstract

Livestock grazing has had great influence on mule deer habitats since intensive settlement in the latter half of the 19th century. Positive and adverse effects have resulted from vast successional change, land preemption for cultivated crops and habitations, and activities associated with livestock production. Exploitative grazing during the "open range" era and widespread burning of montane forests set in motion sweeping habitat changes. Deer then increased greatly after conservation programs and intensive predator control in the early 1900's reduced mortality below recruitment. Although these habitat changes were largely unplanned, they must be considered in present- day management since adjustments in past practices can be expected to alter deer carrying capacities and populations.

Mule deer (Odocoileus hemionus) are a western Historical Perspectives North American form that, considering all subspecies, have broad ~.cclogicalamplitude. They occur, at least Any discussion of how the livestock industry seasonally, from hot and cold deserts to montane might influence an apparent decline in mule deer forests and alpine tundra (Figure 1). The major populations must be viewed in developmental as well commonality in this broad geographic variation is as current perspective. That a general decline has mountairs, including importantly the foothills or occurred since the mid-1960's is not a point of bajadas. Rather few mule deer occupied flatlands and debate, thus the impetus for our symposium. However, these were quickly supplanted by modem man's agri- the decline may be of lesser magnitude than some culture and other developments. Consequently, a would have us believe, at least in the central consideration of livestock practices, as they impact portion of mule deer distribution (Figure 2). While mule deer, essentially deals with ecology and manage- we are presently below the peak harvest years in Utah, ment of foothill and mountain vegetation. much of the drop is accounted for in near-elimination of antlerless animals in the harvest. Examination Complicating elements immediately emerge when of the buck-only harvest curve suggests much less attempting to cover a general topic such as this. change, although the dow~lward trend accelerated These elements include (1) migratory populations during the past three years. occupying distinct winter:summer ranges in northern and high elevation southern areas vs. nonmigratory Trends in range livestock numbers in Utah show populations occupying desert, chaparral, and coastal some significant changes that reflect similar zones, (2) very different responses of diverse vege- patterns over much of the Intermountain West tation types to specific management practices such as (Figure 3). One of my professors, a prominent class of livestock, season and intensity of use by zoologist, occasionally would lament the presence livestock, and fire use or suppression, (3) varying of domestic sheep on mounrain ranges. It was his periods and causes of stress affecting survival and belief that elimination of "mountain maggots" from productivity of deer (i.e. winter forage scarcity and the range would usher in a new deal for mule deer deep snow in northern latitudes or high elevations; based on a narrow concept of strong dietary overlap. summer drought and forage quality restrictions in The steady decline in the range sheep industry has southern latitudes). not borne out his prophecy.

21 Pule Deer Habitat flanges Resulting from Livestock Practices An extensive literature attests to general 1915). Longterm protection from grazing or light abusive rangeland use by livestock over most of grazing did not materially affect growth of woody western North America from rerid-19th century settle- plants nor prevent their expansion (Blydenstein et ment, up to the present in some cases. The period of al. 1957, Glendening 1952). Once started the major abuse was generally from 1880 to 1930, with process was probably accelerated through propagule foothills around valley settlements affected earliest. dispersal by birds, rodents, and other biotic factors (Arnold 1942, Reynolds 1950, Reynolds and Glendening Unrestricted selective grazing by livestock, 1949, Timmons 1942). especially in spring, on the palatable grasses and forbs led, in part, to widespread successional change A combination of some or all of these factors favoring shrubs that were frequently subordinates in is probably the most accepted explanation of woody presettlement vegetation (Ellison et al. 1951, Hull plant invasion in desert grasslands. Regardless of and Hull 1974, Leopold 1950, McConnell and Dalke causal factors, the effect in terms of mule deer was 1960). On many areas outright invasion of grasslands a considerable expansion of yearlong habitat which by woody plants and succulents occurred (Blackburn the cacti and shrub fruits, browse, and cover and Tueller 1970, Glendening 1952, Humphrey 1953, provided. Reynolds and Elartin 1968). Causes for increases in woody plants have been variously ascribed to excessive Sagebrush:bunchgrass: Sagebrush (~rtemisiaspp. ) grazing, fire suppression, promiscuous burning, cli- was a~~arentlv. . dominant in the climax community on matic change, biotic factors besides grazing, and the drier areas and on certain soils of this type combinations of these factors, depending upon vege- with bunchgrasses--wheatgrasses (Agropyron spp. ) , tation type. bluegrasses (Pod spp.), and needlegrasses (Stipa spp.)--and forbs prominent in the understory. With Successional Relations heavy, selective grazing, especially in spring, the grasses declined and sagebrush and other shrubs Although much foothill habitat was pre-empted increased in density (Robertson 1971, Stoddart by agriculture, additional carrying capacity on 1941, Tueller 1973, Tueller and Blackburn 1974). remaining habitat was created through progressive and Where fires occurred, retrogression proceeded to retrogressive successional change resulting from weedy annuals, especially cheatgrass (Bromus excessive grazing, altered fire patterns, and logging. tectorum), and sprouting shrubs (rabbitbrush These changes were sufficiently widespread to permit Chrys thamnus spp. , and horsebrush Tetradymia spp.) . mule deer increases to unprecedented numbers from Active fire suppression limited areas burned so big about the 1930's to 1950's (Leopold 1950, Leopold sagebrush dominated very large tracts and, besides, et al. 1947, Longhurst et al. 1952). it reestablishes rather quickly on such sites following fire (Blaisdell 1953). Influence of early livestock grazing was imposed on all vegetation types affecting mule deer, but The more mesic foothills apparently exhibited a impacts differed sufficiently to require separate grass:forb-dominated climax with shrubs more widely discussion. In general, fire exclusion in arid or spaced (Hull and Hull 1974, Pickford 1931, semi-arid types and widespread uncontrolled burning Stoddart 1941). Intense use in spring reduced the in montane forest types accompanied grazing and herbaceous understory followed by great increase positively affected habitat values for mule deer. in sagebrush, rabbitbrush (Chrysothamnus spp.) , and Major types are desert grassland, sagebrush:bunchgrass, some more palatable shrubs such as bitterbrush, chaparral, juniper:pinyon,and montane forest. Purshia tridentata (Pickford 1931). Soil erosion and site verification appear to have played prom- Desert grassland: Extensive grassland areas in inent roles in this process (Ellison 1954, 1960, the Southwest and Mexico were heavily stocked with Leopold 1950). Increase in palatable shrubs Were cattle after 1800 (Humphrey 1958). Although Spanish more likely to occur where cattle grazed, less so settlement had introduced cattle, sheep, and horses with sheep (Cottam and Evans 1945). Fall use alone in the 1500ts, use was generally restricted to areas was not nearly so likely to effect composition immediately around widely scattered towns as a result shifts favoring shrubs (Mueggler 1950). of Indian raids. Woody plants occurred sparsely throughout the grass-dominated uplands and in bosques Generally, the carrying capacity for deer on along stream courses. With heavy use after 1880, the foothill winter ranges was increased with greater palatable grasses, mostly gramas (Boutaloua spp.), shrub density where fire was excluded (Julander three-awns (Aristida spp.), and hilaries (Hilaria 1962). Later, regulated spring livestock use spp.), were quickly reduced under heavy year-long maintained this condition but late summer and fall use. Nesquite (Prosopis spp.), other leguminous and use removed a considerable amount of the palatable non-leguminous desert shrubs, and cacti increased browse upon which deer depended for winter range. (Figure 4) and assumed dominance on very great areas (Bentley 1898, Branscomb 1958, Brown 1950, Chaparral: Grazing and fire have been Glendening 1952, Humphrey 1953). inextricably interwoven in the development of most, if not at all, chaparral types occupied by mule Conflicting reports variously ascribe vegeta- deer. Zn Arizona, the presettlement type apparently tional change to climatic shift toward increasing presented an open, grass-dominated aspect with aridity (Schulman 1956, Branscomb 1958), heavy shrubs present but heavily suppressed by frequent grazing reducing competition from herbaceous species fires carried over large areas with heavy amounts of (Buechner 1944, Whitfield and Anderson 1938, herbaceous fuels (Leopold 1924, Croxen 1926). The Glendening 1952), and fuel reduction preventing bimodal precipitation pattern favored grass:forb periodic fires (Griffiths 1910, Humphrey 1958, growth when fires k,,pt shrub competition down. Heavy Reynolds and Bohning 1956, Thornber 1910, Wooten post-settlement grazing, mostly by cattle, quickly

Mule Deer Habitat Changes Resulting from Livestock Practices reduced herbaceous fuels and fire frequency. Shrubs created in 1905, an increasingly abusive pressure and woodland trees increased dramatically. The was placed on mountain summer ranges. Grazing on present-day aspect is one of dense tall shrubs, Forest Service lands was placed on a controlled typically sclerophyllous and evergreen, with little lease system which became increasingly more effective herbaceous understory unless recently burned. Al- in reducing abuses after 1910. A number of reports though the type offers great cover value, the quantity emanating from the Bureau of Plant Industry, state of high-quality forages is limited during droughty agricultural experiment stations and other U.S.D.A. periods before and after summer monsoons (Swank publications appeared about this time documenting the 1958). "tragedy of the commons" (Griffiths 1902, 1903. Kennedy 1901, 1903, Wooten 1908). California chaparral had a somewhat different history as well as a distinctly different climate. Some later papers indicate improvement with Long hot, dry sumers favored brush species dominance. grazing control but attest to the slow recovery and Purposeful burning was more prevalent after 1850 than severity of damage sustained (Darlington 1915, during Indian or Spanish domination (Taber and Forsling 1931. Humphrey 1943, Pickford 1931, Dasmann 1958, Sampson 1944). A major expansion of Sampson and Weyl 1918, and many others). In brushfields upslope into previously forested areas addition to overgra-ing, purposeful burning occurred occurred with early logging and burning, especially on many mountain ranges to stimulate forage and make in the Sierra Nevada (Longhurst et al. 1952, Sampson dense brushfields and forested areas more accessible and Jesperson 1963). Frequent burning was done to livestock, especially sheep (Reynolds 1911, primarily to increase livestock forage quality and Ellison 1954). Soil erosion and denudation of palatability. Expansion of chaparral into valley vegetation from grasslands and forests led to grasslands and oak-woodlands was ascribed to over- invasion or thickening of xerophytic shrubs (Ellison grazing, reduced competition from grasses, and 1960, Eliison et al. 1951). reduced fire frequency (Leopold 1950, Shantz 1947). Slash fires on logged areas and wildfires swept Carrying capacities for mule deer were (and are) over staggering acreages of forest throughout the greatest on areas in continuous cycles of secondary West from the late 1800's to about 1940, creating succession where a mix of grass, forb, and shrub large brushfields that were grazed heavily by live- forages was available. Moderate levels of livestock stock and provided excellent habitat for deer, use and frequent small fires of varying age, from albeit at great cost (Sampson and Jesperson 1963, newly burned to mature brushfields in close juxta- Leopold 1950). The rapid cycling of accumulated position, provided productive yearlong or winter deer soil nutrients to deer forage was probably responsible, habitat (Biswell et al. 1952, Cronemiller and to a considerable extent, for tremendous population Bartholomew 1950). increases during this period along with concomitant control of livestock grazing, predator populations, Juniper-pinyon: As in the case of other arid and deer exploitation (Julander 1962, Longhurst or semi-arid types, woody plants in the juniper- et al. 1952). pinyon zone have expanded in total area during the past century. Extension of trees into grassland and Secondary succession to closed canopy forest shrub steppe occurred both upslope and down (West on many of the burned areas is rapidly reducing et al. 1975). The causes were no doubt complex carrying capacity of deer summer range (Hines 1973, but overgrazing and fire suppression appeared prom- Leege 1959, Loope and Gruel1 1973, Lyon 1966, inent as initiating mechanisms (Blackburn and 1971). Prescribed burning and other forestry and Tueller 1970). Climatic change and biotic influences range management practices that integrate forage have also been implicated (Frischknecht 1975, and timber production will be necessary on many LaMarche 1974, Phillips 1910, Schulman 1956). montane forest areas in future if important summer range values affecting deer productivity are to be Cover values, primarily, and browse forage maintained. provision accompanying shrub and tree invasion of grasslands increased mule deer winter range (Terrill Successional change: Mule deer are adapted to and Spillett 1975, Reynolds 1964). In the absence mid-successional communities that contain a good mix of renewal by fire or mechanical means, however, the of grass, forb, and shrub species, but especially trees become dense and practically eliminate the browse communities in winter. Changes leading away understory, including many shrubs, especially in the from such conditions usually adversely affect deer Great Basin (Julander 1962, Tausch 1973). carrying capacity where they occur over extensive Consequently, the increased habitat values wrought areas. Management of succession, then, is the by tree invasion have been somewhat ephemeral, with business we are in if optimization of harvestable early gains declining in late succession. This has game is our goal (Leopold 1950). been the basis for widespread tree control projects, namely, to set succession back to a phase more Unless site potential has been seriously productive for livestock and deer (Dwyer 1975, altered, processes of past change can be reversed Plummer et al. 1968). and this in no way excludes those wrought by grazing. Indeed, on many areas determined to be best managed Montane forest and uplands: Higher elevation, without livestock use, municipal and other watersheds forested and non-forested areas provided summer range come to mind, we can observe secondary succession for large local livestock herds, especially sheep toward the climax community. A good example is the after 1870. These were usually inflated by itinerant Wasatch Front in Utah, at least portions of it. herds trailed or shipped in from long distances to Removal of growing season livestock grazing has been graze the "open range." Until the forest reserves followed by surprisingly rapid recovery of bunch- were established around 1900 and the Forest Service grasses and forbs with a corollary reduction of

23 Mute Deer Hahitot Changes desesutting from Livestock Practices shrub cover (Smith 1949, Stoddart and Smith 1955). Pase rt al. 1967, Taber and Dasmann 1958, Urness 1975). Creation of vegetational diversity often Fire in susceptible types such as sagebrush: has provided high-quality forage resources, grass can hasten progression through heavy reduction unavailable on unaltered stands, which can be of shrubs. Where disclimaxes are the desired seasonally important to mule deer (Plummer et al. objective, as in juniper-pinyon, fire or mechanical 1968). Thus green crested wheatgrass is sought by control is a necessary element to avoid canopy closure deer from fall to early spring when other available and loss of understory (Plummer et al. 1968). forages, mostly browse and indispensible, are much Generally, succession proceeds slowly and there is lower in value (Koehler and Leckenby 1970). presently little evidence, outside of some montane forest types, that it is responsible for short-term Shifts toward management objectives that declines of mule deer. However, extensive change emphasized created mosaics to provide treatment toward a grassland, woodland, or forest climax can benefits while retaining values innate to the be expected to reduce deer carrying capacity over the untreated community have been very recent. They long term. This should be anticipated in any resource came with the growth of environmental concerns after plans and action (or inaction) programs that lead to the mid-1960's. Planned diversity of cover types significant shifts in plant communities. We have been through small projects that blend naturally into the remiss in not monitoring change more closely. landscape became accepted managerial policy (Forest Service 1973, Tausch 1973). However, by Current Management Status then social, political, and economic pressures were so great that a near abandonment of such programs My assignment unavoidably parallels later has ensued. We have, in effect, thrown out the symposium papers in several areas; namely, predator baby with the bath. control, vegetation manipulation, and competition. As much as possible, an attempt has been made to While the decline of deer is coincident with a avoid specific consideration of these and related winding down of vegetational control programs on topics, but they cannot be completely ignored since public lands, there is no suggestion of a cause: they are an integral part of livestock production on effect relationship. Conversely, there is little most rangelands. Livestock practices frequently case for argument that a "critical mass" of treated affect food: space relations (nutrition and behavior) land finally exceeded an upper threshold which was of mule deer and the elements of competition and followed by a crash in deer numbers. Most treatments habitat destruction are potentially strong. were accomplished well before a decline in deer numbers. To my knowledge, no one has demonstrated Adjustments of livestock numbers to a carrying a pattern in population levels that parallels capacity that recognizes allocation of resources to differences in amount of treated area. diverse uses has come a long way (Smith 1958, 1959), yet there is still need for much improvement on Grazing systems: Grazing systems that provide public rangelands (Bureau of Land Management 1974). some rotation or deferment of livestock use are Our task is to identify the forces of ecological increasingly adopted on public lands as capital change put into motion by nearly a century of exploi- improvements, particularly fencing and better water tative use, and to utilize those aspects that distribution, permit animal control. The concepts accidentally produced benefits and to continue to and terminology vary but the basic tenet is periodic combat negative aspects. heavy use on part of a range unit with rest or deferment on the remainder (Herbel 1974, Stoddart Vegetational management: Manipulative treatments et al. 1975). for increasing livestock forage have been condemned in many wildlife circles as made at the expense of Impacts on deer ofachange from less heavy deer habitat. In fact, earlier programs did tend to and less uniform but continuous livestock use to a be over-sized and single-purpose with the result deferred system could be profound.1 Within-year that very large acreages were changed from one form competition between livestock and deer could be of monotony to another. Thus, huge expanses of eased where portions of the range are rested but mature juniper-pinyon were chained and seeded to available to deer. However, the major impact could crested wheatgrass (A-gropyron cristatwn, A. be alteration of competitive relations among plant desertom) from about 1940 to 1970 (Aro 1975). species affecting composition. Indeed, this is the Similarly, large blocks of sagebrush were plowed or objective of any grazing system over continuous sprayed with herbicides in all western states. or season-long use, namely, to improve range condition (usually interpreted as an increase in Assessments of deer habitat values on projects decreaser grasses and forbs, reduction of increaser that were planned with this as an objective are of invader shrubs). practically nil. The few studies extant are usually examinations of older, single-purpose projects and these studies have often shown conflicting results. '~esearchproposal on "Impacts of specialized For example, deer response to juniper-pinyon chainings grazing systems on multiple-use aspects in the has been both positive (Minnich 1969, Reynolds 1964) Intermountain Region" on file at Utah State and negative (Terrill and Spillett 1975, McCulloch Universicy, Range Science Department, Logan. Utah. 1971), depending upon criteria used in evaluation and location.

The story has been much the same in sagebrush: grass (Anderson 1969, Koehler 1970, Lechenby 1969, Urness 1966) and chaparral types (Biswell et al. 1952,

Mule Deer. Habitat L'lzan~es Resulting from Livcs toc~Practices Depending upon vegetation type and season, the of habitat somewhat although its importance has not opposite effect is possible. Heavy early summer live- been assessed. Harassment, generally, has increased stock use can effectively increase vigor and production in intensity on a broad front and should receive of browse plants valuable as winter forage for mule greater attention as potential factors affecting deer (Jensen et al. 1972, Smith and Doell 1968). herd productivity and mortality. Midsummer to fall usein the same area can negate the benefits when livestock shift heavily to browse as Probably more than any other aspect associated forbs and grasses mature. Importance of livestock with livestock management, predator control has as tools to control succession on game winter ranges changed during the period of immediate concern. I has only recently been investigated. Utah has pur- will defer to later papers on the overall question, chased extensive lands as critical winter range to except to reiterate the ubiquity and effectiveness help offset losses to housing and other developments. of control programs over much of the total mule deer Livestock grazing programs to enhance their value for range through the mid-1960's. Public as well as deer are currently active. private lands were systematically treated over huge areas prior to the toxicant ban in 1972. With- Despite some change, grazing systems have not, drawal of toxic compounds, especially 1080, and in my opinion, imposed a controlling influence on other restrictions on control methods, have created near-term deer numbers over entire regions. Reduc- a storm of controversy within the livestock industry tions in permitted livestock numbers and seasons of especially from sheep producers (Bowns 1976, Howard use have been slow but continuous on many grazing 1974, Davenport et al. 1973, Wagner 1972). The units in the Intermountain Region. Trucking of benefits derived from the controversy are numerous livestock from summer to winter range has reduced studies attempting, finally, to quantify predator fall use of deer winter range in some areas. Efforts impacts on livestock and deer populations. to secure more uniform and proper use have proceeded during the past several decades. All of these factors Disease transmission between livestock and mule tend to suggest an improved range situation for deer deer, with a few exceptions, has seldom been more relative to livestock grazing or, at the least, than a local problem. However, such cases are only slightly changed status. difficult to diagnose on rangelands unless losses are heavy. Die-offs in mule deer are rare aside Other livestock practices: Development and from late winter losses where concentrations on poor better distribution of water sources on arid range- condition ranges occur. The disease indicated in lands have permitted yearlong use of ranges to deer such situations is usually "hollow-belly." A sparse that otherwise would be seasonally unusable (Wright literature related to mule deer either means 1959). Deer access to livestock water developments diseases are much less common than in wiiite-tailed should be assured on public lands. Wherever possible. and black-tailed deer, or that less research effort these should be dependable sources, not just available has been expended (Hunter and Yeager 1956, Neiland when livestock are present. The tendency to use and Dukeminier 1972). In either case, no apparent access to water as a means of controlling livestock increases in disease incidence have been reported use in lieu of fencing can have adverse effects on over entire regions in recent years. Furthermore, deer habitat use. It is not a widespread practice it is unlikely that diseases would seriously affect on public lands and it should be discouraged. In deer while elk, on the same ranges, have increased. general, arid lands where water limits seasonal deer use seldom are highly productive habitats. Such Conclusions areas are not extensive and the water supply situation has not changed materially in recent years or it Factors associated with livestock production has improved. on western rangelands that also serve as mule deer habitats have, with the possible exception of Fencing for livestock control, if improperly predator control and increased human activity, constructed, can interfere with deer migrations and changed comparatively little in the past decade. access to habitat. Except for major highway fences, Indeed, some aspects such as reduced livestock use these situations are usually local in nature and on many key areas, changes in class of livestock, normally do not constitute a serious threat to deer and more carefully executed vegetation control as they have with antelope. projects, should have affected deer positively. Therefore, while it cannot be stated with absolute Greater use of vehicles in livestock management certainty, I will go on record as believing that has expanded access roads into more areas in recent livestock grazing practices have had little years. This, plus the accelerated recreational use influence on the general decline in mule deer of rangelands has probably affected seasonal deer use numbers since the mid-1960's.

Mute Deer Habitat Changes Resulting from Livestock Practices Figure 1. Approximate distribution of deer (Odocoileus hemionus) in North America after K.D. Taber (1966) and E. Beltran (1953).

125 - UTAH: Mule Deer Harvest 1000's

100

50-

1935 1945 1955 1965 1975

Figure 2. Harvest curves for mule deer in Utah averaged for the preceding five years. Actual harvests are plotted for 1971-75. UTAH: range stock

- sheep -r WIII. 1,000,000'8

Figure 3. Range cattle and sheep numbers in Utah, January 1 inventories (ARS, Reporting Service). Figure 4. Woody plant increases on desert grassland range at Santa Rita Experimental Range, Arizona (A. taken in 1903, B. retaken in 1948, courtesy of S.C. Martin). Figure 5. Downslope invasion of grassland by pinyon and juniper provides cover value for mule deer in early and mid-succes~ional phases (Photo supplied by R.J. Tauech). Figure 6. "We constantly change the world, even by our inaction; therefore, let us change it responsibly. " B. Franklin. Figure 7. Removal of growing season livestock use can result in successional change affecting deer carrying capacity on sagebrush: bunchgrass winter range (Right of fence grazed by cattle in spring, left area ungrazed by livestock for approximately 30 years, photograph supplied by A.D. Smith). LITERATURE CITED Cronemiller, F. P., and P. S. Bartholomew. 1950. The California mule deer in chaparral forest. Anderson, E. A. 1969. 2,4-D, sagebrush, and mule Calif. F. & G. 3(4):343-365. deer-cattle use of upper winter range. Colo. Game, Fish and Parks Spec. Report. 21. 21 pp. Croxen, F. W. 1926. History of grazing on Tonto. Tonto Grazing Conf., Phoenix, Arizona. 19 pp. Arnold, L. N. 1942. Notes on the life history of the sand pocket mouse. Jour. Mamm. 23(3): Darlington, H. T. 1915. A study of grazing conditions 339-341. in the Wenaha National Forest. Wash. State Agr. Exp. Stn. Bull. 122:l-18. Aro, R. S. 1975. Pinyon-juniper woodland manipulation with mechanical methods. Proc. Symp. Davenport, J. W., J. E. Bowns, and J. P. Workman. 1973. on the Pinyon-Juniper Ecosystem, Logan, Utah. Assessment of sheep losses to coyotes-a problem pp. 67-75. to Utah sheepmen-a concern of Utah researchers. Utah State Univ., Agr. Exp. Stn. Res. Report. Beltran, Enrique. 1953. Vida silvestre y recursos 7. 17 pp. naturales a lo largo de la carretera panamericana. Instituto Mexicano De Recursos Dwyer, D. D. 1975. Response of livestock forage to Naturales Renovables, A. C., Mexico, D.F. manipulation of the pinyon-juntper ecosystem. 228 pp. Proc. Symp. of the Pinyon-Juniper Ecosystem, Logan, Utah. pp. 97-103. Bentley, H. L. 1898. Cattle ranges of the Southwest, a history of the exhaustion of the pasturage Ellison, L. 1954. Subalpine vegetation of the and suggestions for its restoration. U.S.D.A. Wasatch Plateau, Utah. Ecol. Monogr. 24:89-184. Fanner's Bull. 72:l-32. Ellison, L. 1960. Influence of grazing on plant Biswell, H. H., R. D. Taber, D. W. Hedrick, and A. M. succession on rangelands. Bot. Rev. 26(1):1-78. Schultz. 1952. Management of chamise brushland for game in the north coast region of California. Ellison, L., A. R. Croft, and R. W. Bailey. 1951. Calif. F. & G. 38:453-484. Indicators of condition and trend on high range-watersheds of the Intermountain Region. Blackburn, W. H., and P. T. Tueller. 1970. Pinyon U.S.D.A., Agr. Handb. 19. 66 pp. and juniper invasion in black sagebrush communities in east-central Nevada. Ecol. Forest Service. 1973. Pinyon-juniper chaining 51(5):841-848. program on National Forest lands in the state of Utah. U.S.D.A. For. Serv., Interm. Region, Blaisdell, J. P. 1953. Ecological effects of Final Environmental Statement. 60 pp (plus planned burning of sagebrush:grass range on appended materials). the Upper Snake River Plains. U.S.D.A. Tech. Bull. 1075. 39 pp. Forsling, C. L. 1931. A study of the influence of herbaceous plant cover on surface runoff and Blydenstein, J., C. R. Hungerford, G. I. Day, and R. soil erosion in relation to grazing on the R. Humphrey. 1957. Effect of domestic livestock Wasatch Plateau in Utah. U.S.D.A. Tech. Bull. exclusion on vegetation in the Sonoran Desert. 220. 71 pp. Ecol. 38(3) :522-526. Frischknecht, N. C. 1975. Native faunal relation- Bowns, J. E. 1976. Field criteria for predator ships within the P-J ecosystem. Proc. Symp. damage assessment. Utah Science 37(1):26-30. of the Pinyon-Juniper Ecosystem, Logan, Utah. pp. 55-65. Branscomb, B. L. 1958. Shrub invasion of a southern New Mexico desert grassland range. J. Range Glendening, G. E. 1952. Some quantiative data on the Manage. 11(3) :129-133. increases of mesquite and cactus on a desert grassland range in southern Arizona. Ecol. Brown, A. L. 1950. Shrub invasion of southern 33(3):319-328. Arizona desert grassland. J. Range Manage. 3(3) :172-177. Griffiths, D. 1902. Forage conditions in the northern border of the Great Basin. U.S.D.A. Buechner, H. K. 1944. The range vegetation of Kerr Bur. Plant Ind. Bull. 15. 60 pp. County, Texas, in relation to livestock and white-tailed deer. Amer. Midl. Nat. 31:697-743. Griffiths, D. 1903. Forage conditions and problems in eastern Washington, eastern Oregon, north- Bureau of Land Management. 1974. Effects of livestock eastern California, and northern Nevada. grazing on wildlife, watershed, recreation, and Bur. Plant Ind. Bull. 38. 52 pp. other resource values in Nevada. Mimeo. Griffiths, D. 1910. A protected stock range in Cottam, W. P., and F. R. Evans. 1945. A composition Arizona. U.S.D.A. Bur. Plant Ind. Bull. 177. study of the vegetation of grazed and ungrazed 28 PP. canyons of the Wasatch range, Utah. ~coi. 26(2):171-181.

MuZe Deer Habitat Changes Resulting from Livestock Practices Herbel, C. H. 1974. A review of research related Leege, T. A. 1969. Burning sera1 brush ranges for to development of grazing systems on native big game in northern Idaho. Trans. N. her. ranges of the western United States: In: Wildl. Conf. 34:429-438. Plant morphogenesis as the basis for scientific management of range resources. Proc. Workshop Leopold, A. 1924. Grass, brush, timber, and fire of U.S.-Austral. Rangelands Pancl, Berkeley, in southern Arizona. J. For. 22(6):1-10. Calif. U.S.D.A. Misc. Publ. 1271. pp. 138-149. Leopold, A., L. K. Sowls, and D. L. Spencer. 1947. Hines, W. W. 1973. Black-tailed deer populations A survey of over-populated deer ranges in the and Douglas-fir reforestation in the Tillamook United States. J. Wildl. Manage. 11(2):162-177. Burn, Oregon. Oregon Game Comm. Res. Report 3. 59pp. Leopold, A. S. 1950. Deer in relation to plant successions. J. For. 48(10):675-678. Howard, N. E. 1974. The biology of predator control. Addison-Wesley Module in Biology 11. Loope, L. L., and G. E. Gruell. 1973. The ecological 48 PP. role of fire in the Jackson Hole area, north- western Wyoming. Quaternary Res. 3(3):423-443. Hull, A. C., Jr. and M. K. Hull. 1974. Presettlement vegetation of Cache Valley, Utah, and Idaho. Longhurst. W. M., A. S. Leopold, and R. F. Dasnann. J. Range Manage. 27(1):27-29. 1952. A survey of California deer herds. their ranges and management problems. Calif. F. & G. Humphrey, R. R. 1943. A history of range use and Bull. 6. 136 pp. its relation to soil and water losses on the Walla Walla River Watershed. N. W. Sci. 17 Lyon, L. J. 1966. Problems of habitat management (4) : 82-87. for deer and elk in the northern forests. U.S.D.A., For. Serv., Interm. For. 6 Range Humphrey, R. R. 1953. The desert grassland, past Exp. Stn. Res. Paper INT-24. 15 pp. and present. J. Range Manage. 6(3):159-164. Lyon, L. J. 1971. Vegetal development following Humphrey, R. R. 1958. The desert grassland, a prescribed hurning of Douglas fir in south- history of vegetational change and an analysis central Idaho. U.S.D.A., For Serv., Interm. of causes. Bot. Rev. 24:193-252. For. & Range Exp. Stn. Res. Paper INT-105. 30 PP. Hunter, G. N., and L. E. Yeager. 1956. Management of the mule deer. In: The deer of North McConnell, B. R., and P. D. Dalke. 1960. The America, W. P. ~a~lz,ed. The Stackpole Co., Cassia deer herd of southern Idaho. J. Wildl. Harrisburg, PA. pp. 449-482. Manage. 24(3) :265-271.

Jensen, C. H., A. D. Smith, and G. W. Scotter. 1972. McCulloch, C. Y. 1973. Control of pinyon-juniper Guidelines for grazing sheep on rangelands used as a deer management measure in Arizona. by big game in winter. J. Range Manage. 25(5): Ariz. Game & Fish Dept., Fed. Aid Project 346-352. W-78-R, WP 4, Jobs 2 and 7. 32 pp.

Julander, 0. 1962. Range management in relation to Minnich, D. W. 1969. Vegetative response and mule deer habitat and deer productivity in Utah. pattern of deer use following chaining of J. Range Manage. 15(5):278-281. pinyon and juniper forest. Colo. Game, Fisb, & Parks. Mimeo. Kennedy, P. B. 1901. A preliminary report on the summer ranges of western Nevada sheep. Nev. Mueggler, W. F. 1950. Effects of spring and fall Agr. Exp. Stn. Bull. 51. 64 pp. sheep grazing on vegetation of the Upper Snake River Plains. 3. Range Manage. 3(4):308- Kennedy, P. B. 1903. Summer ranges of eastern 315. Nevada sheep. Nev. Agr. Exp. Stan. Bull. 55. 55 PP. Neiland, K. A., and C. Tlukeminier. 1972. A bibliography of the parasites, diseases, and Koehler, 9. A. 1970. A review of literature on re- disorders of several important wild ruminants seeding sagebrush-bunchgrass ranges in the semi- of the northern hemisphere. Alaska Dept. arid western United States. Oregon Game Corn., Fisb & Game Wildl. Tech. Bull. 3. 151 pp. Fed. Aid Project W-53-R-12, Job. 1. 103 pp. Pase, C. P., P. A. Ingebo, E. A. Davis, and C. Y. Koehler, D. A., and D. A. Lechenby. 1970. Economics McCulloch. 1967. Improving water yield and of range reseeding vs. feeding of mule deer. game habitat by chemical control of chaparral. Oregon Game Corn., Fed. Aid Project W-53-R-12, Intern. Union of Forestry Res. Org. Congress, Job. 1. 14 pp. (Special report). Munich, Germany. 14:463-486. (Papers Section 01-02-11). LeMarch, V. C. 1974. Paleo-climatic inferences from long tree-ring records. Science 183:1043- Phillips, F. J. 1910. The dissemination of junipers 1048. by birds. For. Quart. pp. 60-73.

Lechenby, D. A. 1969. Ecological study of mule deer. Oregon State Game Comm., Fed. Aid Proj. W-53-R-11. Job 1. 51 pp.

33 Mule Deer Habitat Changes ResuZting from Livestock Practices Pickford, G. D. 1931. The in'luence of continued Smith, A. D., and D. D. Doell. 1968. Guides to heavy grazing and of promiscuous burning on allocating forage between cattle and big game spring-fall ranges in Utah. Ecol. 13(2): on big game winter range. Utah Div. Fish & 159-171. Game Publ. 68-11. 32 pp.

Plummer, A. P., D. R. Christensen, and S. B. Monson. Stoddart, L. A. 1941. The Palouse grassland 1968. Restoring big-game range in Utah. association in northern Utah. Ecol. 22 (2) : 158- Utah Div. Fish & Game Publ. 68-3. 183 pp. 163.

Reynolds, H. G. 1950. Relation of kangaroo rats Stoddart, L. A., and A. D. Smith. 1955. Livestock to range vegetation in southern Arizona. grazing in the Intermountain Region. Agr. and Ecol. 31(3):456-463. Food Chem. 3(4) : 303-305.

Reynolds, H. G. 1964. Elk and deer habitat use of Stoddart, L. A., A. D. Smith, and T. W. Box. 1975. pinyon-juniper woodlands in southern New Range Management. McGraw-Hill, Inc. 532 pp. Mexico. Trans. N. Amer. Wildl. Conf. 29:438-445. Swank, W. G. 1958. The mule deer in Arizona chaparral. Ariz. G. & F. Dept. Wildl. Bull. 3. 109 pp. Reynolds, H. G., and J. W. Bohning. 1956. Effects of burning on a desert grass-shrub range in Taber, R. D. 1966. Land use and native cervid southern Arizona. Ecol. 37(4):769-777. populations in America north of Mexico. Univ. Montana For. and Cons. Exp. Stn. Bull. 29, pp. Reynolds, H. G. and G. E. Glendening. 1949. Merriam 201-225. (Reprint from Intern. Union of Game kangaroo rat, a factor in mesquite propagation Biol., Trans. VI Congress, Bournemouth, on southern Arizona rangelands. J. Range Manage. England, Oct. 7-12, 1963). 2(4) :193-197. Taber, R. D., and R. F. Dasman. 1958. The black- Reynolds, 11. G., and S. C. Martin. 1968. Managing tailed deer of the chaparral. Calif. F. & G. grass-shrub cattle ranges in the Southwest. Dept. Game Bull. 8. 163 pp. U.S.D.A., Agr. Handb. 162. 44 pp. Tausch, R. J. 1973. Plant succession and mule Reynolds, R. V. R. 1911. Grazing and floods: a deer utilization on pinyon-juniper chainings study of conditions in the Manti National in Nevada. Univ. Nevada M.S. thesis, Reno. Forest, Utah. U.S.D.A., For. Serv. Bull. 91. 150 pp. 16 PP. Terrill, T. L., and J. J. Spillett. 1975. Pinyon- Robertson, J. H. 1971. Changes on a sagebrush-grass juniper conversion: its impacts on mule deer range in Nevada ungrazed for 30 years. J. and other wildlife. Proc. Symp. of the Pinyon- Range Manage. 24(5):397-400. Juniper Ecosystem, Logan, Utah. pp. 105-119.

Sampson, A. W. 1944. Plant succession on burned Thornber, J. J. 1910. The grazing ranges of Arizona. chaparral lands in northern California. Univ. Univ. Ariz., Agr. Exp. Stn. Bull. 65. pp. Calif. Agr. Exp. Stn. Bull. 685. 143 pp. 245-360.

Sampson, A. W., and B. S. Jesperson. 1963. Timmons, F. L. 1942. The dissemination of prickly- California range brushlands and browse plants. pear seed by jackrabbits. Jour. Am. Soc. Univ. Calif. Agr. Exp. Stn. Manual 33. 162 pp. Agron. 34(6):513-520.

Sampson, A. W., and L. H. Neyl. 1918. Range Tueller, P. T. 1973. Secondary succession, disclimax, preservation and its relation to erosion control and range condition standards in desert shrub on western grazing lands. U.S.D.A. Bull. 675. vegetation. In: Arid Shrublands, Proc. 35 PP. Workshop of the U.S.-Austra. Rangelands Panel 3: 57-65. Schulman, E. 1956. Dendroclimatic changes in semi- arid America. Univ. Ariz. Press, Tucson. 142 pp. Tueller, P. T.,and W. H. Blackburn. 1974. Condition and trend of the big sagebrushlneedle-and-thread Shantz, H. L. 1947. Fire as a tool in the manage- grass habitat-type in Nevada. J. Range Manage. ment of the brush ranges in California. Calif. 27(1) :36-40. Dept. Nat. Resources, Div. of For., Sacramento. 156 pp. Umess, P. J. 1966. Influence of range improvement practices on composition, production, and Smith, A. D. 1949. Effects of mule deer and utilization of Artemisia deer winter range in livestock upon a foothill range in northern Utah. central Oregon. Oregon State Univ. Ph.D. J. Wildl. Manage. 13(4):421-423. dissertation. 183 pp.

Smith, A. D. 1958. Considerations affecting the Umess, P. J. 1975. Deer use changes after root place of big game on western ranges. Proc. Soc. plowing in Arizona chaparral. U.S.D.A. For. Amer. For., Salt Lake City, Utah. pp. 188-192. Serv., Rocky Mt. For. & Range Exp. Stn. Res. Note RM-255. 8 pp. Smith, A. D. 1959. Whose space and for what? Trans. N. Amer. Wildl. Conf. 24:449-456.

MuLe Deer Habitat Changes Resulting from Livestock Practices Wagner, F. H. 1972. Coyotes and sheep, some Whitfield, C. J., and H. L. Anderson. 1938. thoughts on ecology, economics, and ethics. Secondary succession in the desert plains Utah State Univ.. Honor Lecture 44:l-59. grassland. Ecol. 19(2) :171-180.

West, N. E., K. H. Rea, and R. J. Tausch. 1975. Wooten, E. 0. 1908. The range problem in New Mexico Basic synecological relationships in pinyon- N. Mex. Agr. Exp. Stn. Bull. 66. 46 pp. juniper woodlands. Proc. Symp. on the Pinyon-Juniper Ecosystem, Logan, Utah. Wooten, E. 0. 1915. Factors affecting range manage- pp. 41-53. ment in New Mexico. U.S.D.A. Bull. 211. 39 pp. Wright, J. T. 1959. Desert Wildlife. Ariz. Game 6 Fish Dept. Wildl. Bull. 6. 78 pp.

35 MuZe Deer Habitat Chmges Resulting frm Livestock Practices ALTERATION OF IRnE DEER HABITAT BY WILDFIRE,

LOGGING, HIGHWAYS, AGRICULTURE, AND HOUSING DEVELOPMENTS

Olof C. Wallmo Principal Wildlife Biologist Rocky Mountain Forest and Range Experiment Station U.S.D.A. Forest Service Fort Collins, Colorado 80521

Dale F. Reed Vildlife Researcher Colorado Division of Wildlife Glenwood Springs, Colorado 81601

Len H. Carpenter Assistant Wildlife Researcher Colorado Division of Wildlife Kremling, Colorado 80459

Abstract

The meager data available fail to support the hypothesis that forest fires, logging, highways, housing developments, or agriculture, singly or in combination, can be held responsible for a decline in the population of mule deer (OdocoiZeus hemiom hemionus) throughout the western United States. If posed, it would be a vacu- ous hypothesis in the absence of documentation of such a decline. A uniform resource inventory system clearly is needed. The Forest and Rangeland Renewable Resources Planning Act may provide the opportunity to develop such a systen.

The geographic range of the Rocky Mountain mule change are assumed to be causative, and the casual deer (OdocoiZeus hemionus hemionus) covers more than mechanisms can only be postulated. They might be 1 million square miles of the United States. Con- proven with acceptable levels of confidence after sidering the enormous ecological amplitude of the the hypothesis is posed, but not in the process of species, it can be presumed that at one time or hypothesizing. another in history most of this range was habitable to some extent. That is, it was poor, mediocre, or Today we are in the position of posing hypo- good mule deer habitat, but probably never static. theses. Managers are concerned over the contentions During the time since the species appeared and dif- that mule deer populations are declining over the ferentiated into 11 recognized subspecies, the contin- entire range and that some common cause or combin- ent has undergone great changes in climates and floras. ation of causes is behind it. To venture into this position it is necessary first to document the pop- A dynamic system would be necessary to classify ulation change in magnitude and location. Unfortun- mule deer habitat over time. It would detect the ately our knowledge of the history of mule deer influences of epochal changes, lesser climatic fluc- populations on a continental scale is based only on tuations resulting from irregular behavior of the sun, guesses derived, commonly second- or third-hand, and, on a still smaller scale, the unpredictable from subjective impressions. By that means Seton droughts, pluvials, and prolonged winters that are (1937) guessed that there were about 10 million mule superimposed on larger climatic trends. With that deer in North America at the time of the arrival of capability, perhaps it would also be able to distin- white men and about one-half million in 1908. Two guish from "natural" habitat trends those effects that decades later there were supposed, on equally poor are imposed by man. Without such a system, we can evidence, to be 100,000 mule deer on the Kaibab only say for sure that habitat conditions are in a National Forest alone (Caughley 1970), an area com- transition state that we may or may not be modifying prising less than 0.1 percent of the range of the significantly. To maintain them in some constant species. state presumes that we understand that state and the forces changing it. The only consistent reports of deer numbers on a nation-wide basis are provided by the U.S. Forest Commonly, the evidence for habitat change is Service. If these estimates are to be believed, taken to be the increase or decrease in the popula- there were about 750,000 deer (all species) on the tions of the species in question. Observed changes in western National Forests in 1930, over 3 million in the environment that correlate with the population 1965, and nearly two and one-half million in 1972.

37 Alteration of MuZe Deer Habitat Unfortunately, these figures are not derived from sys- The U.S. Forest Service has maintained a thor- tematic inventories. Nor have the states and provin- ough fire reporting system since 1909. Data on area ces of the U.S. and Canada provided a credible body of burned within the National Forest boundaries in data from which to infer population trends. Conse- Region 1, the northern Rocky Mountains, and Region 2, quently, we are on flimsy ground in tracing events central Rocky Mountains, are presented in Table 1. that may have had large effects on mule deer In the 3 decades from 1910 to 1940 over 7 million populations. acres were affected by forest fire. In the 3 decades from 1940 to 1970 less than 1 million acres were We do not suggest that the phenomena discussed burned. below are casually related to changes in deer numbers on a region-wide basis. It may be productive to The habitat improvement that may result from consider them, though, if for no other reason than to fire results from disclimax ecological succession. emphasize the need for better information. Five types Though the literature on post-fire development of of habitat alteration are discussed: fire, logging, vegetation is extensive, the duration of conditions roads and highways, agricultural development, and more favorable to deer is not well documented. Lyon housing development. (1971) suggests that the benefits would continue for up to 60 years in the Douglas fir (Pseudotsuga spp.) type in southcentral Idaho. In Wyoming, the advan- tages may be lost in 10-20 years in lodgepole pine FIRE (Pinus eontorta) stands, 20-50 years in aspen (PopuZus tremui-oides), 50 years in Douglas fir, and It is widely accepted that forest fires generally 80 years in subalpine fir (Abies Zasioearpa) (U.S. improve the quality of mule deer habitat. Lyon and Department of the Interior 1974). Patton and Avant Stickney (1966) stated that "most of the big-game (1970) estimate that burning aspen stands in New ranges of western Montana and northern Idaho were Mexico will improve the habitat for big game for 8 to created by uncontrolled forest fires" -- principally 10 years. between 1910 and 1934. The term creation might be too strong, inasmuch as the deer lived there prior to the Whatever the period of effect, it must be con- fires, but the habitat still may have been improved. sidered in estimating the area potentially influen- Post-fire increase in the biomass of vegetation cing deer habitat over time. If an average period of accessible as deer forage is a rational basis for 20 years is realistic, in the National Forests of the assuming habitat improvement. A chain of reasoning central Rocky Mountain Region (Region 2) there were can be constructed to support the hypothesis that some 450,000 acres in "improved" condition in 1929 larger deer populations would result. But none of the and 150,000 in 1970 (Fig. 1). If the improved information available to date demonstrates that it has condition lasted an average of 40 years the occurred. peak area enhanced would have been about 7.4 million acres in 1950, dwindling to about 1.2 in 1975; a max- While some authors (Pengelly 1963; Lyon and imum of about 2 percent and a minimum of about 0.4 Stickney 1966) contend that forest fires have had a percent of the total area which the fire reports dominant influence on deer populations in the Rocky cover. It seems questionable, at least, that the Mountains, others (Edwards 1956; Picton and Knight difference between these fractions of the total area 1969; Robinette et al. 1952; Wallmo and Gill 1971) could have influenced regional deer populations to a suggest that snow depth and duration on winter range detectable degree, particularly in view of the fact are a major determinant of population levels. At the that we have little evidence to support the belief same time we are led to believe that changes in hunt- that forested summer range is deficient in its ing pressure since white man settled the West may have unburned state . effected major changes in deer numbers. Whatever correlations we might discover between the histories of forest fires and deer populations, they must be considered in the light of other factors.

Table 1. Acres burned by decades within protective boundaries of Iiational Forests and Grasslands of Regions 1 and 2 of the U.S. Forest Service.

Years - Region 1 Region 2 Total

I' Data incomplete. 2' Data not available.

Alteration of Mule Deer Habitat 38 Fig. 1. Acres presumably in "improved" condition for deer range as a result of fire in National Forests of the central Rocky Mountain Region (relative to a base status in 1910). LOGGING ROADS AND HIGHWAYS i

In forest environments understory vegetation bio- It is indisputable that deer are killed in col- mass is inversely related to overstory. This is an lisions with high-speed motor vehicles. Beyond that, acceptable generalization for most forest types in the impacts of roads and highways on western-wide Noith America (Ffolliott and Clary 1972). Thus, vir- mule deer numbers are not well understood. Indirect tually all timber removal operations could, impacts would include, first, the physical loss of theoretically, benefit deer habitat, the maximum bene- some natural habitat including forage, water, and fit potentially coming from clearcutting (Wallmo et al. cover (Leo~old1951), requiring adjustments by winter- 1972). Pengelly (1963) inferred, ambiguously, that ing and migrating deer. Secondly, traffic and road- logging in the northern Rocky Mountains was a major ways present auditory and visual barriers which can factor influencing the increase in deer populations in conceivably adversely affect deer behavior. that region in the first half of this century. Increases in deer populations in the region, specifi- Loss of habitat - Reasonably accurate estimates cally as a result of logging have yet to be Jocumented, of the number of acres of habitat directly replaced however. by roads and highway surfaces or lost through removal of native vegetation in rights-of-way are not readily Research on the subject indicates that use by deer available. Thus, we made projections for Colorado to commonly increases after logging (Edgerton 1972; Patton serve as an example of the potential magnitude of 1974; Pearson 1968; Wallmo 1969). But Regelin et a]. mule deer habitat losses from roads and highways (1974) postulated that other factors kept mule deer (Table 2). Interstate, rural, and county highways populations in the central Rocky Mountains well below usurp about 45, 12, and 7 acres of land per mile, the densities that could be supported by unlogged respectively. Total projected acres encompassed by forest. Nevertheless, the circumstantial evidence interstate, rural, and county highways increased that logging can be beneficial to mule deer habitat 42.7, 7.5, and 4.8 percent, respectively, between justifies consideration of its potential effect on a 1960 and 1974. Consequently, interstate highways regional basis. Wallmo et al. (1972) estimated that represent the type of roadway with the greatest poten- clearcutting in subalpine forests of the central Rocky tial impact on mule deer habitat. In mountainous Mountains increased deer forage supplies nearly 50 per- areas of western Colorado most highways are aligned cent 15 years and 20 years (the latter unpublished) along valleys and water courses, frequently on south- after logging. facing slopes for ease of winter naintenance These are specific cases where important acres of deer Data on timber removals for the entire Rocky Moun- winter range are modified and migration routes severed tain area were not obtained, but complete records from or impacted. the National Forests of the Central Rocky Mountain Region (Region 2) were examined. Over the period of In most cases, highway rights-of-way are revege- record, 1911 to date, there has been a progressive tated with grass or grass-legume mixtures, with increase in the timber harvest, reaching a peak in crested wheatgrass (Agropyron spp.) being one of the 1969. A slight decrease since then is attributable to more popular species (Reynolds and Springfield 1953). the public opposition to clearcutting and the develop- It is highly palatable in the "early green-up" period ment of environmentally preferable harvesting systems (Narch-April) and is implicated in much of the spring by Forest Service silviculturists. deer mortality on highways. These accidents, pius those occurring during winter and migration periods, In Region 2 the total area logged by all harvest- account for most of the mule and black-tailed deer ing methods has averaged over 65,000 acres per year (C. hemionus) killed from collisions with vehicles over the past decade, compared with an average of about in the western states (Table 3). 6,000 acres burned. In Region 1 (northern Rocky Moun- tains) over 100,000 acres per year are logged (Lyon Most of the states do not have accurate figures 1969), compared with an average of about 20,000 acres on road kills because it is difficult to routinely burned. monitor all federal, state, and county roads and because animals which escape the rights-of-way before As with fire, the beneficial effects of logging to dying usually are not found. Irrespective of their deer habitat can be presumed to last over a period of accuracy, the estimates in Table 3 represent definite years (Wallmo et al. 1972). If we assumed an influence losses of deer. We specifically avoid drawing infer- lasting 20 years, we could estinate the region-wide ences from the sums of 16,896 in 1967 and 18,822 in cumulative effect of logging (Fig. 2) as we did with 1974. They might represent increased mortality from fire. The results suggest that the decreasing amount smaller populations, or decreased mortality from of fire-influenced habitat in the central Kocky Moun- larger populations. tains in the past 40 years is more than compensated for by logging-influenced habitat. Together they remain a The number of deer killed on any given section very small fraction of the total area considered. of highway is related closely to two parameters, the number of deer coming onto or crossing the traveled Assuming that fire and logging have similar portion of highway and the traffic volume. High num- effects on deer habitat, the record does not substanti- bers of deer crossings combined with high traffic ate that their combined effect could account for de- volume result in "critical" deer kill areas. For creasing deer populations in the central and northern example, Colorado Highway 82, a 4-lane, high traffic Rocky Mountains. volume (Fig. 3) highway, had an annual traffic volume of over 2 million vehicles (5,628 vehicles per day) in 1975, an increase of 79.7 percent since 1968. Three "critical" kill areas existed in a 15-mile length of Highway 82 where methods (Reed and Woodard

AZteration of Mule Deer Habitat YEARS

Fig. 2. Acres presumably in "improved" condition for deer range as a result of logging in National Forests of the central Rocky Mountain Region (relative to a base status in 1910). YEAR

Fig. 3. Annual traffic volume on Colorado Highway 82 from 1968 through 1975. i07fr; Pojar et al. 1975) have been used to reduce AGRICULTURAL DEVELOPMENTS deer-vehicle accidents. Since some of these methods restrict deer movements, they also reduce the amount Linsdale and Tomich (1957:287) stated "Mule of available habitat. deer are more strictly mountain animals than they were in primitive conditions, mainly because of the Traffic and road-way barriers -- The behavioral removal of woody vegetation from the flat lowlands response of ungulates to traffic stimuli may be either by human cultivation and other use of the soil." a survival advantage or disadvantage. Habituation This may be a questionable generalization in face of (Thorpe 1963; Geist 1971) enables most ungulates to the eastward expansion of mule deer in the prairies, use ranges within visual and auditory range of roads but it is reasonable to believe that agriculture and highways. Klein (1971) reported that traffic grossly alters the character of mule deer habitat. along highways did not appear to disturb reindeer The net result probably varies with the extent of (Rangifer tarandus) feeding or moving nearby. Grenier cultivation, the location, and the crops. Conse- (1974) reported on moose (AZces alces) movement and quently, attempting to correlate changes in mule mortality on roads where habituation to traffic deer numbers with the history of agricultural devel- stimuli apparently occurred. Altmann (1952) indi- opment is hazardous at best. cated that elk (Cervus canadensis nelson$) became conditioned to the sight and sound of passing cars. The available historical records of agricul- She observed a cow elk move her calf off a paved road tural development offer little information relative by walking back and forth, around it, and eventually to mule deer habitat. Certain national and regional pushing it sideways. More recently, Ward et al. data are reviewed here along with data from Colorado (1973) reported that elk showed little aversion to that can be related more specifically to mule deer. traffic within 300 yards of an interstate highway, where noise reached 58 decibels. Carbaugh et al. Availability of irrigation water has made crop (1975) found that grazing, lying, walking, or running production possible on many soils of the western were exhibited extensively by white-tailed deer U.S. that were previously unsuitable for agricul- (0. virginianus) along Interstate 80 in Pennsylvania. tural development. Irrigated land on farms through- Reed et al. (1975) reported on Rocky Mountain mule out the U.S. totaled more than 37 million acres in deer behavioral responses to a concrete-box underpass 1964 (National Academy of Sciences 1970). The 17 under Interstate 70 in western Colorado. When indi- western states accounted for more than 33 million viduals or groups of deer were observed near the acres. Nationwide, land under irrigation in 1970 underpass entrance, 50 to 100 feet from the west- was increasing at the rate of 780,000 acres annually. bound highway lanes, the passing of only 7.3 percent and during the period 1949 to 1964, western states of 449 vehicles traveling west caused some flight accounted for 80 percent of the increase (National reaction or escape behavior (as defined by Hediger Academy of Sciences 1970). If this trend continued, 1950; Scott 1958). These observations support a by 1976 there would have been over 40 million acres hypothesis that ungulates, particularly mule deer, of irrigated land in the western U.S. habituate to the sight and sound of traffic. Although there has been a steady increase in Others have reported some reluctance in ungu- irrigation, much of the land was already in crop lates to approach or cross highways. In Glacier production, particularly in the more humid eastern National Park mountain goats (Oreamnos americanus) U.S. However, much of the increase in land irri- often hesitated in cover or on the pavement edge, and gated between 1950 and 1965 in the 17 western states walked stiff-legged or ran across the highway (Singer also comprised land previously cultivated under dry- 1975). Ward et al. (1973) indicated that a highway land conditions. In the most arid states (New acted as a barrier to elk movement. Behrend and Mexico, Arizona, Utah, and Nevada) the irrigated Lubeck (1968) provided evidence that white-tailed area increased from 2.7 to 3.0 million acres between deer are more sensitive to disturbance along roads 1950 and 1965 and most of this represented "new" than they are in more removed areas. Villmo cropland (National Academy of Sciences 1970). (1975) suggested that reindeer, which have habituated to roadsides, may still be adversely affected by It is important to note from the standpoint of their proximity. tie hypothesized that reindeer for- mule deer habitat that 51 percent of the irrigated age utilization is decreased along roadways because cropland in the West was used for the production of they interrupt feeding and resting activities each livestock feed (National Academy of Sciences 1970). time an automobile passes. In a study by Rost (1975), Much of this land was pasture, hay lands, or other densities of Rocky Mountain mule deer fecal pellet- nonharvested crops and may have had a different groups increased with distance from roads in two of effect than would the same amount of land irrigated three vegetation types. However, the assumption that for corn production. pellet-group densities are valid measures of habitat use is questionable. The rate of fecal deposition Using Colorado as an example of the western might be affected by many factors (Neff 1968), such states, it is possible to obtain values that relate as psychological stress caused by traffic-associated more specifically to the magnitude of the encroach- stimuli. ment of agricultural development on mule deer habitat. By overlaying maps of mule deer range The combined result of habitat loss and road (Colorado Division of Wildlife) on Colorado's land kills may be of significance to deer populations but use maps prepared by the Colorado Land Use Cormnis- we can cite no quantified examples of the effect. We sion, acres of mule deer range encompassed by irri- can only consider it to be one of the inimical forces gated and nonirrigated cropland were determined. working on mule deer, and one which we are unlikely The land use map was prepared in 1973 but more real- to reverse but only modify with more intensive istically reflected land use in 1971 or 1972. Since management. most of the mule deer in Colorado are found from the

43 Alteration of Mule Deer Habitat ------Table 2. H~lesof Interstate, rural, and county h~ghwaysand projected areas of rlght-of-way In Colorado.

Interstate Rural County Estimated Projected Estimated Projected Estimated Projected Total Year Mileage 11 Acres 21 Mileave Acres 21 Mileage 1/ Acres 4/ Acres

L' Colorado Division of Highways. 1936-1975. Colorado State Highway System route descriptions and mileage statistics. Planning and Research Rep(s). Denver. ., L' Based on 44.6 acres per mile planimetered from aerial photography of Interstate 70 (4-lane divided highway) east of Avon, Colorado. 2! Based on a calculated 12.1 acres per mile, assuming a right-of-way width of 100 feet. Based on a calculated 7.3 acres per mile, assuming a right-of-way width of 60 feet. The decline in mileage was caused by road reclassification and by a declining rural population which led to decreased rural road use and a decline in the number of miles of road maintained.

Table 3. Estimated number of mule and black-tailed deer (OdocoiZeus hemionus) killed from collisions with vehicles in the western U.S.

-State Arizona California Colorado ldaho Montana Nevada New Mexico Oregon Utah Washington Wyoming ----- Totals 16,896 11,047 12,098 12,647 12,992 14,323 13,350 18,822

L' Thompson, F. A. 1968. Deer on highways. 1967 supplement. New Mexico Dept. Game and Fish. Sante Fe. 6 PP. 2/ Arizona Game and Fish Department. 1969. Wildlife Newsletter 3(50):1. (Mule deer only) 31 Garland, L. E. (No date). Number of deer lost to causes other than hunting - 1969. Vermont Dept. Fish and Game, Roxbury. 1 p. Estimates based on fiscal year (1 Jul-30 Jun) tabulations (Per. corn. G. Gates, New Mexico Dept. Fish and Game, Santa Fe). Per. comm. R. Drobnick, Utah Div. Wildl. Resour., Salt Lake City. 6/ Per. corn. D. Strickland, Wyoming Game and Fish Dept., Cheyenne.

AZteration of MuZe Deer Habitat front range of the Rocky Mountains westward, the mule habitat change over time, we will be in a better deer range in the eastern plains of Colorado was not position to assess the impacts on deer populations. included in the comparison. Perhaps the most important message of this Of 64,192 mi2 of mule deer range, 3,706 mi2 (5.8 paper is that man keeps poor records of the vicis- percent) were in irrigated cropland. An additional situdes of his environment. We have no systems for 685 nt2 (1.1 percent) were in nonirrigated cropland. inventorying quantitative changes in the habitats on Much of the irrigated cropland is native and earth, and only rudimentary concepts of their quali- alfalfa hay lands, but considerable acreage is tative significance. It is important that this also involved in orchards and other human food crops. deficiency be overcome, that we employ reliable in- Considering the relatively small areas involved, in formation rather than crude speculation in our relation to total mule deer range, it is difficult to assessment of wildlife habitat on a national scale. believe that agricultural development has materially influenced numbers of mule deer either on local or There is a common interest in this matter, and regional levels. it will be best served through a common effort. A potential vehicle for this purpose is the Forest and Rangeland Renewable Resources Planning Act of 1974 (PL 93-378). It assigns to the U.S. Department of HOUSING DEVELOPMENTS Agriculture, Forest Service, in cooperation with other agencies, the responsibility for a continuing Available records of acreage involved in housing assessment of the renewable natural resources of the developments are practically nonexistent. County U.S. in the following systems: wildlife and fish governments are generally the only source of infor- habitat; outdoor recreation and wilderness; range- mation but summaries of the records are rarely land grazing; timber; land and water; human and com- obtainable. The situation may be improved by the munity development. A first order of business is increasing activity of county and state land use plan- the determination of information needs and the ning commissions. methodology for fulfilling these. A multidisciplin- ary group with this assignment has been assembled in The land use maps prepared by Colorado's Land Use the Rocky Mountain Forest and Range Experiment Commission (1973) indicate that 1,079 square miles Station, headquartered in Fort Collins, Colorado. (1.7 percent) of mule deer range in that State were in The Colorado Division of Wildlife is cooperating in housing developments. This represented only those the development of techniques for monitoring land areas that had been platted and offered for sale and and vegetation attributes related to the quantita- did not include areas under consideration for devel- tive and qualitative adequacy of mule deer habitat. opment. In the western U.S. in general, and in This program will link data from air- and satellite- Colorado specifically, many of these developments have borne surveillance systems to on-the-ground evalu- occurred on wintering areas that are most critical to ation. The results will be built into the national mule deer. This is mostly due to property ownerships, inventory system for all resources, which, hopefully, general topography, and previously located transpor- will take us a respectably large step toward more en- tation and utility corridors. These developments, lightened habitat evolution. with their accompanying increases in automobiles, snowmobiles, other motorized vehicles, dogs, and human activity, affect large areas beyond the actual boun- dary of the specific housing development. As a LITERATURE CITED result, the overall effect of housing developments on mule deer habitat is greater than indicated by anal- Altmann, M. 1952. Social behavior of elk. Cervus ysis of only the actual land area impacted. canadensis netsoni, in the Jackson Hole Area of Wyoming. Behavior 4:116-143. However, if the values obtained for Colorado on extent of housing development are realistic for the Behrend, D. F. and R. A. Lubeck. 1968. Summer whole of mule deer range, it seems improbable that the flight behavior of white-tailed deer in two small amount of deer habitat involved would result in Adirondack forests. J. Wildl. Manage. 32(3): a regional decline in numbers of mule deer. Local 615-618. developments may essentially eliminate deer from limited areas. Unfortunately, we are unable to assess Carbaugh, B., 'J. P. Vaughan, E. D. Bellis, and H. B. the sum of such influence. Graves. 1975. Distribution and activity of white-tailed deer along an interstate highway. J. Wildl. Manage. 39(3):570-581.

DISCUSSION Caughley, G. 1970. Eruption of ungulate populations, with emphasis on Himalayan thar in New Each of the factors discussed -- fire, logging, Zealand. Ecology 51(1):53-72. roads, agricultural aod housing development -- alters the habitat for mule deer in some manner. The effect Edgerton, P. J. 1972. Big game use and habitat of these factors, taken either singly or in combin- changes in a recently logged mixed conifer ation, on numbers of mule deer remains unknown. It is forest in northeastern Oregon. Proc. Annu. difficult to relate cause and effect when neither has Conf. W. Assn. State Game and Fish Comm. 52: been carefully defined and quantified. If we are 239-267. genuinely interested, we must develop uniform data gathering procedures applicable to the entire range Edwards, R. Y. 1956. Snow depths and ungulate abun- of mule deer. When we can describe the magnitude of dance in western Canada. J. Wildl. Manage. 20(2) :159-168.

45 AZteration of Mule Deer Habitat Ffolliott, P. F. and W. P. Clary. 1972. A selected Picton, H. D. and R. R. Knight. 1969. A numerical and annotated bibliography of undersotry- index of winter conditions of use in big game overstory vegetation relationships. Tech. Bull. management. Montana Fish and Game Dept. Spec- 198, Agric. Exp. Sta., University of Arizona, ial Report No. 3, Federal Aid Projects W-74-R Tucson. 33 p. and W-98-R. 8 p. (processed)

Geist. V. 1971. A behavioral approach to the man- Pojar, T. M., R. A. Presence, D. F. Reed, and T. N. agement of wild ungulates. Pages 413-424 in E. Woodard. 1975. Effectiveness of a lighted, Duffey and A. S. Watts, eds. The scientific animated deer crossing sign. J. Wildl. Manage. management of animal and plant communities for 39(1) :87-91. conservation. Eleventh Symp. British Ecol. Soc., Blackwell Scient. Publs., Oxford. 652 p. Reed, D. F. and T. N. Woodard. 1974. Deer-auto accident studies in Colorado. Univ. of Colo- Grenier, P. A. 1974. Orignaux tu4s sur la route dans rado at Denver, Proc. Annu. Highway Conf. 47: le Parc des Laurentides, Quebec, de 1962 a 1972. 66-77. Naturaliste Can. 101(5):737-754. Reed, D. F., T. N. Woodard, and T. M. Pojar. 1975. Hediger, H. 1950. Wild animals in captivity. Behavioral response of mule deer to a highway Butterworth, London. 207 p. underpass. J. Wildl. Manage. 39(2):361-367.

Klein, D. R. 1971. Reaction of reindeer to obstruc- Regelin, W. L., 0. C. Wallmo, J. Nagy, and D. R. tions and disturbances. Science 173(3995):393- Dietz. 1974. Effect of logging on forage 398. values for deer in Colorado. 3. For. 72(5): 282-285. Leopold, A. S., T. Riney, R. McCain, and L. Tevis, Jr. 1951. The Jawbone deer herd. California Reynolds, H. G. and H. W. Springfield. 1953. Re- Dept. Fish and Game, Game Bull. No. 4. 139 p. seeding southwestern range lands with crested wheatgrass. U.S. Dept. of Agriculture, Linsdale, J. M. and P. Q. Tomich. 1953. A herd of Farmers' Bull. 2056. 20 p. mule deer. University of California Press, Berkeley and Los Angeles. 567 p. Robinette, W. L., 0. Julander, J. S. Gashwiler, and J. G. Smith. 1952. Winter mortality of mule Lyon, L. J. 1969. Wildlife habitat research and deer in relation to range condition. J. Wild. fire in the northern Rockies. Proc. Tall Timbers Manage. 16 (3) :289-299. Fire Ecology Conf. 9:213-227. Rost, G. R. 1975. Response of deer and elk to Lyon, L. J. 1971. Vegetal development following roads. M.S. Thesis, Colorado State Univ., Fort prescribed burning of Douglas fir in south- Collins. 51 p. central Idaho. U.S.D.A. Forest Service Res. Paper INT-105. 30 p. Scott, J. P. 1958. Animal behavior. 2nd ed., Univ. of Chicago Press, Chicago. 349 p. Lyon, L. J. and P. F. Stickney. 1966. Two forest fires: and some specific implications in big- Seton, I?. T. 1937. Lives of game animals. Vol. 3. game habitat management. Proc. W. Assn. State Hoofed Animals. Literary Guild of Amer., New Game and Fish Commissioners 46:187-193. York. 780 p.

National Academy of Sciences-National Research Coun- Singer, F. J. 1975. Behavior of mountain goats, cil. 1970. Land use and wildlife resources. elk and other wildlife in relation to U.S. Washington, D.C. 262 p. Highway 2, Glacier National Park. Natl. Park Serv. 96 p. Neff, D. J. 1968. The pellet-group count technique for big game trend, census, and distribution: Thorpe, W. H. 1963. The ontogeny of behavior. a review. J. Wildl. Manage. 32(3):597-614. Pages 483-518 in John A. Moore, ed., Ideas in modern biology. Natural History Press, Garden Patton, D. R. 1974. Patch cutting increases deer City, N.Y. 563 p. and elk use of a pine forest in Arizona. J. Forestry 72(12):764-766. U.S. Department of the Interior. National Park Ser- vice. 1974. Environmental assessment: fire- Patton, D. R. and H. D. Avant. 1970. Fire stimulated vegetation management plan, Grand Teton National aspen sprouting in a spruce-fir forest in New Park. 47 p. (Processed) Mexico. U.S.D.A. Forest Service Res. Note RM- 159. 4 p. Villmo, L. 1975. The Scandanavian viewpoint. International Reindeer and Caribou Symp., PKOC. Pearson, H. A. 1968. Thinning, clearcutting, and 1:4-9. reseeding affect deer and elk use of ponderosa pine forests in Arizona. U.S.D.A. Forest Ser- Wallmo, 0. C. 1969. Response of deer to alternate- vice Res. Note RM-119. 4 p. strip clearcutting of lodgepole pine and spruce- fir timber in Colorado. U.S.D.A. Forest Service Pengelly, W. L. 1963. Timberlands and deer in the Res. Note RM-141. 4 p. northern Rockies. J. Forestry 61(10):734-740.

AZteration of Mule Deer Habitat Wallmo, 0. C. and R. B. Gill. 1971. Snow, winter distribution, and population dynamics of mule deer in the central Rockies. Snow and Ice in Relation to Wildlife and Recreation Symp. (ha, Iowa, Feb. 11-12, 1971) Proc.:l-15.

Wallmo, 0. C., W. L. Regelin, and D. W. Reichert. 1972. Forage use by mule deer relative to logging in Coloardo. J. Wildl. Manage. 36(4):1025- 1033.

Ward, A. L., J. J. Cupal, A. L. Lea, C. A. Oakley, and R. W. Weeks. 1973. Elk behavior in relation to cattle grazing, forest recreation, and traffic. Trans. N. Am. Wildl. Nat. Resour. Conf. 38: 327-337.

47 Alteration of Mule Deer Habitat INTERSPECIFIC COMPETITION BETWEEN MULE DEER, OTHER GAME ANIMALS AND LIVESTOCK

Richard J. Mackie

Department of Biology Montana State University Bozeman, Montana 59715

Abstract

Comparisons of available data on distributions, range use and food habits, and behavior indicate that mule deer may interact in a competitive relationship with each of the other species of wild and domestic ungulate with which they associate on western rangelands. Existing studies, however, have not produced substantive evidence for the existence of competition generally nor more than very general conclusions about its exact nature and importance; and most current thinking remains rooted in inference and speculation and is controversial at best. This essentially precludes any firm conclusions as to the possible significance of interspecies relations and competition in current trends of mule deer populations in western North America.

Mule deer (OdocoiZeus hemionus) rarely, if ever, ciation; (5) commensalism, in which one population exist in species populations completely isolated from is benefited but the other unaffected; (6) amen- contact with other wild and domestic ungulates. salism, in which one population is inhibited and the Throughout their distribution, they cohabit range- other unaffected; (7) parasitism and (8) predation, lands at least seasonally with one or more of the wherein one population is dependent upon and adverse- other wild ungulates native to western North America. ly affects the other by direct attack. Most of these rangelands are also grazed by domestic livestock, including cattle, sheep, horses, and, In the above context, competition is limited to occasionally, mules, burros, goats, and hogs. Local- those interactions which adversely affect growth ly, feral or "wild" populations of domestic animals and survival of both species populations involved as well as introduced wild ungulates also occur. and ultimately result in the elimination of one as Because of this, the possibility of competitive inter- defined by the competitive exclusion principle actions has occupied the minds of wildlife, range, (Hardin 1960). Others have defined it as active and livestock managers and scientists for many years; demand by two or more individuals of the same species and it is not surprising that interspecies relation- population (intraspecies competition) or members of ships of mule deer now loom as a possibly significant two or more species at the same trophic level factor contributing to recent declines in populations (interspecies competition) for a comon resource or of this species over much of the western United States requirement that is actually or potentially limiting and Canada. What is surprising, in view of the wide- (Miller 1967). In practical usage, "competition" spread attention given generally to interspecific usually has been applied rather loosely to include relationships of large herbivores and specifically almost any interaction with an assumed or real, to mule deer during the past half-century or more, negative outcome, including those in which the wel- is that remarkably few firm conclusions of general fare of only one species may be adversely affected application have emerged. Much of our current think- (amensalism of Odum 1959). ing remains rooted in inference and speculation and is controversial at best. This apparently applies Competition may involve elements of "interfer- also to almost all of our conclusions about the ence" as well as "exploitation" (Miller, 1967). importance of competition in natural ecosystems Interference refers to any activity which directly generally (Miller 1967). or indirectly limits a competitors access to a necessary resource, usually in a spatial context. Exploitation refers to utilization of a resource INTERSPECIES RELATIONS AND COMPETITION once access has been achieved, usually in the sense that two individuals or species with unlimited access Interspecific relationships of living organisms to a common source of food or nutrients will have have been viewed in many ways. Odum (1959) listed different abilities or opportunity to exploit the eight important interactions which may occur between available supply. two or more species populations: (1) neutralism, in which neither population is affected by association The role of interference in competition among with the other; (2) competition, in which each popu- large herbivores is largely unknown. Interspecies lation affects the other; (3) mutualism, in which aggression approaching territoriality, as required interaction is obligatory for the growth and survival by Miller's (1967) definition of interference, is of both populations; (4) protocooperation, in which not known among ungulates, at least in western North both populations benefit from a non-obligatory asso- America. However, an element of interference is implicit in Denniston's (1956) concept of "disturb- Kramer (1972) recently evaluated ecological ance" competition between moose (Alccs alces) and relationships of these two species in detail. Within cattle. Disturbance refers to the movement of one their zone of overlap, habitat preferences and some animal from, and/or avoidance of, areas used by aspects of behavior were distinctly different, while another, at least to the extent that alternate areas food habits were fairly similar. The latter, plus or habitats are available (Schladweiler 1974). Other some overlap in habitat usage where the two species wild ungulates, especially elk (Cervus canadensis), occupied the same area suggested the possibility of may react similarly to the presence of domestic live- competition in local areas; however, competition did stock (Jeffery 1963, Dzlke et al. 1965, Skovlin et al. not appear to be an important factor either generally 1968, Knowles 1975, Lonner 1975, Komberec 1976). or in recent extensions of the range of white-tailed Knowles (1975) indicated that radio-marked mule deer deer in northern areas where mule deer populations jn rest-rotationally grazed pastures either moved from were declining. the area or moved further and used all parts of their home range more frequently after cattle were turned EZk.--Elk occur generally across much of the range into the pastures in which they occurred. Between wild of mule deer. Wherever studies have been conducted, ungulates, bighorn sheep (Ovis canadensis) may avoid patterns of habitat usage of elk appear quite similar elk (Mair 1952) but dominate mule deer (Hunter and to those of mule deer; though elk appear to be less Kinghorn 1949), and mule deer may dominate over white- discriminating in their selection of habitat types tailed deer (Oducoileus virginianus) (Anthony 1972, and move more widely. Foods utilized by elk fre- Kramer 1973). Although the effect of disturbance on quently overlap preferences of mule deer; but both the biology of wild ungulates has received little vary considerably by season and location and food study to date, Geist (1970) indicated that repeated habits of elk generally appear to be broader and disturbance could result in voluntary withdrawal from more flexible than those of deer. On prairie- available habitat and confinement of the population montane forest mountain ranges, both animals consume to a smaller and less favorable area. similar grasses and forbs during spring and appear to prefer similar forbs during summer. Both may Evaluations of interspecies relations and compe- also browse on the same species during summer; tition among larger herbivores, including mule deer, though, if forbs are not available, elk often switch have largely involved the exploitational aspect. to grasses while mule deer browse more intensively. Thus, the extent to which two species graze the same In fall and winter, where available, elk trend to area and prefer the same forage is generally recog- grasses, but utilize some forbs and may browse nized as the main factor in interspecific competition intensively during periods of snow cover or when on western rangelands (Julander 1958). It might also crusting limits access to grass. Though mule deer be important that forage plants used in common be an tend to browse most extensively during winter in important source of food for either or both animals, most areas, they may depend heavily on forbs and/or in limited supply, and over-utilized or deteriorating grasses in some areas where available and shrubs as a result of the combined use (Cole 1958). are limited. On heavily forested ranges of western Montana and northern Idaho, both mule deer and elk Smith and Julander differentiated two kinds or may browse extensively throughout the year and levels of competition among large herbivores: prefer similar species. "forage" competition and "land use" competition. Though both involve the element of exploitation, the In general, available data suggest considerable former refers to common usage of preferred forage opportunity for interspecific competition between plants at levels above those considered proper for mule deer and elk where species populations occupy sustained productivity and yield, while the latter is the same range. Because elk appear to be more associated with comon use of a forage supply which adaptable and flexib1.e in their choice of habitats is adequate to meet requirements of both animals but and forage preferences, most authorities have con- where removal of one would permit increased numbers cluded that, in the event of interaction, elk would of the other. In either case, it is not necessary be the more efficient competitor and survive at the that competitors use the same area or forage plants expense of mule deer. However, there is as yet at the same time (Cole 1958). Use of a food by one little quantitative support of competition between animal during one season may preclude subsequent the two species being an important factor in the usage of that area or food by another. Also, inten- population ecology of either one. Among the few sive usage of an area or forage source by one animal accounts of elk-mule deer interactions in the liter- over a period of years may directly or indirectly ature, Cliff (1939) ascribed heavy deer mortality reduce forage yields or alter plant species composi- in Idaho during the severe winter of 1931 to heavy tion to the eventual detriment of another animal. utilization of important mule deer forage plants by elk.

INTERSPECIFIC RELATIONS OF MULE DEER AND OTHER Bighorn Sheep.--Although the distribution of mule UNGULATES deer almost completely overlaps that of bighorn sheep throughout the western United States and Mule Deer Interactions With Other Wild Ungulates Canada, bighorn ranges comprise only a very small proportion of the total distributional range of mule White-tailed Deer.--The range of white-tailed deer deer. Studies of local species populations indicate overlaps that of mule deer generally across the north- that in many areas at least they may utilize similar ern United States from the western Dakotas to eastern habitats and prefer much the same forage; while in Washington, from western Manitoba westward to Alberta others, habits diverged. In general bighorns appear and southeastern British Columbia in Canada, in north- to utilize grasses to a much greater extent and eastern Wyoming, the western portions of Nebraska, browse to a lesser extent than deer in most areas of Kansas, Oklahoma, and Texas, and parts of Colorado, comparative study, but sufficient overlap in plant New Mexico, and Arizona.

Interspecific Competition species utilized occurred to suggest competition at occur together. Most comparative studies have least locally. indicated broad differences in use of local habitat types and physiographic sites as well as in forage Moose.--Moose occur within the range of mule deer in preferences of mule deer as compared with cattle Canada from Saskatchewan west to British Columbia, such that competition is likely to be minimal in in Montana, Idaho, and Wyoming, northeastern Utah. most cases where ranges are properly stocked and and possibly very locally in a few other areas, in good to excellent condition. However, cattle Prescott (1974) recently reviewed interrelationships often make sufficient use of important deer forage with mule deer. Some similarities in habitat and plants and feeding areas to compete seriously where forage selection were evident in most areas. In stocking rates are high, when plant growth is Montana, as elsewhere, they may share both summer and reduced by drought or prior heavy usage, or when winter ranges and eat many of the same plants; and grazing begins too early, extends too long, or these overlaps probably result in competition in some occurs on critical winter or other seasonal range areas. Overall, competition probably would affect areas. Because of this, both the actual occurrence mule deer more drastically than moose (Schladweiler and the intensity of conflict probably vary widely 1974). in time and space.

Pronghorn Antelope.--Pronghorn antelope (AntiZocapra That cattle may "interfere" with deer usage of americanal occur in association with mule deer on all available habitats and exclude deer use in prairie and mountain valley or basin grass and shrub- some areas has been suggested by McMahan (1966), lands in many areas of western North America. Firebaugh (1969), Dusek (1971), and Knowles (1975). Although they may utilize much the same habitats and However, direct evidences of exclusion and quanti- prefer many of the same forage plants throughout the fication of the effects of competition by cattle on year comparative studies are lacking. Opportunities mule deer populations is generally lacking. McMahan for competition probably exist in many areas, espe- and Ramsey (1965) reported a low carrying capacity cially where higher mule deer densities occur on for white-tailed deer in all pastures continuously extremely open prairie lands. grazed by a mixture of livestock including cattle, as compared with deer-only managed areas. Repro- Mountain Goats.--Mountain goats (Orems americana) duction and survival of fawns in these pastures occur locally within the range of mule deer in many varied in relation to stocking rates with no fawns areas of the northern Rocky Mountains. Distributions ever surviving to yearling age on heavily stocked may overlap in these areas during summer and/or pastures. winter, with some similarities in habitat usage and forage selection. Although competition could occur, Sheep.--Range usage and food habits of domestic sheep few comparative studies have been conducted and may overlap those of mule deer even more closely interrelationships are generally obscure. than in the case of cattle. Cumulative data on interactions do little to alter the basic conclusion Other WiZd Ungu2ates.--Locally, Bison (Bison bison) of Smith and Julander (1953) that "the similarity may occur in association with mule deer as in the of sheep and mule deer diets is sure to cause con- case of the National Bison Range. In the southwest, flict wherever the supply of preferred (forage) collared peccary (Pecari tajacu), barbary sheep species is inadequate to satisfy the requirements (Ananotragus leruia), and locally perhaps some addi- of both animals...even though an adequate forage tional exotic ungulates may occur on mule deer supply obviates any actual conflict, there is com- ranges. Knipe (1957) suggested the possibility of petition in the sense that if part of the deer competition between pecarry and deer during some years population was removed, sheep numbers could be or in some areas where the availability of forage was increased and vice versa." Evidences of "interfer- low. Ogren (1962) indicated that barbary sheep eat ence" or local exclusion of mule deer from areas some of the same foods taken by deer, but that field grazed by sheep have not been recorded quantita- observations indicated that the apparent competition tively in the literature. may not be real because of differences in use of local habitats. Other Livestock and Feral Ungukxtes.--Both domestic and "wild" horses and burros may be associated with mule deer, grazing similar local areas and habitat Mule Deer Interactions With Domestic Ungulates types. While "wild" populations have increased due to protection in recent years, concern for possible Domestic livestock grazing has been a dominant competition has also increased; but as yet few use of western rangelands since the late 1800's; and quantitative data have appeared. Available informa- the vast majority of mule deer range has been or is tion suggests considerable differences in forage grazed at least seasonally. Viewed either on the preferences, but use of herbage as well as winter basis of its historical and long-term impacts on the browse species of mule deer may constitute serious kinds and amounts of vegetation on these ranges or competition affecting mule deer adversely. in terms of annual forage removal and associated short-term grazing affects, this usage has to rate as one of, if not the single most important land use or Multi-species Relationships environmental factor affecting mule deer habitat values. Frequently, mule deer occur in species populations associated with more than one other ungulate. Cattle.--Findings of intensive competition studies For example, both elk and cattle occur broadly as well as general comparisons of range use and food across the range of mule deer. Where they occur habits of mule deer and cattle have indicated that together, interactions may be intensified and/or some competition may occur wherever the two species vary from those of observed when only one is present.

Interspecific Competition Numerous studies have shown a high degree of similar- influence carrying capacities. Normal fluctuations ty in range usage and yearlong forage preferences of in weather and snow conditions, forage production, elk and cattle. In most respects the habits of elk predation, hunting, and other factors may elicit overlap those of deer on one hand and cattle on the changes in carrying capacities or certain species other. Further, elk clearly tend to avoid cattle responses and population consequences essentially whenever possible and seek those areas where no cattle indistinguishable from intra- or inter-specific occur (Skovlin et al. 1968, Lonner 1975, Komberec competition. 1976). Thus the presence of cattle tends to intensify opportunities for confljcc between elk and mule deer Similarities and/or differences in distribution, and, perhaps between mule deer and cattle as well. range use, and food habits are not evidence a priori Elk withdraw into areas least grazed by cattle and/or for or against a competitive relationship. There concentrate in areas where no cattle occur, possibly may be several reasons for this. causing or increasing the intensity of interaction where none or less occurred without cattle. Also, Only rarely, if ever, have we had opportunity reductions in cattle numbers on many ranges, removal to record these kinds of data for mule deer (or any from others inclucling many winter deer and elk ranges, other species) in a situation where no other species and more restrictive+anagement of elk on mutually occurred. Thus, most existing information has been used areas have all served to favor elk and intensify collected in places or under conditions when inter- potential conflict with mule deer. action was a matter of fact. Because of this, we usually find ourselves using data, which in themselves reflect effects of interaction, to determine PROBLEMS IN ASSESSING INTERSPECIFIC COMPETITION whether interaction and competition are occurring.

As the preceding discussions indicate, it is not Secondly, not all interactions need to be com- especially difficult to obtain data indicating the petitive. There are numerous reports in range and possible occurrence of some interaction andfor exploi- wildlife literature suggesting increased avail- tation-type competition among various species or ability, palatability, or production of forage plants species populations of larger herbivores. Clearly, for one animal as a result of grazing or browsing mule deer may interact in competitive relationships activities of another. Bell (1971) described situa- with each of the other ungulates with which they tions in the Serengetti Plains of Africa in which associate. Opportunity, however, need not prescribe several species of herbivores grazed the same area the fact; and, by itself, has little predictive value. and, to a certain extent, the same plants in a Yet, existing studies, even with careful design, con- mutualistic or commensalistic relationship. On some tinued measurement and observation over several years, western rangelands at least, the conversion of and exhaustive analysis, have not produced substantive perennial grasslands to shrub and/or annual grass- evidence for the existence of competition nor more forb types as a result of heavy early livestock than very general conclusions about its exact nature grazing is believed to have improved forage condi- and importance. The lack of adequate means of tions for mule deer. Reductions in densities of measuring the biological and ecological effects of native perennial grasses paved the way for the sub- competition or other interactions and distinguishing sequent abundance of palatable shrubs and/or intro- these effects from those of other population regula-- duced grasses and forbs which are more digestible ting mechanisms and factors which express themselves than native perennials (Longhurst et al. 1968, in the same way may be a major reason for the fact 1976). A similar relationship is implicit in the that few firm conclusions have emerged. In addition, concept that "sound grazing practices play an we may lack either adequate means or sufficient important role in maintaining adequate browse stands perspective to interpret existing data on habitat essential for a healthy population of big and upland requirements and relationships. Because of this, game (Clawson and Lesperance 1973). " both the kinds of data and the criteria which we commonly employ in assessing interactions probably Furthermore, our preoccupation with more have some important limitations. preferred and important forage plants in assessing competition may have ignored vital roles of lesser The expected effects of interspecific competition species in the diets of grazing animals and perhaps among ungulates are those which directly or indirectly more subtle competitive relationships with respect depress carrying capacity, create or intensify intra- to their use and availability. Biologists have specific competition, and ultimately result in changes lung recognized an apparent requirement for a variety in numbers or distribution, or both. Most wild of forage items in the diet of large herbivores; ungulates, including mule deer, appear to be fairly and both Smith (1959) and Longhurst et al. (1968) adaptable in their choice of Food and habitat require- have indicated that there may be physiological limits ments. Thus, under natural conditions they occupy a as to the amount of certain species, e.g. big sage- rather wide range of habitats wherein carrying brush, that deer can consume. Longhurst et al. capacities and species density vary naturally in (1968) related this to inhibitory effects of essen- relation to the kinds, quality, and amounts of food tial oils on rumen function. Similarly, Freeland and cover available in localareas. In typical range- and Janzen (1974) point out that many plants normally land situations, in which population densities of fed upon by herbivores contain toxic materials which either or both competitors are at or close to their can have detrimental effects unless consumed with carrying capacities, it is difficult to distinguish other kinds of plants which either offset or neutral- the additional effects, if any, of interspecific ize their toxicity. competition from those of intraspecific competition. It is also diffirult to distinguish effects of inter- Finally, competition for forage may begin long species interactions and competition from those of before preferred forage plants used in common are various other environmental factors which similarly "overused". Livestock grazing trials have shown

Interspecific Competition repeatedly that rates of weight gain in heavily stock- Dusek, G. L. 1971. Range relationships of mule deer ed pastures deviate from those under lighter stocking in the prairie habitat, northcentral Montana. almost from the time cattle are placed in the pastures M.S. Thesis, Mont. State Univ., Bozeman. 63p. (cf. Woolfolk and Knapp 1949, Kipple and Costello 1960, Reed and Peterson 1961). The rate at which an animal Firebaugh, J. E. 1969. Relationships of mule deer can find food depends upon the density of food in its to livestock on summer range in the Pryor Moun- environment, the amount of time and effort spent in tains, Montana. M.S. Thesis. Mont. State Univ. looking for food, and its efficiency in feeding all Bozeman. 55p. may be influenced by preemption or common usage well before total utilization reaches a "proper" level. Freeland, W. J. and D. H. Janzen. 1974. Strategies in herbivory by mammals: The role of plant secondary compounds. Am. Nat. 108(961):269-289. CONCLUSIONS Geist, V. 1970. A behavioral approach to the The fact that we must admit to knowing little management of wild ungulates. pp413-424. In about the exact nature and importance of competition E. Duffey and A. S. Watt (ed). The scientific essentially precludes any firm conclusions as to its management of animal and plant communities for possible significance in the current trends and conservation. The 11th Symposium of the British status of mule deer populations in Western North Ecological Society. Blackwell Scientific Publ., America. This does not mean that competition is not Oxford. or has not been of some or even considerableinfluence. Rather, it serves to point out that much remains to Hardin, G. 1960. The competitive exclusion princi- be accomplished in the way of finding ways and means ple. Science 131:1292-1297. of more effectively assessing interspecies relationships and applying our current knowledge to situations Hunter, G. N. and R. G. Kinghorn. 1950. Mountain of potential competition on rangelands. Since exiat- sheep drive mule deer from food. J. Mammal. ing data do not or cannot satisfy the demands of 31(2) :193. multiple use land managers attempting to accommodate all uses, it seems imperative that we redirect our Jeffery, D. E. 1963. Factors influencing elk thinking and efforts to establish valid data and distribution on Willow Creek summer range, conclusions as rapidly as possible. Until we can Utah. M.S. Thesis, Utah State Univ., Logan. fully document the biological and ecological significance of interspecies competition we can only con- Julander, 0. 1958. Techniques in studying competi- tinue to say maybe to the questions of whether tion between big game and livestock. J. Range competition is occurring or important. Manage. 11(1):18-21.

Kipple, G. E. and D. F. Costello. 1960. Vegetation LITERATURE CITED and cattle responses to different intensities of grazing on short-grass ranges on the central Anthony, R. G. 1972. Ecological relationships Great Plains. U.S.D.A.Tech. Bull. No. 1216. 82p between mule deer and white-tailed deer in southeastern Arizona. Ph.D. Thesis. Univ. of Knipe, T. 1957. The javelina in Arizona. Ariz. Arizona (Lib. Congr. Card No. Mic. 72;31,840). Game & Fish Dept., Wildl. Bull. 2. 96p. 123 p. University Microfilms. Ann Arbor, Mich. Knowles, C. J. 1975. Range relationships of mule Bell, R. H. V. 1971. A grazing ecosystem in the deer, elk and cattle in a rest-rotation grazing Serengeti. Sci. Am. 225(1):86-93. system during summer and fall. M.S. Thesis, Mont. State Univ., Bozeman. lllp. Clawson, W. J. and A. L. Lesperance. 1973. The en- b vironmental role of range livestock. Proc. Komberec, T. J. 1976, Range relationships of mule Western Section, Amer. Soc. of An. Sci. deer, elk and cattle in a rest-rotation grazing 24:38-41. systan during winter and spring. M.S. Thesis. Mont. State Univ., Bozeman. 79p. Cliff, E. P. 1939. Relationship between elk and mule deer in the Blue Mountains of Oregon. Trans. Kramer, A. 1972. A review of the ecological rela- N. her. Wildl. Conf. 4:560-569. tionships between mule and white-tailed deer. Alberta Fish and Wildl. Div, Occ. Paper No. 3. Cole, G. 1958. Big game-livestock competition on 54 p. Montana's mountain rangelands. Montana Wildl,, April 1958:24-30. -, 1973. Interspecific behavior and dispersion of two sympatric deer species. J. Wildl. Dalke, P. D., R. D. Beeman, F. J. Kindel, R, S. Robel, Manage. 37(3):288-300. and T. R. Williams. 1965. Use of salt by elk in Idaho. J. Wildl. Manage. 29(2):319-332. Longhurst, W. H., H. K. Oh, M. B. Jones, and R. E. Kepner. 1968. A basis for the palatability Denniston, R. H. 11. 1956. Ecology, behavior and of deer forage plants. Trans. N. Am. Wildl. population dynamics of the Wyoming or Rocky Nat. Resour. Conf. 33:181-192. Mountain Moose. AZces aZces shirasi. Zoologica 41(14) :105-118.

53 Interspecific Competition Longhurst, W. H., E. 0. Garton, H. '3. Heady, and G. E. Connolly. 1976. The California deer decline and possibilities for restoration. Paper presented at Annual Meeting of the Western Section of the Wildlife Society, Fresno, California. Jan. 30-31, 1976. 37 pp. a Lonner, T. N. 1975. Montana Cooperative Elk-logging study. Job 11-B, Long Tom Creek Study. pp. 60- 72. Prog. Rept. January 1-December 31, 1974. 146 p.

Lovaas, A. L. 1970. People and the Gallatin Elk herd Montana Dept. of Fish and Game, Helena. 44p.

Mair, W. W. 1952. The impact of an introduced population of elk upon the biota of Banff National Park. Unpub. M.S. Thesis. University of Alberta. 98pp.

McMahan, C. A. and C. M. Ramsey. 1965. Response of deer and livestock to controlled grazing in Central Texas. J. Range Manage. 18(1):1-6.

McMahan, C. A. 1966. Suitability of grazing enclosures for deer and livestock research on the Kerr Wildlife Management Area, Texas. J. Wildl. Manage. 30(1) :151-162.

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Interspecific Competition DEER RANGE IMPROVEMENT AND MULE DEER MANAGEMENT -'1

Paul T. Tueller Professor

Renewable Natural Resources Division Max C. Fleischmann College of Agriculture University of Nevada Reno Reno, Nevada 89507

Abstract

Range improvements for mule deer in the western United States consist of (1) range seedings, (2) grazing management systems including fencing, (3) tree and brush removal, (4) water development, and (5) miscellaneous land treatments. The benefits, while intuitively positive, have rarely been successfully measured by documenting either changes in mule deer population size or behavior modifications. Collectively, deer range improvement practices provide a combination of factors that are beneficial to mule deer. Monotypic seedings and most intensive grazing management systems developed within the range of the mule deer are apparently of little benefit. Tree and brush control projects are of greater benefit and water developments are beneficial primarily in the more zeric portions of the mule deer range. Prescribed burning is generally beneficial but only in certain habitats. Large variations in range forage productivity based on seasonal rainfall, "natural" population fluctuations, and intensive interspecific competition may mask the positive benefits of range improvements for mule deer. It is recommended that the best possible techniques be used to evaluate benefits in terms of populations and behavioral changes that result from the effort to improve ranges.

INTRODUCTION In this paper I have attempted to review the . literature concerned with mule deer range improvement practices. I have, in my search, sought those An estimate of the expenditures for range improve- studies that have shown either an increase in herd ment for mule deer would be revealing. Revealing in number actually attributed to an improvement or, the sense that considerable tax dollars have been secondly, studies showing how the deer range improve- spent to improve the general quality of the mule deer ment practice has caused a significant change in range while the benefits have rarely been success- deer behavior resulting in management alterations. fully measured. The benefits have been intuitively Negative effects were also sought. Population changes positive. Ranges with low amounts of "desirable" or fluctuations reported here are assumed to be deer forage are improved by either reseeding important valid. Others in this symposium will tell us how species, reducing undesirable species, or both. Water good the estimates are. developments are sometimes beneficial and fences either help or hinder. DEER RANGE IMPROVEMENTS FOR MULE DEER

Expected benefits, though seldom measured, have It appears to be well established that over- been assumed to be such things as improvement of populations of deer lead to overuse of the habitat, herd health, increased vigor of individual animals, followed by deer mortality (Severinghaus 1951; i.e., healthier does and stronger bucks. This, then, Russo 1964). Cheatam and Severinghaus (1950) found in at least the hypothetical sense, is followed by an variations in fertility related to range conditions. increase in fawnldoe ratios and herd numbers increase - Likewise, deer productivity has been shown to vary to the improved carrying capacity level? from habitat to habitat (Taber 1953), depending upon the availability and nutritive quality of the ~~~~~ '/ Paper presented at the Symposium entitled forage (Julander et al. 1961). The latter study - showed that two mule deer ranges in Utah and Idaho "Mule Deer Decline in the West," April 29-30, 1976. Fall Logan, Utah. had striking differences in deer productivity.

55 Deer ,:ange Improvement and Mule Deer Management weights of the Utah fawn bucks and does were 72 and Several researchers have found a close relation- 65%, respectively, of weights of the Idaho fawns. ship between the percentage utilization of bitter- Forage production, ovulation rates and fetal weights brush by deer and fawn survival. For example, Dasmann were all higher on the Idaho range. The authors and Blaisdell (1954) showed a relationship between the concluded: "A good summer range, capable of carry- intensity of bitterbrush cropping and the success of ing deer in good condition through the breeding the succeeding season's fawn~ngas reflected by fall season is necessary for maximum herd productivity." does/fawn ratios. They concluded that bitterbrush can serve as an indicator species in the management Swank (1958) found that summer forage nutrition of the deer herd. Under conditions of their study, strongly controlled ovulation rates and the number of when the cropping of bitterbrush leader growth fawns developed per doe. A dry summer coupled with exceeds 25 percent, a moderate decline in fawn sur- excess deer numbers resulted in poor bucks and an vival can be expected the following year. When extremely low fawn crops (28 fawns per 100 does). utilization exceeds 34 percent, a steep population decline can be expected. Can tag sales and control Robinette et al. (1952) studied deer mor- of hunter success be used to remove animals from tality in relation to range condition after the these heavily utilized ranges? severe 1948-49 winter in Utah and found the follow ing : It has been known for many years that good deer forage is characteristic of "sub-climax ecological Herd Mortality Lbs. green forageldeer-day use conditions" (Leopold 1950). Lyon (1966) described the benefits to deer and elk populations provided 9% 57 by wildfire in the northern Rocky Mountains in the 26% 13 early part of the century. This post-fire disclimax 42% 9 vegetation proved to be very favorable for wildlife. Shrub dominance favorable to deer and elk may con- Deer winter losses varied inversely with the tinue for another 50 to 80 years but will eventually amount of available forage on the winter range. be displaced by trees. Future managers will be required to make decisions relative to trees versus Taber (1953) found that black-tailed deer shrub habitat and the desirable proportions of each. showed differing reproductive rates, depending upon cover type. Open brush types were consid- Over much of the range of mule deer heavy Iive- erably more productive (147 fawns1100 does) stock grazing has been instrumental in providing a than either burned sites (115.6 fawns /does) desirable sub-climax vegetation with grasses reduc- or stands of mature brush (84.3 fawnsllOO does) ed and browse and forbs increased. Longhurst et al. at the beginning of the winter. (1976) believe that the general shift from sheep to cattle is strongly related to the mule deer decline. Another good example of the strong relation- Their hypothesis is that cattle tend to overgraze ship between deer population changes and habitat ranges to the detriment of deer forage or that sheep differences brought about by management is the do a better job than cattle in maintaining the suc- study by Biswell et al. (1952) with black-tailed cessional forbs and grasses which are necessary for deer in the North Coast Range of California. deer. Three areas were compared: (1) heavy brush cover, (2) wildfire burn, and (3) open brush consisting Deer range is enhanced when certain species are of an interspersion of grass with patches of dense prevalent. Numerous studies have described deer food brush. habits (Dasmann and Blaisdell 1954; Anderson et al. 1965; Wood et al. 1970; Tueller and Lesperance 1970; Deer/sq. mi. Ovulation Rates (%) McCulloch 1973; Goodwin 1975; and Tueller 1976) Heavy brush 10-30 84 showing the high preference and apparent palatability Wildfire burn 5-160 116 of a relatively few species. Overbrowsing by deer Opened brush 40-110 14 7 gives less desirable plants a competitive advantage and the entire flora tends to shift to composition Populations in the heavy brush and opened brush were less desirable for mule deer (Leopold et al. 1947). rather stable; but in the wildfire burn, large num- Management programs designed to increase important bers of deer moved in when the sprouts were young species are clearly needed. In addition, managers and tender and moved out during cold winter. These should not lose sight of the fact that certain data show how deer vary in their ability to repro- naturally occurring plant communities are much more duce and grow in different kinds of habitats. desirable than others with respect to deer use. Several authors have shown significant differences Segelquist (1974) attempted to study the effects among plant communities relative to deer use (Darling of forage clearings on the health and population 1937; Rasmussen 1941; Biswell et al. 1952; Depaoli characteristics of a herd of 23 white-tailed deer and Tueller 1970; Mackie 1970; Tausch 1973; Tueller from 1968-72 in a 600-acre fenced enclosure in Arkan- and Monroe 1975). Plant communities shown to be of sas. Loss of nearly half the animals as a result of special significance should receive the highest pri- predation, the collecting of animals for necrosy, ority for improvement and maintenance funding. For death from unknown causes, and animals escaping from example, in Montana, Mackie (1970) found the Pinus- the enclosure precluded the making of valid conclu- Juniperus habitat type to be of greatest importance sions concerning the influence of management changes during summer, Artemisia-Agropyron in fall and winter, on population characteristics of deer. This study and the Artemisia-Agropyron and Pinus-Agropyron types seems to exemplify the problems that are often en- received the greatest use in the spring. Tueller and countered. Monroe (1975) reported from Nevada that the Artemisia

Deer Range Improvement mzd Mule Deer Mcmagement 56 tridentata/Purshia tridentata/Poa secunda, Cercocar- and likewise by the provision of new water pus ledifoZius/Symphoricarpos longif Zorus/f orb and sources. Artemisia tridentata or nova/Purshia tridentata/ Festuca idahoensis or Agropyron spicatwn plant com- (5) Miscellaneous treatments - fertilization, chemi- munities are of considerable importance for mule cal treatments to remove competing vegetation, deer Statewide and therefore should receive the and other techniques have been used to improve greatest management input. deer ranges.

Other generally uncontrollable factors are known Range Seedings to have strong definite influences on deer range vegetation and subsequently on deer population size. The techniques for seeding to restore mule deer These include, but are not necessarily restricted to, ranges have been carefully described by Plumer et al. the following: drought, climatic anomalies, flooding 1968. Successful seeding requires a consideration of with intense erosion, and fire. Wallmo (1959 & 1962) various techniques, e.g., burning, chemical treatments, described the influence of drought on mule deer in interseeding, and other planting procedures. The the Chihuahuan desert of Trans-Pecos. Texas. A severe need is to select species with the following charac- 6-year drought in the mid-1950's reduced deer density teristics : from 4.5 to 6.5 deer per 100.ha. during the drought. Within three years after the drought, the deer popula- High in nutrients for deer. tions rose to over 11 deer per 100 ha. Forage, par- Cured or mature with a high supply of ticularly shrubs, significantly increased at the same nutrients desirable for mule deer health. time. White-tailed deer populations in Texas, Arizona, Readily available seed source at a reason- and throughout the Southwest are regulated to a able cost. large degree by precipitation during the preceding Strong emergence (possible need to protect year or 18 months (Shaw 1965; Teer et al. 1965). seed and seedlings from rodents). McColm (1976) reported that a Nevada drought between High establishment percentages (growth 1959 and 1961 triggered a Statewide deer population through the first field season). decline that did not bottom out until 1966. High survival percentages (regrowth follow- the first and second winters). Many years ago, Darling (1937) described signi- Drought and frost hardiness. ficant interactions between climate and vegetation Rapid growth rates. as it related to deer movement. Mackie (1970) des- High productivity of usable deer forage. scribed deer movement or land use in relation to Self-renewing (good seed production fol- steepness of slope and aspect or exposure, as well lowed by volunteer establishment). as climate. Mule deer distribution and migration patterns are strongly influenced by climate in the After seed selection, recommended seeding and Great Basin and Intermountain Region and tend to vary management techniques can then be followed to prod- considerably from year to year. uce a desirable stand of vegetation with the important required characteristic of species diversity These data support the intuitive feeling that (Plummer et a1 1968; Tueller and Monroe 1975). the welfare of deer is generally enhanced under good range conditions and that the converse is true, Plummer's work with actual seedings, along with namely that poor range conditions diminish the vigor, the observations of Tueller and Monroe (1975). Mackie reproductivity, and general welfare of our deer herds. (19701, and many others, clearly show the importance The logical result of this thinking has been programs of providing a mixture of forbs, grasses, and browse to improve range conditions. These programs gener- for optimum deer use. Plumer et al. (1966) also ally have consisted of the following: list the important species that should be considered for use on mule deer ranges and they and others are (1) Range seedine - most have been done primarily continuing to screen species for good adaptability. for livestock, although mule deer may have received some side benefits. Some have been There is some concern that it is often difficult accomplished primarily for mule deer and, in to objectively evaluate vegetation trends for mule some cases, livestock, as well have benefited. deer. The reason is that animal numbers often are such that the new vegetation is quickly overbrowsed (2) Grazing management - an obvious example would or overgrazed and cannot survive after establish- be fencing to exclude cattle during the summer ment. This, of course, suggests the need for deer from important winter deer ranges. number management, including better distribution.

(3) Tree and brush control - removal of mature, over- Revegetation should be accomplished first, where mature, and decadent pinyon-juniper trees, by needed, for critical deer ranges. Often, these criti- either cabling or chaining, has been an exten- cal deer ranges are winter ranges and may be critical sively used technique for improving deer ranges. only one out of 10 years. They are an absolute Also, stands of heavy brush have been opened necessity during that tenth year and may help pro- to increase the relative composition of browse, vide proper use of all adjacent deer ranges during forbs, and grasses for mule deer use. Prescribed the non-critical years. burning has sometimes been used as a technique to accomplish the same results. Over one million acres in Nevada have been seeded to adapted exotic perennial grasses. Simi- (4) Water developments - deer are influenced in lar acreages have been seeded in adjoining states their pattern of land use by the lack of water

57 Deer Range Improvement and MuZe Deer Management within the range of mule deer. Do mule deer use Rest-rotation grazing systems or other systems perennial grass seedings in the Great Basin and designed to enhance the vigor, reproduction, and Intermountain Region? If so, when and how are they growth of a variety of range plants must also have important? Actual studies are limited. Plummer an influence on populations of wildlife. Grazing and Stopely (1959) found Agropyron cristatwn management systems designed to enhance monotypic (crested wheatgrass) to be one of the grasses stands may cause a reduction in good mule deer grazed by mule deer in the early spring or ranges habitat (Cole 1968). Other systems may, because treated for pinyon-juniper control. Investiga- of their design, enhance the accumulation and main- tions in south-central Nevada revealed 90% utili- tenance of a diversity of species. A diversity of zation of A. cristatuni by "deer and rabbits"; species will then serve to attract deer use (Tueller however, no apparent effort was made to differ- and Monroe 1975) . entiate the relative degree of utilization by the two species (Stinson 1964). Rumen analysis of No studies of grazing management systems have two wintering mule deer on rehabilitated pinyon- included definitive analysis of resident deer herd juniper range in Utah shaved the occurrence of changes. For example, a Wyoming study (Gibbens and mature seedheads of A. cristatum in the sample Fisser 1970) concluded after a 4-year study of a (Plummer et al. 1966). Urness (1966) concluded 68,000 acre rest-rotation grazing system, that, al- that crested wheatgrass "is actively sought by though resident deer were seen in all pastures, deer on winter range and is, when available, "there are no indications of an increase in the Important in fall, spring, and snow-free periods resident population." in winter." Fences designed to remove livestock from key Cole (1968), in Nevada, studied crested wheat- deer ranges where competition is known to occur grass seedings in areas adjacent to known mule constitutes a positive treatment to improve deer deer ranges. Of 25 seedings studied, only three range. I found no published studies reporting showed a measurable use by mule deer. Those such benefits but such fences in Nevada have been sites found to be used by deer contained resi- instrumental in improving heavily used winter dual browse that was thought to account for the ranges that cattle have grazed for browse in late measurable deer use based on pellet group counts summer and fall. and browse use. Cole concluded that mule deer range was not extended by crested wheatgrass Tree and Brush Control seedings in Nevada on ranges not previously used as winter ranges. The monotypic nature of crested Tree and brush control for improvement of mule wheatgrass seeded range apparently inhibits utili- deer habitat has been practiced rather extensively zation of all but peripheral areas of such range. for the past 25 years. Terrel and Spillet (1975) If large enough, this monotype may restrict or alter quote Box et al. (1966) indicating that between 1950 mule deer movements from summer to winter ranges. and 1964, 3 million acres of pinyon-juniper woodland in 1200 projects have been converted in the U.S. Grazing Management Systems This, along with the over three million acres of sagebrush control in the West and control of other brush Is it possible to include deer in a grazing types not so well documented, constitutes a consid- system including livestock? There is no reason why erable land treatment for the benefit of mule deer. not, although it seems that such has been rarely accomplished. The important consideration here The basic question that keeps rising is.this: would be to assure that deer and livestock are not Do these treatments actually increase deer numbers competing for the same forage. In the Great Basin via the generalized mechanism discussed in the intro- it has been shown that there is a mule deer-livestock duction? First of all, it seems very clear that deer competition period that occurs in late summer and are attracted to the improved areas. Tausch (1973) early fall when livestock feed heavily on bitterbrush showed in Nevada that deer use increased on the pin- (Tueller and Monroe 1975). At this time the bitter- yon-juniper control areas. However, deer use was brush is still carrying on photosynthesis and restor- found to be highest on those areas originally containing carbohydrates to depleted roots and is, therefore, ing the greatest diversity. The level of use was also susceptible to browsing damage. Winter deer brows- dependent upon the nearness of untreated escape cover ing of the dormant bitterbrush is less damaging if and on the close proximity of the treated area to at all. existing deer use areas.

In Nevada, key winter deer ranges should Cole (1968), also working in Nevada, found probably have livestock use removed by fencing. The increased deer use inside pinyon-juniper control fences themselves nay constitute a hazard, but depend- projects. At one site peripheral paired plots ing on the terrain, may be placed in places that would showed an 87.5% increased utilization in the treated not directly interfere with known spring-fall migra- range. However, analysis over the entire area, i.e., tory routes. Longhurst et al. (1976) re~ortedblack- within the chaining, showed only a 15% increase, tailed deer mortality as one deer lost annually for suggesting the strength of the edge effect. each 8 miles of fence. This was an area with high deer density (100/square mile). They concluded that Terrel (1973) found increasing deer use in fences account for the loss of several thousand deer the vicinity of pinyon-juniper chainings but in each year in California. the natural undisturbed pinyon-juniper. In the initial 12 years post-treatment in Terrel's Utah study, no increase in deer numbers was correlated with pinyon-juniper conversion.

Deer Range Improvement and Mute Deer Management 5 8 In an Arizona study (Urness 1974) deer use An area of lodgepole pine and spruce-fir forest was found to be lower by 114 to 112 on root-plowed in Colorado was clearcut in narrow strips alternating areas when compared to adjacent brush fields even with uncut strips (Wallmo et al. 1972). Production though production of high-quality forbs was much of deer forage 15 years after logging was 47% greater greater on the root-plowed area. The author pointed on cut strips. Tame mule deer used in grazing studies out that the lower deer use figures for the 80-acre obtained 63.3% of their forage from cut strips, root-plowed sites does not necessarily reflect low 27.4% from uncut strips and 9.3% from logging roads. relative use. Only feeding was taking place on the These sites composed 44.2, 49.4, and 6.4 percent, root-plowed acres, while feeding, resting, ruminat- respectively, of the study area. Mule deer density ing, etc., are taking place on the undisturbed areas. figures derived from carrying capacity determina- Even though deer spend less time on the brush- tions on these sites resulted in numbers far in controlled areas, the increased feed may compen- excess of deer numbers estimated for the area. This sate for the lack of use, providing treatment size is another good example of deer congregating on an is moderate. This study indicated that brush control area as a result of habitat improvement but without areas should not exceed 300-400 yards in width and data on benefits to herd size or structure. no more than 50 percent of an area should be treated. Also, some intact brush should be left on all Also, a subsequent study (Regelin et al. 1974) exposures since mule deer in the area of the study showed that the unlogged forest produced enough deer change exposure preference, seasonally. Herd popula- forage, adequate in the nutritional parameters tion changes were not reported, although management measured, to carry more deer than are presently preferences seemed apparent. estimated to occupy the summer range. Deer populations in the study area are apparently limited An elongated burn area in an "unthinned" treat- by the amount of available winter range. In this ment on the Wild Bill study site in Arizona was case further range improvement and revegetation may considered to be a "forest opening" known to be pre- be futile since the limiting factor is associated ferred by deer (Kruse 1972). Deer use on the burned with sites removed from those being studied, namely, area showed a consistent yearly rise from 1968-70. the winter range. Deer use on the clearcut and thinned ponderosa pine areas had been steadily decreasing (after an initial It seems apparent that new brush or tree con- high use value immediately after the treatment) from trol treatments have benefits due to increased use 1964-67. These data (Table 1) show that the deer in the years immediately post-dating the treatment. moved from the clearcut and thinned area to the fresh Question! How often and how many treatments of what burn in the unthinned area, thus concentrating their size in a given habitat are required to provide use on the most favorable sites. The deer readily optimum benefit to mule deer populations? moved their use to a newly created site, in this case, a wildfire occurring in the control or unthinned site. Water Developments

Longhurst et al. (1976) have reported data in Water developments have the potential to accom- California to show that a decrease in wildfires due plish at least two things in a deer range improvement to better fire control, in spite of a trend toward project. First of all, increased distribution of more fire starts, has reduced deer habitat. In some water will allow deer to move onto and use ranges not locations they found high correlations between buck normally used and second, the provision of water in kill and acres burned. They suggested the possibil- droughty areas can provide a nutritional factor that ity that fires at higher elevations may improve the can be very influential in animal vigor and herd supply of forbs. However, in much of the Great Basin, health and subsequent population increases. A nega- most fires occur at lower elevations, thus tending to tive effect may be the fact that livestock also reduce this benefit over much of the mule deer range move in. although some use may be made of cheatgrass (Bromus tectorwn) in winter and early spring. Prescribed In New Mexico (Wood et al. 1970) mule deer burning certainly must be fully developed in future densities increased when permanent water sources management programs. were developed in areas which had little or no free water. Under conditions of this New Mexico study it was found that the desirable distance between water sources was 2-1/2 to 3 miles. On one poorly watered TABLE 1. Deer pellet groupslacre on a ponderosa pine site in northern Arizona (from Kruse 1972). range, deer densities increased from 1.6 deer per section in the first year to 13.0 the fifth year. 1964:1965:1966:1967*:1968:1969:1970: Substantial increase in deer densities on some areas within a few months led the authors to conclude that Clearcut "deer can be attracted into a newly watered area Seeded 16: 7: 7: 2 : 0: very well and that when the water sources were 2: 4: allowed to deteriorate, it was demonstrated, equally Native 42:ll:ll: 0 : 7: 0: -: as well, that deer can be forced to leave an area." Thinned They also concluded that these benefits can be 20lsq.ft.l 4:13: 2: 9 : -: 0: -: maintained and deer held on the areas permanently. 401 acre of 124 : 31 : 2 : 2 : 0 : 0 : - : 601 basal 36 : 33 : 2 : 0 : 2 : 0 : - : Mackie (1970) in Montana found "that the use 801area 36: 0: 0: 2 : 4: 0: -: of range by mule deer decreased sharply at distan- Unthinned 18: 4: 0: 0 :11:26:67: ces of a mile or more" from water. Observation "during summer and fall when 'permanent' water Burned sources would be most important, were within 0.75

Deer ,Tange Improvement and Mute Deer Management miles of a water source. The number of observa- A separate example of a miscellaneous or inno- tions at greater distances decreased as distance vative treatment is found in carbon black treatments increased, with negligible use at 2 miles or more." in Colorado (Regelin and Wallmo 1975). High eleva- However, the author concluded "that the distribution tion (2310-2350 m.) deer ranges in Grand County, of water on the study area even during the most arid Colorado are often limited due to deep snow. Carbon years was not a significant factor in determining black was broadcast on plots at a rate of 336 kglha mule deer distribution." (34.4 f/m2). Melting of snow was accelerated on all treatment plots, but particularly on south aspects. Apparently on the more xeric New Mexico site On these slopes average snow depth was reduced by the influence of distribution and density was signi- 91.8 percent when compared with control plots (7.4 ficant while on the more mesic Montana site the percent). The reduction was 50.5 percent on east relatively greater availability of water obviated slopes. The influence on the vegetation was not the influence of water distribution on mule deer investigated but additional forage could be made movements and densities although, in the latter available at difficult time. study, density differences were not recorded. Winter feeding of deer may possibly be consid- Observations by this author in Nevada indicate ered as an indirect method of range improvement. that there are several potential summer deer ranges How? By "releasing" pressure on heavily grazed win- in Nevada that are not used due to a lack of water. ter range. However, this technique is of question- One then wonders if, because of their strong habitual able benefit and desirability. In a 1944 study in nature (Gruel1 and Papez 1965), deer can be "inter- Utah, Doman and Rasmussen concluded "winter feeding ested" in these good ranges even if water is provided. of mule deer . . . is, at best, only partly success- Apparently this happened in New Mexico. I am not ful, and expansion of such a program is of doubtful certain it would be successful in Nevada, but a value. It appears desirable to regulate the deer study has not been conducted. population so that supplemental winter feeding as a regular program can be discontinued." Miscellaneous Improvement Techniques INTERPRETATION AND CONCLUSIONS It is important that new and innovative deer range improvement practices be developed. The litera- Deer range improvement practices consist of (1) ture reveals few good examples. Perhaps increased range seedings, (2) grazing management systems, includ- and wiser use of the time-honored techniques will, ing fencing to enhance certain native and introduced in the long run, provide the best means of produc- species, and natural plant communities, (3) tree and ing deer forage and increased deer populations up brush removal with and without artificial revegetation, to optimum carrying capacity. (4) water developments, and (5) miscellaneous treatments. The relative amounts of these various prac- Fertilization constitutes one miscellaneous tices throughout the range of mule deer is not well deer range improvement technique, although it is known. most often used along with revegetation and other procedures. For example, Anderson et al. (1974) Some general observations can be made. Approxi- studied the influence of fertilizating wavy leaf oak mately 1,000,000 acres of perennial grasses have been brush ii~New Mexico for mule deer. Urea or ammon- seeded in Nevada. Only a fraction of this, probably ium sulfate was applied to this range and the less than 2 to 3 percent, has been of positive bene- result was a significant increase in leader growth fit to mule deer. The negative effects have not been by mountain mahogany (Cercocurpus Zedifolius). studied extensively, only implied, but they might be No increase in leader growth was found for either sizable. Of course, these revegetation projects were fourwing saltbrush or wavy leaf oak. Crude protein accomplished for livestock only. Probably a similar increased significantly in the oak leaves after amount of seeding has been accomplished in other urea fertilization. Deer use increased during states with perhaps a higher percentage felt to be summer, fall, and winter seasons on areas ferti- useful in enhancing mule deer range. lized with urea. No significant response in deer use resulted from application of ammonium sulfate. Box et al. (1966) reported that between 1950 The authors also reported that a possible shift in and 1964, 3 million acres of pinyon-juniper in 1200 spring food habits from oak browse to forbs may have projects were converted or controlled in the U.S.A. precluded selective mule deer use of the urea ferti- A large percentage of this land treatment was done lized areas. No deer density or population changes to benefit livestock. Numerous other sites have were presented. received brush control treatment. Possibly 25 percent is useful for mule deer range enhancement. Fertilization tends to increase protein content of native browse (Anderson et al. 1974). Protein The acreage under intensive grazing management content is strongly correlated with deer weights that directly benefits wildlife is difficult to deter- according to an early study by Einarsen (1946). On mine. On Bureau of Land Management administered lands burned-over ranges with interspersions of timber in in Nevada, 6 million acres are under intensive graz- northwest Oregon, mature black-tailed bucks averaged ing management systems. The BLM in Nevada estimates over 200 pounds hog-dressed weight. A second area that only a out 1%of this acreage directly benefits was characterized by a much more closed canopy with deer rang& P . In fact, many of the grazing manage- "scattered glades" and more mature browse plants with ment designs may be detrimental to mule deer habitat a much lower protein content. On this latter site mature bucks averaged less than 155 pounds. -I!Personal communication, Jim Yoakum, Bureau of Land Management, State Office. Nevada.

Deer Rcni~, Inp~~ovsmantand MuZe Deer Mmzagenrent 60 for two reasons. First, a three-year rotation, Providing greater diversity would probably improve the design of many, does not allow for the increased this carrying capacity. production and reproduction of browse species, and, second, the systems are often based on an important Other examples are available but it is still perennial grass as the key species and do not con- difficult to determine the influence of the improve- sider the importance of forbs. ment on the population. One other important factor is the fact that the literature provides little I have found no definitive figures for the num- clear-cut data on forage consumption. And, if total ber of water developments designed to improve mule consumption were known, palatability and preference deer ranges. They are probably numerous and their differences constitute additional confounding factors. absolute influence is relatively unknown. Once deer ranges are improved or before they are Over much of the range of mule deer there has improved, how do we determine that the practice will been little prescribed burning. Wildfires vary do more than just entice deer from surrounding range considerably from year to year, e.g., in Nevada, to a smaller but more desirable area? Sometimes we 38,903 acres burned in 1972 and 190,025 acres in have difficulty in doing that since it may be, in 1973 (Tueller and Lorain 1974). I know of only a some cases, difficult to attract deer onto ranges very few instances where revegetation for mule deer that they do not now use. How can a combination of was accomplished on wildfire sites. Burning should improvement and management functions provide positive be prescribed only on those sites where it has been herd changes (Fig. 1) over large areas of suitable shown or can be shown to provide benefits to mule habitat? We do this by maintaining optimum numbers deer. It can be expensive. A cost of $563 annually with good habitat, ameliorating the negative influ- for each additional buck bagged was reported in ences, and influencing deer behavior to obtain one California study (Longhurst et al. 1976). greater animal dispersion and proper use. Other benefits would have to be included to make such a practice economically feasible. Possibly there is one single factor operating in the range of mule deer in the western United The relation between forage composition and avail- States that supersedes, or in part, regulates all ability and changes in the structure of a mule deer deer range improvements and population changes. population change is not well understood. Inter- This factor is climate. There is a significant actions among habitat factors, biotic factors, and correlation between range forage productivity and population changes are complex. As one reviews the seasonal rainfall. This can, on some sites, be as Kaibab story (Rasmussen 1941; Swank 1958; Russo much as a 1200% difference in forage productivity 1964; Hungerford 1965; Caughley 19701, along with from one year to the next (Tueller and Monroe the other studies reviewed here, one is left with the 1975). In addition to this, adverse winter weather feeling that a definitive study showing how these may reduce mule deer survival and thus reduce popu- relationships work has never been accomplished. lations even with reasonable habitat conditions. Longhurst et al. (1976) reported that mean monthly Deer population changes reported in the Kaibab temperature in October, November, and December are references appear to be closely correlated with pre- postively correlated with buck harvest 1 to 3 dation, range deterioration, and range improvement. years later, and that increased precipitation in But, as Caughley (1970) seems to be asking, is there December and January is correlated with decreased a confounding relationship between these correlations buck take 1 to 3 years later. Such variations and natural changes in populations of ungulates? Do may well supersede or mask the influence of the natural self-regulating population changes, irruptive deer range improvement practice, although the or otherwise, mask the influence of improvement prac- influence of tremendous fluctuations in forage tices? These questions must be asked and answered productivity on populations has not been described. before the benefits of range improvement practices can be quantitatively described. On sane sites intense interspecific competition for forage may require that numbers of mule It seems though, that collectively, deer range deer be controlled by both sex hunts. In such improvement practices provide a combination of desir- cases, control of deer numbers is an absolutely able factors and that these factors are beneficial necessary prerequisite for the productivity and to mule deer. Artificial revegetation and good range maintenance of forage on deer range improvement or grazing management can lead to good deer range con- projects and without which the project should not dition with the requisite species diversity (Fig. 1). be attempted. Good deer range condition may be defined as a prescribed level of productivity and species composition Mule deer numbers in the Great Basin have gone Providing optimum forage and cover requirements for through an upswing and downswing (Fig. 2; Barn- mule deer. The many negative factors interact with grover et a1 1975) since the turn of the century. the beneficial management activities in a complex Has this been an irruptive population phenomenon way (Fig. 1). or are the trends related to overgrazing, secondary succession, alterations in predation, or a com- Hubbard (1962) described successful seeding of bination of factors? Surely more than one factor bitterbrush as one that will provide between 500 and is involved. Since most of the heaviest overgrazing 2200 plants per acre, depending on the site. He also of Nevada ranges occurred prior to or during the reported that it takes between 207 and 587 mature period of highest deer numbers, and since judicious bitterbrush plants to feed a 100-pound deer for one grazing, adjudication, and associated livestock cuts month. This indicates, based on bitterbrush alone, have occurred since the peak of mule deer numbers, I that the best stand would produce enough forage on suggest that the decline in recent years must be due each acre to maintain a deer for 3.7 to 10.6 months. to factors other than poor habitat. However, I am

61 Deer Range Improvement and Mule Deer Management Mule Deer Population

FIGURE 1. A preliminary diagrammetric representation of deer range improvement processes as they converge into those vectors leading to positive herd changes (to optimum numbers by age class consistent with carrying capacity). Monitor- ing of the herd or population change is of paramount importance. The arrow size represents the author's estimation of the relative importance of various factors. Dashed arrows represent negative inputs in relation to herd health, good deer range condition, and/or a tendency away from an optimum herd size. A wavy line represents a significant inverse relationship. A single solid line represents a known relationship but for which no relative importance is attached. * A positive short-term benefit but not lasting, May even have a negative influence over time.

Deer Rage Improvement and Mute Deer Management 62 YEAR

FIGURE 2. Deer harvest and tags sold in Nevada 1946-1974. (Data courtesy of Nevada Department of Fish and Game.)

63 Deer Range Improvemnt and MuZe Deer Mmagemt sure that deteriorated habitat can be indicted in some 5. Range management grazing systems on public lands instances. The greatest decline in deer harvest, and must be designed to exclude livestock from "key" presumably numbers, occurred in the early 1960's. sites during certain high competition periods. Most of the ranges had been overgrazed by, say, 1950. A reduction in livestock utilization of forbs and Has there been a 10-15 year lag before the mortality grasses on certain sites will benefit mule deer. if caused by overgrazing? At the least, the heavy They must also be designed to enhance species and livestock grazing has created and maintained the plant communities valuable for mule deer. Bal- desirable sub-climax vegetation. anced use of the deer range vegetation by both deer and livestock should be sought and then In the Great Basin many actual and potential deer enhanced as a technique for controlling succes- winter ranges have been heavily overgrazed. However, sion and maintaining good condition range. the acreage involved is considerable. Winter ranges are probably not limiting if the entire Great Basin 6. Range improvement techniques, along with live- is considered as a unit. On the other hand, it is stock management, should be concentrated on probable that summer ranges are limiting in the cen- specific plant communities with species and other ter of the Great Basin because of. their limited acre- characteristics that will respond. Less valuable age coupled with overgrazing, which has reduced desir- plant communities can be improved, but on a much able species. lower priority.

Have changes in migration routes due to freeways, 7. New and innovative techniques for range improve- urbanization, and livestock improvement practices ments to benefit mule deer must be developed (including fences) restricted herd movement and and evaluated. For example, has anyone been separated herds? If so, has the isolation increased successful in their attempts to provide arti- inbreeding in recent years, and has such resulted ficial cover with plant communities with good in a poorer vigor of individual nimals, increased forage but a lack of suitable cover? Perhaps mortality, and reduced nunbers?lf This may also result larger shrubs and trees could be planted along in reducing the benefit of a range improvement project. natural drainage ways to utilize the moisture there as well as enhancing the natural appear- I am afraid that this paper has asked more ques- ance of such a treatment. tions than it has answered. Probably one of the greatest needs is the development and use of tech- Long term studies to evaluate benefits in abso- niques for monitoring population fluctuations and lute terms should, on selected locations, accompany coupling such data to the habitat, either improved the effort to improve ranges. This will provide or natural. It is possible to summarize mule deer evidence of the benefits that will come from deer management techniques as related to range improve- range improvement practices that are now largely ment in the following manner: intuitive. A. Starker Leopold (1950) said it over 26 years ago: "We cannot continue slashing and I. There is additional need to provide additional burning the forests and overgrazing the ranges - forage on specific sites throughout the range processes which vicariously have produced some of of mule deer in the western United States. our best deer ranges in the past. Creation of deer range in the future will have to be deliberately 2. Tree and brush removal to change secondary planned as part of wildland management, with due succession to a condition favorable for mule regard for other values and uses." deer should be continued with greater emphasis on site specificity and aesthetics. Con- trolled burning will be an important tool. LITERATURE CITED

3. Revegetation projects designed for specific sites generally must provide species diver- Anderson, A. E., W. A. Snyder, and G. W. Brown. sity. This will require the seeding of 1965. Stomach content analysis related to con- grasses, forbs, and shrubs preferred by deer dition in mule deer, Guadalupe Mountains, New during certain periods of the year. Grasses Mexico. J . Wildl. Manage. 29 (2) :352-366. may provide more forage for deer than has been commonly been thought. Mule deer, while gener- Anderson, B. L., R. D. Pieper, and V. W. Howard. ally considered to be browsers, can have a 1974. Growth response and deer utilization of strong dependency (particularly on winter fertilized browse. J. Wildl. Manage. 38(3): ranges) on grasses. When Leopold (1950) writes 525-530. of the lack of deer in the mountains of California and the Great Basin early in the last century with Barngrover, L., W. Molini, and G. Tsukamoto. 1975. larger numbers reported on the fringes of the Game harvest statistics: big game, upland Sacramento Valley (historically, a bunchgrass game, migratory game birds, and furbearers range), this thought is enforced. 1974-75. Nevada Dept. of Fish and Game, Reno. Mimeo . 4. New water development, especially in the droughty parts of the mule deer range will allow the utili- Biswell, H. H., R. D. Taber, D. W. Hedrick, and zation of forage on both summer and winter ranges A. M. Schultz. 1952. Management of chamise that is not now available. brushlands for game in the north coast region of California. Calif. Fish & Game. 38(4): 453-484. -2/ Personal communication. A.L. Lesperance, Univ. of Nevada, Reno.

Deer Rmge Improvement cold Mule Deer Management Box, T. W., G. M. Van Dyne, and N. E. West. 1966. Julander, 0.. W. L. Robinette, and D. A. Jones. 1961. Syllabus on range resources of North America. Relation of summer range condition to mule deer Part IV, Pinyon-juniper ranges. Utah State productivity. J. Wildl. Manage. 25(1):54-60. Univ., Logan. Mimeo. Rpt. Kruse, W. H. 1972. Effects of wildfire on elk and Caughley, G. 1970. Eruption of ungulate populations, deer use of a ponderosa pine forest. USDA. For. with emphasis on Himalyan Thar in New Zealand. Serv. Res. Note. RM-226. 4 p. Ecology. 51(1) :53-72. Leach, H. R. 1956. Food habits of the Great Basin Cheatum, E. L., and C. W. Severinghaus. 1950. Vari- deer herds of Nevada. Calif. Fish & Game 42(4): ations in fertility of white-tailed deer related 243-308. to range conditions. N. Amer. Wildl. Conf. Trans. 15: 170-190. Leopold, A. S. 1950. Deer in relation to plant succession. Trans. 15th N. Amer. Wildl. Conf. Clary, W. P. 1975. Range management and its ecologi- pp. 571-580. cal basis in the ponderosa pine type of Arizona: The status of our knowledge. USDA For. Serv. Leopold, A., L. K. Sowls, and D. L. Spencer. 1947. Res. Pap. RM-158. 35 p. A survey of over-populated deer ranges in the United States. J. Wildl. Manage. 11:162-177. Cole, N. J. 1968. Mule deer utilization of rehabilitated Nevada rangelands. M.S. Thesis. Univ. of Longhurst, W. M., and G. E. Connolly. 1970. The Nevada, Reno. 132 p. effects of brush burning on deer. Ca1.- Nev. Wildl. pp. 139-156. Cowan, I. M. 1945. The ecological relationships of the food of the Columbian black-tailed deer, ., E. 0. Garton, H. F. Heady, and OdocoiZeus hornionus coZwnbianus (Richardson), in G. E. Connolly. 1976. The California deer the coast forest region of southern Vancouver decline and possibilities for restoration. Proc. Island, British Columbia. Ecol. Monogr. 15(2): Western Section - The Wildlife Society, Fresno. 110-139. January. (in press). 64 p.

Darling, F. F. 1937. A herd of red deer. Oxford Lyon, L. J. 1966. Problems of habitat management Univ. Press. London. 215 p. (pg. 147-153). for deer and elk in the northern forests. U.S. For. Serv. Res. Pap. INT-24. 15 p. Dasmann, W. P., and J. A. Blaisdell. 1954. Deer and forage relationships on the Lassen-Washoe Inter- Mackie, R. J. 1970. Range ecology and relations state winter deer range. Calif. Fish & Game. 40: of mule deer, elk, and cattle in the Missouri 215-234. River Breaks, Montana. Wildl. Monogr. No. 20. 77 p. DePaoli, R. L., and P. T. Tueller. 1970. Winter deer range study: Ruby-Butte study, Nevada. Nev. McColm, M. A. 1976. Mule deer population trends Agr. Exp. Sta. Mimeo. Rpt. 80 p. in northeastern Nevada and influencing factors. Unpublished paper (mimeo) presented to the joint Doman, E. R., and D. I. Rasmussen. 1944. Supple- . meeting of the Nevada Sections of The Society mental feeding of mule deer in northern Nevada. for Range Management and The Wildlife Society. J. Wildl. Manage. 8(4) :317-388. Elko. 15p.

Einarsen, A. S. 1946. Crude protein determination McCulloch, C. Y. 1973. Deer nutrition in Arizona of deer food as an applied management technique. chaparral and desert habitats. Part I: Season- N. Amer. Wildl. Conf. Trans. 11:309-312. al diets of mule and white-tailed deer. Spec. Rpt. No. 3. Arizona Fish & Game Dept. and Gibbens, R. P., and H. G. Fisser. 1970. Influence of Rocky Mtn. For. & Range Exp. Sta. pp. 1-37. grazing management systems on vegetation and wildlife habitat. Wyo. Agr. Exp. Sta. Scientific Mohler, L. L., J. H. Wampole, and E. Fichter. 1951. Rpt. No. 241. 32 p. Mule deer in Nebraska National Forest. J. Wildl. Manage. 15:129-157. Goodwin. G. A. 1975. Seasonal food habits of mule deer in southeastern Wyoming. U.S. For. Serv. Plumer, A. P., D. R. Christensen, and S. B. Monsen. Res. Note RM-287. 4 p. 1966. Highlights, results, and accomplishments of range restoration studies. Utah Dept. of Gruell. G. E., and N. J. Papez. 1963. Movements of Fish & Game. Publ. No. 67-4. mule deer in northeastern Nevada. J. Wildl. Manage. 27(3):414-422. ., and H. D. Stapley. 1959. Research in game forage restoration in Utah. Proc. Hubbard, R. 1962. The place of browse seeding in Amer. Conf. West. Assoc. of Fish & Game Comm. game range management. N. Amer. Wildl. & Nat. 30:157-166. Res. Conf. Trans. Vol. 27. pp. 392-401. Rasmussen, D. I. 1941. Biotic communities of Hungerford, C. R. 1965. Response of Kaibab mule Kaibab Plateau, Arizona. Ecol. Monogr. 3: deer to reseeded forest and meadow. N. Amer. 229-275. Wildl. and Nat. Res. Conf. Trans. p. 310.

65 Deer Rmae Inprovement and Mule Deer Maagement Regelin, W. L., and 0. C. Wallmo. 1975. Carbon black ., and A. L. Lesperance. 1970. increase snowmelt and forage availability on deer Competitive use of Nevada's range forage by winter range in Colorado. USDA For. Serv. Res. livestock and big game. Ca1.- Nev. Wildl. Note. RM-296. 4 p. p. 129-138.

Regelin, W. L., 0. C. Wallmo, J. Nagy, and D. R. Dietz. Tueller, P. T., and G. Lorain. 1974. ERTS-1 and 1974. Effect of logging on forage values for NASA high-flight imagery for measuring areas and deer in Colorado. Jour. of For. 72 (5):283-285. following secondary succession on wildfire sites. Proc., Third National Conf. on Fire. Robinette, W. L., 0. Julander, J. S. Gashwiler, and Lake Tahoe, Nevada. J. G. Smith. 1952. Winter mortality of mule deer in Utah in relation to range condition. Urness, P. J. 1966. Influence of range improvement J. Wildl. Manage. 16:289-299. practices on composition, production, and utilization of Artemisia deer winter range in central Russo, J. P. 1964. The Kaibab North deer herd, its Oregon. Ph.D. Dissertation. Oregon State Univ. history, problems, and management. Arizona Game Corvallis. 193 p. & Fish Dept. Wildl. Bull. 87. 105 p. . 1974. Deer use changes after : Segelquist, C. H. 1974. Evaluations of wildlife for- root-plowing in Arizona chaparral. USDA For. age clearings for white-tailed deer habitat man- Serv. Res. Note. RM-225. 8 p. agement in a 600-acre Arkansas Ozark enclosure. Ph.D. Dissertation. Oklahoma State Univ. 185 p. Wallmo, 0. C. 1959. Big Bend ecological survey. Tex. Game & Fish Dept. Completion Rpt. Fed. Severinghaus, C. W. 1951. A study of probability and Aid Project W-57-R-7, Job 9. 33 p. mortality of corralled deer. J. Wildl. Manage. 15(1) :73-80. . 1962. Big Bend ecological survey. Tex. Game & Fish Dept. Completion Rpt. Shaw, H. 1965. Investigation of factofs influencing Fed. Aid Project W-57-R-10. Job 9. 27 p. deer populations. p. 125-143. Wildlife Research in Arizona. 1964. Arizona Game & Fish ., W. L. Regelin, and D. W. Dept., Phoenix. 251 p. Reichert. 1972. Forage use by mule deer relative to logging in Colorado. J. Wildl. Stinson, T. 1964. An evaluation of revegetation Manage. 36 (4) :1025-1033. pilot plots established on National Forest ranges in south-central Nevada. Range Imp. Note. 9(4): Wood, J. E., T. S. Bickle, W. Evans, J. C. Germany, 8-11. and V. W. Howard, Jr. 1970. The Fort Stanton mule deer herd (some ecological and life history Swank, W. G. 1958. The mule deer in Arizona chapar- characteristics with special emphasis on the ral. Arizona Game & Fish Dept. Bull. $3. 109 p. use of water). New Mexico Agr. Exp. Sta. Bull. #567. 33 p. Taber, R. D. 1953. Studies of black-tailed deer reproduction on three chaparral cover types. Calif. Fish & Game. 39:177-186.

Tausch, R. J. 1973. Plant succession and mule deer utilization on pinyon-juniper chainings in Nevada. M.S. Thesis. Univ. of Nevada, Reno.

Teer, J. G., J. W. Thomas, and E. A. Walker. 1965. Ecology and management of white-tailed deer in the Llano Basin of Texas. The Wildl. Soc. Wildl. Monogr. 15. 62 p.

Terrel, T. L., and J. J. Spillet. 1975. Pinyon- juniper conversion: Its impact on mule deer and other wildlife. Proc., The Pinyon-juniper Ecosystems: A Symposium. Utah State Univ. May pp. 105-119.

. 1973. Mule deer use patterns as related to pinyon-juniper conversion in Utah. Ph.D. Dissertation. Utah State Univ. 187 p.

Tueller, P. T. 1976. Food habits and nutrition of mule deer on Nevada ranges. Univ. of Nevada Agr. Exp. Sta. 200 p. (manuscript in press).

. , and L. Monroe. 1975. Management guidelines for selected deer habitats in Nevada. Nevada Agr. Exp. Sta. Rpt. R-104. 185 p.

Deer Range Irqrovernent mid Mule Deer Management 66 AN OVERVIEW OF BIG GAME MANAGEMENT

Daniel A. Poole President

Wildlife Management Institute 709 Wire Building Washington, D. C. 20005

--Abstract

Mule deer are the most adaptable and widespread western ungulate. Present population depressions, whi1.e not uniform, are evident in all kinds of western ecosystems. The states' propensity to duplicate research needlessly may be using limited funds. The unsupported presumption of causes of the mule deer decline may hinder the design and conduct of research to determine root causes. A follow-up workshop of selected participants is proposed to develop new understanding about mule deer in order to improve their management throughout the West .

I commend Utah State University's College of wildlife viewers. A major decline in numbers of any Natural Resources, the Natural Resources Alumni Asso- species of this importance affects the casual viewer, ciation, and the program committee for scheduling the hunter, and diverse economic elements, as well. this badly needed symposium on the major problem of The effects go beyond deer because they invariably mule deer decline. It is especially fitting that this result in declining income for the state wildlife symposium is being held in Utah, a state long known department and curtailment of management programs for the vast amount of recreation provided by mule for other species. deer to hunters and nonhunters alike. I will make one disclaimer. Please bear with Mule deer are so much a part of the natural me if there is some repetition of what you heard scene here that it is proper that Utah should be one this afternoon or what you believe you may hear to- of the first to formally address the problem of de- morrow. Preparing a dinner talk is difficult with- clining deer numbers and to begin to coordinate ef- out an opportunity to read the technical papers of forts to determine its reasons and the opportunities the symposium. Therefore, I am limiting my remarks for its correction. I also commend all those who primarily to the problem in its larger perspective helped organize this worthwhile endeavor as well as as seen by our staff. the participants, speakers and nonspeakers alike. A problem of this geographical magnitude needs all the I don't need to tell you that the management of helping hands that can be mustered into service. mule deer is, has been, and always will be a complex undertaking. Although present declines are not uni- I am gratified by this opportunity to be with versal in time or place, they do cut across the en- you. The Wildlife Management Institute is interested tire range of the species in the West. Literature in all wildlife and land management in North America. reviews bear this out, and some recent papers detail We have especially strong ties with the West and the it extensively. vast acreage of public lands that provide manageable habitat for some of the finest wildlife in the nation. These declines include all kinds of ecosystems, The Institute was among the first, if not the first, from desert sagebrush to high mountains. There is private organization, to take an interest in and ex- no simple answer to any ecosystem problem. Deer, press public cmcerns for what were then only local- like grass, shrubs, trees, the other plants and the ized declines of mule deer herds in a few states. It hundreds of vertebrates, are part of an interrelated was because of this long-term interest that I quickly system. There is no one answer or reason for changes accepted the invitation to speak here tonight. I am in the numbers of any species. These species are a grateful for the opportunity to share with you our product of their habitat and they must be related to concerns for the present and our hopes for the future changes in the total habitat wherever located and of the mule deer. however caused. The fact that these changes in mule deer numbers have been and are occurring in a wide The Rocky Mountain mule deer is the most adapt- range of different habitats is indicative to us of able and widespread western ungulate. Mule deer are total and general changes in the .,lany western eco- a part of the western scene. They provide bread and systems. butter recreation for most of the more than three million hunters in the eleven western states, as well As the major cosponsor of the recent Bicenten-- as incalculable pleasure to many more millions of nial meeting of the North American Wildlife and

67 An Overview of Big Gcrme Management Natural Resources Conference, the Institute prepared compatible arrangement between commodity production and published an educational bulletin entitled and wildlife. American Landscape: 1776-1976, Two Centuries of Change. It shows many of the changes that occurred Dr. Robert H. Giles saw this in 1962, (Giles throughout the nation in the last 200 years. I call 1962) when he wrote: your attention to vegetative changes for the better that are shown in some of the before-and-after pic- A great hindrance to the advancement of tures. There have been major habitat changes in his- a coordinated use program is failure to toric times -- yes, during the professional lives of imaginatively use existing knowledge of many of us in this room. These changes affect every forest wildlife needs and to develop these living thing on the land. And changes continue to needs into management directives. . . occur. Certainly, research is needed, but while waiting, we need to work with what we The Institute has several major concerns about have. Work to be done is not for the the management of mule deer. We are not too solici- research staff, but for the management tous about the detailed management techniques used team who sees the needs, recognizes limi- by the states. But we are concerned with the general tations, and can make modifications to effort and thrust with which that management is accom- fit existing conditions. The applied plished and in some of the problem we see in that ecologist needs to start applying, not management direction. We do not rank our concerns in waiting for handouts from research per- any particular order because all are interrelated. sonnel who have enough problem of their And all are primarily based on the knowledge availa- own. Managers must then share information ble and how that knowledge is used in management. on the results of their efforts with their colleagues. If we accept the assumptions that funds for wildlife management are finite, usually inadequate, and Another concern is lack of knowledge. I am cer- always hard to come by, one of our concerns will be tain you all know of specific pieces of information placed in perspective. That concern is parochialism you believe are needed to adequately manage mule in management and research on mule deer. We have re- deer. Very large pieces of information are needed peatedly witnessed the dampening influence that state to help protect and enhance wildlife habitat. With- boundaries have on the use that is made of research out question, there are gaps in our knowledge of mule data by some administrators. Simply because some- deer and their specific habitat requirements and of thing is learned beyond the boundaries of a state the animal's reactions to changes in the ecosystem. should not make it suspect. Nor does it mean that At best, this knowledge, when acquired, may enable such knowledge should be rejected out of hand because us to increase deer numbers; at worst, it will en- of the attitude that "what affects neighboring states able us to make better trade-offs when habitat is does not apply here." Such an attitude wastes fund- manipulated for commodity production. ing and delays development of sound management programs. Some steps have been taken to reduce this Coincidental with this lack of knowledge is a parochialism, such as the workshop program of the sometimes overabundance of other knowledge. Too Western Association. But that program has not done many states have conducted nearly identical research the job that needs to be done, and must be done, to on nearly identical problem for many years, when bring successful deer management into the third cen- one or two projects would have yielded the knowledge tury of this nation's history. needed for all to manage the animals. Such duplica- tion is a direct result of parochialism. It uses Tunnel vision is another major concern. This funds that could be better spent for filling knowl- shows up in the way some states attempt to determine edge gaps. A hard look should be taken at this du- the causes of mule deer declines. Let me illustrate. plication by all concerned. A major deer area has undergone a serious population decline. A research program is initiated to find Analysis of wildlife problems requires some out why. State people say, in effect, "the decline knowledge of how each participant views the problems. may be due to changed livestock use, or to succession- How do wildlife managers in the intermountain area, al changes in the vegetation, or to overhunting, or particularly Utah, view the problem of deer decline? to predators. But it is probably due to predators, I could go through the many cubic feet of agency re- therefore we will research predation and ignore the ports, memoranda, research findings, and harvest others." Locking in on a predetermined cause to the regulations. But in this symposium, the work has virtual exclusion of others is a disservice both to already been done for me by the program committee. scientific wildlife management and to the future of The committee has indicated the importance of the a magnificent wildlife species. many factors affecting mule deer by the amount of program time allocated to each. Another of our concerns is the nonapplication of existing knowledge. The public land manager is There are seven hours of subject matter on mule changing the public lands daily. The chain saws are deer decline, excluding the introduction, the sym- buzzing, range drills are seeding, and tractors are posium summary, and my time tonight. Broken down uprooting juniper and pinyon. The land manager asks in broad categories, I find two hours are devoted for help in limiting wildlife damage. The wildlife to various problems in habitat. This is 29 percent manager answers, "I do not have the data; I do not of the total. I find that predation and other mor- have the research." Yet there is a wealth of data talities cover another 21 percent with 1-112 hours. available, some of it in summary form, and some of it Populations, including census and harvest regula- in professional judgments that can be used to estab- tions, are important, with 2 hours or 29 percent of lish land management guidelines that will make a more the time devoted to them. Disease factors, nutri-

An Overview of Big Gmne Management tion, and history each have a 30-minute time segment, that provided its needs when its population was at a or 7 percent each of the total program. All of the peak. Thus, it may not be able to rebound with an- topics slated for discussion are important. My only other irruption. concern is the fact that predation and mortality factors are only a part of the mule deer's environment, New, complex, and important relationships of and often affect the animals for but a short time a ungulates and cover are being developed and published. year. Yet they are given almost equal weight with Some of you may have attended the elk-logging sym- total habitat. posium last winter at the University of Idaho. If you did not, I certainly recommend you study the While this is not a scientific paper, I have transactions of that symposium when available; par- sought the reactions of a number of younger research ticularly the papers relating to escape and thermal people in both range and wildlife management and have cover. The Forest Service, in cooperation with read some recent papers regarding wildlife and land other agencies, is doing good work on these subjects management. I would like to share with you some of in the Pacific Northwest. Region 6 is preparing in- the factors that I feel are important in putting the teragency guidelines for wildlife cover in the mule deer in perspective. Douglas fir region. The Pacific Northwest Forest and Range Experiment Station soon will publish, in I think we all know that mule deer are succes- book form, interagency guidelines for maintaining sional, and are products of successional rather than and enhancing wildlife habitat in the Blue Mountains climax vegetation. This closely relates them to com- of Oregon and Washington. These "cook book" aP- modity land management of forestry and range live- proaches will tell the land manager what he must do stock, both of which tend to create successional vege- for each class of wildlife, and what the effects tation. Deer evolved with other animals, particularly will be if he neglects wildlife. Such data, both the mountain sheep. Is it not possible, then, that scientific and judgmental, can be readily transposed deer require other animals acting on the vegetation to meet conditions in other parts of the West, par- to maintain the needed vegetative succession? For ticularly for large ungulate habitat. a number of years, progressive people in range and wildlife management in both the universities and the I am especially impressed with the new concepts agencies have discussed this. Some point out that that have been developed concerning energy and ener- they foresee the day when livestock will be an inte- gy requirements and their relations with cover and gral management tool for vegetation manipulation on land management. These subjects and relations are areas where big game has a primary use. Some even of such importance that, if they are not fully foresee the day when livestock operators will be covered at this symposium, then the wildlife scien- paid, or otherwise subsidized, to graze deer winter tists at Utah State University should prepare ab- ranges beyond the point that a prudent livestock oper- stracts and bibliographies for the wildlife mana- ator would graze them. Not to graze to the detriment gers in all agencies in this region. Some of this of the soil and water, but rather as a manipulative material must be transferred from livestock use. tool to maintain or reach certain desirable succes- Outstanding work has been done by Dr. Cook at this sional vegetative levels for big game. university. Other work, such as that on white- tailed deer by Moen, can be transposed to formulate We note that mule deer numbers and sheep numbers new concepts for solving questions in mule deer follow a similar curve: as sheep decline, mule deer habitat needs (Moen 1973). also decline. Mule deer are down, sheep are down. Is there a vegetative cause and effect? A hypothetical example will be of interest. In work on Utah domestic livestock, Cook found that Predation research, much of it excellent, is gestating females required 830 kilo-calories per still research devoted to but a small portion of the pound of forage in digestible energy. Yet some total ecosystem. If predation is the factor that desert ranges furnish only 803 kilo-calories (Cook). some obviously believe, then research should be ex- The question posed by a range manager was this: panded to include the full array of predator-prey could such a shortage of 26 kilo-calories be offset relationships and their ties with successional changes. by better protection and thermal cover on deer win- Why, in much of the West, do we not have the great ter ranges? Would such protection reduce the energy irruptions of jack rabbits that we had ten to thirty output and enable not only successful survival but years ago? Could it be because, like deer, the jack successful parturition? needs certain successional stages to have a peak population? What are the relations between white- These complex relationships should he placed tailed and black-tailed jack rabbits as vegetation in a proper wildlife management conceptual framework moves to higher successional stages? and data accumulated to reconcile the entire range management energy and cover interrelations. Such To the trained eyes of range and wildlife mana- habitat changes as encroachment of timber on moun- gers, there are changes underway. Western forests tain meadows may reduce the stored energy the ani- and ranges show general and sometimes dramatic vege- mals take to the winter range. Changes in fall tative changes toward climax vegetation. What are ranges from fall green grasses to fall dormant gras- the implications of this to deer populations? I hear ses may reduce the energy intake just enough to be some occasional discussion, but there is little gen- a significant factor in the mule deer declines, eral consideration of the fact that the agencies now when coupled with minor losses of thermal cover. I are doing a significantly better job of range manage- pose these as questions that will require intensive ment over much of the West. This is bound to affect interdisciplinary research to resolve. the vegetation deer require. Under such conditions, a mule deer herd, reduced by the catastrophe of There is another activity underway of vital im several bad winters, may not have the same habitat portance to all wildlife on public lands. I refer

An Overview of Big Game Management to the requirements of the environmental acts and will prepare a shopping list of research needs and Federal court decisions. Mule deer are so much a make recommendations for multi-state and multi- product of public lads that the environmental state- agency projects. The goal would be to attain re- ments now required on Forest Service unit plans and search efficiency and knowledge needed for improved environmental statements just starting on Bureau of management. Land Management grazing systems are the best chance the wildlife manager and state wildlife agencies ever The published results of such a brain-storming have had for significant input into the federal land session would be useful in putting mule deer under planning process and the effect of those plans on an ecosystem management concept, hopefully pointing wildlife. The Institute views them in this light, out and starting to solve some of the decline prob- and we urge you to comment, and comment strongly, on lems. At the least, we will be able to recognize every one of these documents. The plans will not the effects of land management activities and ar- lock resource management into cement forever, but you range rational trade-offs more beneficial to wildlife know how hard it is to turn something around once the than we presently are able to accomplish. footing has been poured. Get into these now. It's your opportunity to do something positive in develop- I cannot overemphasize the acute need for im- ing better land management programs. proving our capability in this regard. In Washing- ton, we deal regularly with issues involving the As a small, private conservation organization, management direction of two large holdings that are the Institute seeks to help improve wildlife condi- the domain of the mule deer in much of the West -- tions in many ways. Often, one of the best actions the national forests administered by the U. S. For- we can take to help resolve a problem is to serve as est Service and the national resource lands adminis- a starter or a catalyst for a beginning. That I now tered by the Bureau of Land Management. hro sepa- propose. rate legislative proposals dealing with the lands administered by these major agencies are pending in We believe that a follow-up workshop to survey Congress at this moment. How mule deer or any pub- the state of the art in mule deer management and the lic lands wildlife will fare under the legislation strengths and weaknesses of mule deer habitat re- finally approved by Congress will depend in large search is an essential next step. The Institute degree on how well our profession can demonstrate would be willing to organize or to assist in the or- the direct link between permitted management activi- ganization of such a meeting. The workshop would be ties and the needs of such wildlife. The more con- patterned after the successful Wild Sheep Workshop, cise and persuasive information that can be pulled sponsored in 1974 by the Boone and Crockett Club, together for any species of wildlife, the more National Audubon Society and the Institute. It would effective are conservationists' representations to be structured to assemble the best minds on the sub- Congress. The same holds for situations that are ject in a setting conducive to deliberation and dis- encountered within state. cussion for the purpose of producing a summary publication on the mule deer. It would be a working docu- I thank you for the privilege of addressing ment, useful to administrators, managers and re- this distinguished group. Let's not forget our searchers alike in identifying those paths that most honored guest -- the Rocky Mountain mule deer. should be followed to obtain needed new understanding Our purpose these two days is to help him, and to about mule deer and to improve their management do that we must develop the new concepts and new throughout the West. The Institute is committed to programs he needs. this goal inasmuch as a new book on mule deer is being readied for publication in our wildlife monograph series.

As we conceive it, the meeting would not be solely for agency directors and the chiefs of research and management. It would be invitational, with participants drawn from universities and colleges and state and federal agencies. Young people would be included, because we want to obtain the most current wildlife thinking. We propose to invite people from the mid-range research hierarchy, at beginning and middle management and administrative levels, as well as some field researchers. Wildlife managers would not predominate. We would want and need strong par- ticipation from range and forest management research interests.

The participants will be assigned five major tasks. The first will be to divide the West into comparable habitat units where there is no question that research findings will be applicable within the unit. Two -- they will determine what knowledge is available for each of the habitat units. Three -- they will determine what additional knowledge is needed to properly manage mule deer in each habitat unit. Four -- they will determine what duplications in research are now going on and prepare recommendations for consolidation or elimination. Five -- they

An Overview of Big Game Mmagement 70 MULE DEER NUTRITION AND PLANT UTILIZATION

Donald R. Dietz Fish and Wildlife Biologist Office of Biological Service, Region 6 U.S. Fish and Wildlife Service Grand Junction. Colorado 81501

Julius G. Nagy Associate Professor Department of Fishery and Wildlife Biology Colorado State University Port Collins, Colorado 80521

Abstract

Deer nutrition and range plant utilization are probably both directly and indirectly associated with the possible mule deer decline. The direct effect of malnutrition is starvation: the indirect effects are many and varied, such as susceptability to disease and parasites, low fawn production and inability to withstand environmental stress. Deer ranges are dynamic; the vigor and productivity of important mule deer food species are partially contingent upon the stage of plant succession. Many important browse plant communities are (1) the result of past site disturbances, (2) near the end of their lifespan and (3) may not be replaced because present land management factors tend to prevent recurrence of important disturbance factors such as fire, intensive browsing and grazing, and severe timber harvesting. Deer nutrition is a function of plant nutritional production, deer feeding habits, and the relation of nutrient intake and digestibility to deer physiological requirements. Digestion in the rumen is a function of the microbial population which can be greatly inhibited by the levels of volatile oils contained by various plant species.

The seasonal deer diet varies from a growth promoting (high protein and phosphorous) diet in spring to a fattening (high carbohydrate, fat, and energy) .diet in fall to a maintenance (low protein and energy) diet in winter. Seasonal use of plant types varies from high grass use in spring, high forb use in summer and fall to high shrub use in winter. Variability among seasons, deer ranges and years is exceedingly high. The presence of volatile oils in evergreen and semi-evergreen shrubs such as sagebrush. juniper and pine can greatly affect species use by deer. Land management practices, vegetation type conversion and revegetation programs should consider the selection of low volatile oil bearing plants for protection, enhancement and reestablishment.

Deer nutrition discussions often review and re- in the life of the mule deer for meeting nutritive port on the chemical composition and digestibility requirements for various physiological states such of their staple food plants without relating these as growth, lactation, reproduction and winter Parameters to either the nutritional requirements or maintenance. A brief rationale illuminating the to the changing diet of deer. We propose to alter role nutrition may play in the possible mule deer that scheme by following the diet of a mule deer decline in the west is presented in the following herd through their yearly cycle of activities. Thus section. we will discuss plant species and groups important

71 Mule Deer Nutrition and PZant UtiLiaatim Deer Nutrition - An Overview selectively used and coupled with correct land, human, and animal management practices. The fate of mule deer throughout the west is intrinsically entwined with the year-long nutritive While deer population fluctuations are un- regime of their food species. The suspected decline doubtedly partially dependent upon nutritional of mule deer populations may be due in part to both parameters, deer behavior mechanisms may play an direct and indirect nutritional factors. The direct even more important part. It has been proposed by effect of malnutrition is starvation, however, the Peterle (1975) that white-tailed deer populations indirect effects work through such vectors as para- may be self-regulatory in that population eruptions sites, disease, weakness and susceptibility to do not occur on areas where they are in balance predation, failure to conceive, reabsorption of with their food supply, such as on some islands, fetuses, inability to nourish offspring and impaired national parks, etc. Eruptions occur only after or decreased ability to digest high roughage feeds some disturbance creates a large surplus of food. such as hay and/or new spring plant growth. Unfortunately the herd is usually still increasing long after the balance between deer and food has Starvation may result from not only lack of passed. A yo-yo effect is then often seen until a food but also because of inadequate levels of pro- new temporal balance is achieved. Possibly mule tein and phosphorous and/or coupled with the inges- deer have a similar sociobiology. tion of toxic materials such as essential or volatile oils contained in sagebrush, juniper and other ever- Deer are not super-ruminants but rather pre- greens or semi-evergreens. cise in their dietary needs. Their relatively small rumen is not well adapted to coarse, low If, as several biologists propose including quality roughages (Short, 1966, 1969). Given free Julander (1962), the decline of mule deer is a choice they will select the more nutritious twig result of a gradual change in habitat, then malnutri- tips and young leaves. tion may be the result of too many deer being forced to eat too much material for too long a time, which Deer nutrition is really rumen nutrition is detrimental to their vital physiological pro- since digestion is carried on in that part of the cesses. We are referring, principally, to undue ruminant stomach by bacteria and protozoa. To dependence upon sagebrush, juniper, pine and other remain healthy and carry on all their physiological species which contain high levels of volatile oils. demands required for body maintenance, growth, and reproduction, deer must supply the rumen with ade- While the rationale for the change in mule deer quate nutritive levels. Rumen microorganisms need habitat is not within the provinces of this paper, it nitrogen and certain other minerals and vitamins could be as simple as a gradual change in plant to breakdown and metabolize carbohydrates. Most community structure due to plant succession. There of the energy available to deer results from the are only a limited number of plants which meet the breakdown of carbohydrates mainly sugars, cellulose, dietary requirements of deer in winter. Most are and hemicellulose by rumen microorganisms. The deciduous shrubs such as bitterbrush, mountain- most important end products of these fermentations mahogany and chokecherry. Others mostly evergreens are the volatile fatty acids (VFA) such as acetic, or semi-evergreens contain more than adequate proprionic, butyric, valeric, and isovaleric amounts of important nutrients, but also contain (Annison and Lewis, 1959; Church, 1969). These volatile oils which can impair rumen function. VFA's are absorbed mainly through the rumen wall and supply approximately 50-70 percent of the Deer ranges are dynamic. Important deciduous energy requirements of the host animal (Annison shrubs are rather short lived, 60-70 years according and Lewis, 1959). These acids must be produced in to Roughton, (19721, reproduce by seed such as both adequate amounts and in the proper proportion bitterbrush and mountainmahogany or by root sproutiqg for digestive and other body processes to function such as serviceberry and chokecherry, and cannot properly. withstand heavy browsing indefinitely (Shepherd, 1971). Many shrub ranges probably resulted from a Most of the concentrates such as proteins, severe disturbance. In the case of bitterbrush and minerals, fats, vitamins and soluble carbohydrates mountainmahogany this was possibly because heavy are contained within the plant cell. The cell livestock grazing reduced the competition from grass wall is composed of cellulose, hemi-cellulose and and forb species and created a site with growing other structural carbohydrates. During the spring space for new seedlings. Several other conditions and early summer the rumen microorganisms can had to occur concurrently: these were low livestock, easily breakdown the plant cell wall and most of deer and rodent numbers; a good seed crop on the this material is metabolized. After the autumnal remnant shrubs; and several good precipitation years period the cell wall becomes increasingly lignified. in succession. These conditions are not likely to This lignin complex is not digestible and thus in- occur again under present land management practices. creasingly less of the cell wall and contents can As the old shrubs die it is not likely they will be be digested. Not only do plants contain less of replaced. the important nutrients during the plant dormant season but they are also less readily available The root sprouting shrubs offer more promise. for assimilation. They undoubtly became abundant originally following fire, overgrazing, or logging. The natural succes- Spring - Early Summer Period sion is likely toward a grassland or toward a mature forest. Neither is a good habitat for mule deer. The spring - early summer period is the time The match, axe or domestic herbivore are management of best feeding conditions for mule deer in much tools for these situations, but they have to be of their range. Not only are summer ranges more

Mule Deer Nutrition and PZmt UtiZization heavy producers of dry matter, they also provide a (A. spicatum) according to Kufeld 5 & (1973). larger variety of plants having higher nutrient con- These authors also reported heavy use on brome tent, and plants which are more digestible. Even on (xsspp.), mutton bluegrass (Poa fandleriana), non-migratory mule deer range shrubs, forbs and Sandberg bluegrass (P. secunda), and needle and grasses are at their peak levels of the most impor- thread (Stipa comata). Moderate use was made of tant nutrients during the early growth phenological many genera including Dactylis, Danthonia, Festuca, stage (Dietz, 1962). Koeleria, Oryzopsis and Phleum. Nutrition Requirements: Spring - Summer Forbs reported to be receiving heavy spring use by mule deer according to Kufeld (1973) The nutritional requirements of mule deer are sulfur wildbuckwheat (Eriogonum umbellatum), during the spring period vary according to age, sex, cream peanine (Lath +us ochroleucus), Lomatium and physiological requirement. A dry doe would (Lomatiums spp .-tilla newberr i) , require lower protein, phosphorous, and energy and mountain deathcamus (Zigade- levels than either pregnant or lactating animals. are a great many species of forbs which are rated While 14-16 percent crude protein would be desirable moderate as to spring food items. for young animals and lactating females, barren does could get by on 12 percent or less. The need is for One of the shrubs and trees reported to be nitrogen rather than protein since these ruminants subject to heavy spring use is big sagebrush can synthesize all of the amino acids required by (Artemisia tridentata). This would presumably be the host. very early spring use. Heavy use has been reported on all the mountainmahoganies (Cercocarpus Possibly as important as protein is phosphor- spp.) , Mexican cliffrose (Cowania mexicana) , Utah ous, usually in short supply on western mule deer juniper (Juniperus utahensis), and creeping juniper range. Again as with protein, young growing animals, (J. horizontalis), western snowberry (Symphori- pregnant and lactating does, and mature bucks all carpos occidentalis) , and small soapweed (Yucca have heavy demands for phosphorous to satisfy glauca). A great many species of shrubs are ranked physiological requirements. Optimum requirements as moderate in use. for these classes of mule deer are probably in excess of that found on most spring ranges. Over Nutritive Levels of Plants in Spring - Early Summer 0.50 percent phosphorous would be desirable in the spring diet of mule deer, while any value less than The new growth in spring of leaves and stems 0.17 percent would probably result in some adverse of grasses, forbs, shrubs and trees often equal or effect on body function. Vitamins are usually in exceed good grade alfalfa hay in such important ample supply during the vigorous plant growth period nutrients as protein and phosphorous. Levels of of spring, especially carotene, the precursor of 20 or more percent protein and 0.30 percent phos- vitamin A. phorous are not uncommon (Urness, 1973). Forbs are an especially good source of these two mineral A serious problem which may occur on spring components. Annual grasses such as cheatgrass mule deer ranges is the high water content of new (Bromus tectorum) also rate very high in protein growth especially of young grass and forb leaves and phosphorous during early spring growth. but also in new growth twigs and leaves of shrubs and trees. The relative small rumen-reticulum of Carbohydrates and true fats are low in all mule deer, especially immature animals, can hold plant types during this period, hence gross energy only limited amounts of plant material. If 90 per- intake may be limited due to low volume capacity cent of this is water, as frequently happens in new of deer rumens and high water content of ingesta. grass growth, the deer simply cannot ingest enough material to meet total dry matter and especially Summer - Early Fall Period carbohydrate and energy demands (Dietz, 1970). Thus, mule deer coming off a hard winter where a prolonged As the summer progresses and plant growth sagebrush-juniper diet has resulted in large body reaches maturity as characterized by full leaf and weight losses plus probably some changes in the complete stem elongation in shrubs and trees and rumen flora will tend to gorge on the lush spring the appearance of the hard dough stage in grasses growth of immature grasses. The sudden switch from or forbs, the mule deer diet switches from a grow- hard browse to lush greens results in immediate ing ration to a fattening ration. stress through scours, rumen function impairment, and frequently secondary infection in the digestive Nutritive Requirements: Summer - Early Fall tract. The combined impact may often be fatal. Protein and phosphorous requirements decline Spring - Early Summer Diet for adult deer during summer and early fall but remain high for growing fawns. While adult deer Kufeld cg (1973) summarized the results of would probably do well on a level of 10-12 percent 99 food habit studies conducted on mule deer ranges protein at this period, young growing animals in the western United States and Canada. They would perform better on a level above this amount. reported the spring diet of mule deer is highly Phosphorous levels of feeds for mule deer should varied with location and in some cases even years. probably exceed 0.18 percent at this period but The bluegrasses (kspp.) are highly preferred on many plants do not sustain this high of a level many meadows used by mule deer as soon as new growth into the late summer - early fall period. Energy becomes available. Important grass species in the demands are usually easily met at this season. spring diet of mule deer are wheatgrasses especially crested (Agropyrum cristatum) and bluebunch

73 Mule Deer Nutrition and Plant Utilization Summer - Early Fall Diet also in nutrient levels to around 8-10 percent protein, 0.15-0.30 percent phosphorous and 4.4-4.8 As plant species mature and animals prepare for kcal/g. gross energy. the winter season, diet preferences change; Mule deer begin their trek to transitional ranges during Carbohydrate content including cellulose and this period which also accelerates the change in lignin increase along with the fats and oils found dietary items. in ether extract or crude fat. True fat content is usually at its peak during late summer - early Grasses comprise a small proportion of the fall and gross energy intake reaches a seasonal summer diet - generally anywhere from 0 to 22 per- maximum. Digestibility is retarded somewhat by cent of the diet (Kufeld %& 1973). No grass or increased lignification. sedge species were rated as heavy use feeds during summer, however, several were rated moderate in use Late Fall - Winter Period class. These were smooth brome (Bromus inermis), sedges (- spp.), orchardgrass (Dactylis Mule deer food values change considerably glomerata), regal rush (Juncus regelii), and June- from a fattening diet in early fall to a mainte- grass (Koeleria cristata). nance diet from late fall through early spring. With onset of leaf-fall, shrubs and trees provide Forbs become very important in the summer - at best only marginal levels of important nutri- early fall diet of mule deer especially on some ents. Grasses and forbs dry and wither or shatter game ranges. Kufeld and associates in their report providing even poorer nutrient levels. Evergreen gave ranges of 3 to 77 percent of the diet in and semi-evergreen species hold up better in summer and from 2 to 78 percent in fall have been nutritive composition but many contain tannins and reported for forbs. Some heavy use forbs were essential oils which may inhibit digestibility. dogbane (Apocynum spp.), Pacific aster (Aster Not only are nutrient levels low at this season, chilensis), Wyoming indianpaintbrush (Castilleja but also lignification of the cell wall depresses linariaefolia), hairy goldaster (Chrysopsis villosa), digestibility by deer rumen microorganisms. Fremont geranium (Geranium fremontii), American licorice (Glycyrrhiza lepidota), cream peanine Nutritive Requirements: Late Fall - Winter (Lathyrus ochroleucus), alfalfa medic (Medicago sativa), yellow sweetclover (Melilotus officinalis), Deer need access to a total dry matter intake dandelion (Taraxacum ceratophorum), clover (Trifo- of 2.35 lbs. per hundredweight of body mass for lium spp.) and many others. maintenance according to Carhart (1954) and Nichol (1938). French gt!t (1955) recommended 3 to 4 Several forbs were rated as heavy deer use lbs./100 lb. deer. Deer probably need at least species in the fall. These were longleaf sagewort 4,800 kcal of dry matter per hundredweight, (Artemisia longifolia), hairy goldaster, barbey however, French %& (1955) recommended 6,300 larkspur (Delphinum barbeyi), Wright buckwheat kcal per hundredweight of deer. Protein probably (Eriogonum wri~htii), silvery lupine (Lupinus should not go much below 8 percent of the diet. argenteus), alfalfa medic, yellow sweetclover, Cook (1971) recommended about 4.5 percent digest- toadflax penstemon (Penstemon linarioides), and ible protein for herbivores for gestation. French wildspikenard falsesolomonseal (Smilacina racemosa). --et a1 (1955) reported deer need a minimum of 0.25 percent phosphorous for maintenance. However, Heavily used shrub and tree species in summer based on nutritive requirements for cattle and are white fir, Siberian peashrub, curlleaf and true sheep, mule deer should be able to survive on mountainmahogany, redosier dogwood, cotoneaster, around 0.16 percent which is the level given by Russian olive, Wright silktassel, honeysuckle, Cook (1971) as the gestation requirement for herb- desert peachbush, desert and antelope bitterbrush, ivores. Cook also suggested herbivores require Gambel and wavyleaf oak, smooth and skunkbush sumac, about 1.6 to 1.7 mgllb. of carotene for gestation. willows, silver buffaloberry and blueberries. In the fall those most heavily used are: inland Late Fall - Winter Diet ceanothus, curlleaf mountainmahogany, Lewis mock- orenge, aspen, desert and antelope bitterbrush, The onset of winter results in a decreased Gambel and wavyleaf oak, skunkbush sumac, willows, dependence upon grass and forb species. Kufeld and blueberries. --et a1 (1973) reported heavy use on only one species of grass during winter -- crested wheatgrass. Nutritive Levels of Plants in Summer and Early Fall These authors reported moderate use on some species of other wheatgrasses as well as on brome, fescue, Protein, phosphorous, and carotene levels de- timothy, and bluegrass. Heavy forb use was re- cline as plants mature in summer, but remain fairly ported on only Newberry cinquefoil and Wyeth high until leaf color change and subsequently leaf- wildbuckwheat. fall. The leaves of shrubs range from about 10-15 percent crude protein, while stems are much lower -- Heavy mule deer use was found in winter on 4-9 percent. Phosphorous levels range from around Rockymountain maple (Acer glabrum), silver sage- 0.20-0.40 percent in leaves to 0.12-0.20 percent brush (Artemesia cana), and big sagebrush, most for stems. Gross energy averages about 4.8 kcal/g. species of mountainmahogany, Mexican cliffrose in leaves to 4.7 kcal/g. in stems. (Cowania mexicana) , green ephredra (Ephedra viridis), creeping juniper, myrtle pachistima Grasses may decrease to 6-8 percent crude pro- (Pachistima myrsinites), both desert and antelope tein and 0.10-0.15 percent phosphorous but still bitterbrush and yucca. Many others were rated contain 4.0-4.2 kcallg. gross energy. Forbs decrease moderate in use by Kufeld (1973).

Mule Deer Nutrition und PZmt Utilization 74 In the Black Hills, heavy winter use was the importance of these compounds as defense found on old man's beard (espp.), chokecherry mechanisms of plants against overutilization, for (Prunus virginiana), ponderosa pine (Pinus onderosa), example, fir, spruce, pine, etc. Others, such as common juniper (Juniperus communis) , the wide variety of sagebrush and juniper species, (Arctostaphylos uva-ursi), and low Oregongrape- deserve our attention in mule deer management , (Berberis repens) (Schneeweis et &, 1972). because these plants are considered important, especially during winter, as deer forage and cover. Nutrient Levels of Plants in Winter In general, volatile oils possess antibacter- Crude protein content of deciduous shrub ial properties; and, therefore, knowledge of these annual growth decline from the 10 to 12 percent properties is important in the nutrition of rumi- range to 5 to 9 percent range with leaf-fall. In a nant animals such as sheep, cattle, deer, and elk. study in the Black Hills, only the winter twigs of It is a well-known fact that for proper digestion, chokecherry of shrubs tested contained over 9 per- ruminants must rely on their rumen microbial cent protein (Dietz, 1971). Studies in Colorado populations. Any substance, such as the volatile showed only big sagebrush (a semi-evergreen) of the oils, which might interfere with proper function- common important shrub species contained over 10 ing of the rumen microorganism might ultimately percent crude protein during the winter period reduce the energy supply for the ruminant host. (Dietz etg, 1962). Such important winter browse species as bitterbrush, true mountainmahogany, and The antimicrobial activities of volatile oils rabbitbrush supply above adequate levels (7-9 per- have been demonstrated on rumen microorganisms &I cent) of crude protein. Shrubs which generally vitro (Nagy, &, 1964; Nagy, &, 1967; Oh, contain less than 7 percent crude protein (possibly --et al, 1968; Longhurst, % &, 1968; Nagy, % &, the critical level) are Gambel oak, wavyleaf oak 1968). These works showed that the volatile oils (Quercus undulata), snowberry (Symphoricarpus spp.), of different plant species may exert different rose (Rosa spp.), aspen, and many others. degrees of antimicrobial action. As an example. Figure 1 shows that volatile oils obtained from Grasses and forbs are normally deficient in Artemisia tridentata are more inhibitory than crude protein in winter often dropping down to 3 or those obtained from Artemisia nova. It should be 4 percent. Evergreen and semi-evergreen shrubs mentioned also that Artemisia nova contains con- such as juniper, sagebrush, or rabbitbrush retain siderably less volatile oils (1.4 percent on dry higher levels of phosphorous during the winter sea- matter basis) than Artemisia tridentata (2.5 person than do shrubs such as bitterbrush, mountain- cent). For this reason, on gram per gram basis mahogany, serviceberry, and Gambel oak. All of the A. nova is less inhibitory than A. tridentata. latter are deciduous shrubs and contain less than Indeed, observations generally agree that A. nova the recommended 0.16 percent phosphorous thought is preferred over A. tridentata by deer and to be minimal. domestic sheep. One should be aware of the fact, however, that the volatile oil content of the Grasses and forbs are definitely deficient in species will depend also on site characteristics phosphorous during winter. Only those that produce and are subject to seasonal variations. Figure 2 a green basal rosette that persists late into the shows that small concentrations of volatile oils fall and early winter supply more than token have no or very little impact on rumen micro- amounts of phosphorous. Species such as tufted organisms. At higher concentrations, however, hairgrass (Deschampsia caespitose) may contain only their inhibitory action accelerates. This activ- about 0.05 percent phosphorous even in late summer ity has been demonstrated in vitro with a rumen or early fall. fistulated goat. When increasing amounts of sagebrush volatile oils were administered daily Grasses are reported by Cook (1971) to be good through the rumen fistula, the goat, receiving a sources of carbohydrates and energy for herbivores standard pelleted ration, went off feed when the during winter, however, much of this is in the form concentration of volatile oils in the rumen of fiber and lignin. They are also usually inferior reached a level of approximately 15 microlitres to shrubs in gross energy as determined by a bomb per 10 ml of rumen fluid. This concentration calorimeter. Some shrubs, however, may give erron- corresponds to the concentration of increased eously high caloric values because of high volatile antimicrobial activity observed in in vitro oil content. studies (Figure 2).

Relation of Volatile Oils to Further investigations on volatile oils were Mule Deer Management conducted at Colorado State University (Nagy, 1973) using three species of juniper; J. deppeana A wide variety of evergreen plant species are (alligator juniper), J. osteosperma (Utah juniper), found in the western part of the North American and J. scopulorum (Rocky Mountain juniper). The continent. Many of these plants contain a class of volatile oil content of these species varied chemical substances commonly referred to as volatile somewhat according to site, but on the average, oils. In chemistry the term "volatile oil" means a J. scopulorum contained the highest concentration, wide variety of compounds which can be extracted followed by J. osteosperma and J. deppeana. from plants and plant parts by steam distillation. These "oils", although not soluble in water, but To examine deer preferences cafeteria type of soluble in ether, alcohol, and other organic sol- feeding trials, using fresh branches of the three vents, are not true oils, but various terpene juniper species every two days, were conducted for derivatives. Plant physiologists consider them as two weeks on 6 mule deer. Four animals were placed metabolic waste products, while ecologists recognize in individual pens and two (ccntrol) were placed

75 Mule Deer Nutrition and Plant Vtilization 10'9 o INOCCULUM .R. TRIOENTRTR VS. E. COLI .- MERN Of fl. TRIO. VS. E. COLI 10' R. NOVR VS. E. COLI -- MERN OF fl. NOVA VS. E. COLI

1o7

1or

10%

10'

'0 2 4 6 0 10 12 1't 16 18 20

Figure 1. Antibacterial action of the essential oils of A. tridentata and A. nova against E. cs.

lo=I --4 CRPTIVEOFER DEER

Figure 2. Antibacterial action of the essential oils of A. tridentata against the rumen microorganisms of wild and captive deer.

Mule Deer Nutrition md PZmt UtiZization in a pen together. During the trial, the animals Conclusions received 45 percent of their previous average daily food intake of a concentrate ration. Alligator There is an indication that in many deer juniper was much preferred over the other two spe- ranges of the west, deciduous shrub species are cies. The average total consumption per sample decreasing in numbers with the simultaneous in- (two days) per deer was 896 grams for Alligator, 113 creasing of some volatile oil containing species grams for Rocky Mountain, and 84 grams for Utah such as sagebrush and juniper. Land management juniper. The average volatile oil content of Alli- agencies are at the same time faced in many areas gator juniper was 0.6 percent (dry weight basis), with large-scale alteration of traditional deer that of Rocky Mountain and Utah juniper was 3.5 per- winter ranges, due to proposed energy development cent and 0.9 percent respectively. It seemed, there- and other activities. The task to determine which fore, that deer selected against the high volatild species and subspecies of plants should be used oil containing foliage of Rocky Mountain juniper during revegetation of depleted deer winter ranges but did nor explain why Alligator juniper was will fall on the land use manager. His knowledge preferred over Utah juniper. in practical and theoretical deer nutrition will be of prime importance during the accomplishment For this reason, we wanted to examine the of these tasks. possibility that deer are able to differentiate between different volatile oil levels in a pelleted The solution to reestablishing nutritious ration. Volatile oils of Rocky Mountain juniper shrubs containing low levels of volatile oils may were mixed in standard pelleted ration in different be the recreation of those environmental condi- concentrations (0, 1, 3, and 5 percent volatile oil tions which originally permitted their establish- levels). Deer were fed this ration in three cafe- ment and subsequent proliferation. Thus, the teria type trials. Results showed a strong prefer- judicious use of site disturbance mechanisms ence by deer for rations that contained the lowest coupled with favorable climatic conditions and concentration of volatile oils in each trial. animal and human management may be the best hope for saving our prime mule deer ranges. Gas chromograms revealed the presence of approximately 20 to 25 different volatile oils in each of the three investigated juniper species. Literature Cited The amount of each individual compound seems to be a characteristic of the juniper species. These volatile oils can be divided into three main groups: Annison, E. F. and D. Lewis. 1959. Metabolism in monoterpene hydrocarbons, oxygenated monoterpenes, the rumen. Methuen and Co. Ltd., London: and sesquiterpenes. Longhurst & (1968) suggest- John Wiley and Sons, Inc., New York. 184 p. ed that palatability of new growth of Douglas fir may depend on the concentration of oxygenated Carhart, A. H. 1944. What deer eat. monoterpenes in the foliage. Our earlier individual American Forests 50:383-385. trials with rumen microorganisms suggested that oxygenated monoterpenes usually exercised the Church, D. C. 1969. Digestive physiology and strongest antimicrobial action. To test the hy- nutrition of ruminants. Vol. 1. 316 p. pothesis that deer, besides total levels of volatile oils in the foliage, would also select Cook, C. W. 1972. Comparative nutritive according to these groups (or group constituents) values of forbs, grasses and shrubs. p. pelleted rations containing 1 percent monoterpene 303-310. In wildland shrubs -- their biology hydrocarbons, oxygenated monoterpenes and sesqui- and utilization. USDA Forest Service General terpenes were fed to deer. Results indicated Tech. Rep. INT-1, 494 p. Intermt. Forest that deer select away from high oxygenated mono- and Range Exp. Stn., Ogden, Utah. terpene concentrations preferring foliagewhich contains more monoterpene hydrocargons or sesqui- Dietz, D. R. 1970. Definitions and compo- terpenes. We feel that this selective ability by nents of forage quality. p. 1-9, In Range deer was the reason why Utah juniper with relatively and Wildlife habitat evaluation -- a research low volatile oil content was low on preference symp., USDA Forest Serv. Misc. Pub. 1147. during the feeding trials with juniper branches. Utah juniper showed a much higher oxygenated . 1972. Nutritive value of shrubs. p. monoterpene content than either Rocky Mountain or 289-302. In wildland shrubs -- their biology Alligator juniper. and utilization. USDA Forest Service Gen. Tech. Rep. INT-1, 494 p. Intermt. Forest The foregoing discussion illustrated that in and Range Exp. Stn., Ogden, Utah. general volatile oils exercise antimicrobial action on rumen microorganisms. These microorganisms, , Robert H. Udall, and Lee E. Yeager. 1962. however, are able to withstand certain low concen- Chemical composition and digestibility by trations of the oils without adverse effects. More- mule deer of selected forage species, Cache La over, it seems that deer during their evolutionary Poudre Range, Colorado. Colorado Game and time period learned to recognize these harmful Fish Dept., Tech. Bull. 14:89 p. effects and are able to select only for the lowest volatile oil containing forage, but also for the French. C. E., L. C. McEwen, N. D. Magruder, and forage that contains fractions of oils with the others. 1955. Nutritional requirements of least antimicrobial action. white-tailed deer for growth and antler development. Pa. Agr. Exp. Stn. Bull. 600. 50 p.

77 hLe Deer Nutrition and Plant Utilization Julander, 0. 1962. Range management in rela- deer nutrition in Arizona chaparral and tion to mule deer habitat and herd productivity desert habitats. Arizona Game and Fish Dep., in Utah. J. Range flanage. 15:278-281. Res. Div., and USDA For. Serv., ~ockyMt. For. and Range Exp. Stn. Spec. Rep. 3, 39-52. Kufeld, R. C., 0. C. Wallmo, and C. Feddema. 1973. Foods of the Rocky Mountain mule deer. USDA Forest Service Res. Pap. RM-111, 31 p. Rocky Mountain Forest and Range Exp. Stn., Ft. Collins, Colorado

Longhurst, W. M., H. K. Oh, M. B. Jones, and R. E. Kepner. 1968. A basis for palatability of deer forage. Trans. N. Amer. Wildl. Conf. 33:181-189.

Nagy, J. G., H. W. Steinhoff, and G. M. Ward. 1964. Effects of essential oils of sagebrush on deer rumen microbial function. J. Wildl. Mgmt. 28:785-796.

and R. P. Tengerdy. 1967. Antibacterial action of the volatile oils of Artemisia tridentata and Artemisia nova on aerobic bacteria. Appl. ~icrobior15:819-821. --. 1968. Antibacterial action of the volatile oils of Artemisia tridentata (big sagebrush) on bacteria from the rumen of mule deer. Appl. microbial. 16:441-444.

Nichol, A. A. 1938. Experimental feeding of deer. Univ. Arizona. Agr. Exp. Stn. Tech. Bull. 75. 39 p.

Oh, H. K., T. Sakai, M. B. Jones, and W. M. Longhurst. 1967. Effects of various essential oils isolated from Douglas fir needles upon sheep and deer rumen microbial activity. Appl. Microbiol. 5:777-784.

Peterle, T. J. 1975. Deer sociobiology. Wildl. Soc. Bull. 3:82-83.

Roughton, R. D. 1972. Shrub age structures on a mule deer winter range in Colorado. Ecol. 53:615-625.

Schneeweis, 3. C., K. E. Severson, and L. E. Petersen. 1972. Food habits of deer in the Black Hills: Part I. Northern Black Hills. South Dakota State Univ. Agr. Exp. Stn. Bull. 606. 35 p.

Shepherd, H. R. 1971. Effects of clipping on key browse species in Southwestern Colorado. Colorado Div. Game, Fish and Parks Tech. Pub. 28. 104 p.

Short, H. L. 1966. Effects of cellulose levels on the apparent digestibility of feeds eaten by mule deer. J. Wildl. Manage. 30:163-167.

. 1969. Physiology and nutrition of deer in southern upland forests. p. 14-18. In: white- tailed deer in the southern forest haGtat. L. K. Halls (ed.) Symp. Proc. Nacogdoches, Texas, USDA Forest Serv., Southern Forest Exp. Stn. 130 p.

Urness, P. J. 19731 Chemical analyses and In Vitro digestibility of seasonal deer forages.Iny

Mule Deer Nutrition and Plant Utilization MULE DEER PRODUCTIVITY--PAST AND PRESENT

Phillip J. Zwank Ph.D. Candidate Utah Cooperative Wildlife Research Unit Utah State University Logan, Utah 84322

Abstract

Productivity data demonstrate that the potential for rapid increase exists in mule deer populations. Fawns are capable of breeding; yearlings generally have single fawns; adult and old does usually produce twins, with recorded instances of triplets and quadruplets. Net productivity is significantly less than potential productivity. Ovulation rates are strongly affected by the quality of nutrition prior to the rut. It appears there are always sufficient bucks for breeding purposes. Approximately 10 percent losses occur between fertilization and parturition. The greatest loss in net productivity appears to occur during the post-natal period. During the first 45 days after birth, 50 percent of the fawn crop may die. Nutritional deficiencies, predation, diseases, parasitism, weather, and accidents may cause post-natal mortality. Nutritional deficiencies appear to be the primary factor responsible for post-natal mortality and winter fawn losses. In certain areas, predation, especially by coyotes, accounts for a large percentage of fawn losses. The incidence and effects of diseases on productivity are little known.

A population is a dynamic entity, the numbers of Mule deer inherently possess a high reproduc- which fluctuate as a result of changes in productivi- tive potential. While mule deer usually breed ty, mortality, immigration and emigration. While first as yearlings (Robinette et al. 1955; Asdell migration must be considered (Quick 1962), producti- 1964), they occasionally breed as fawns. After vity is the primary factor responsible for population examining 274 reproductive tracts, Robinette et gains. al. (1955) found evidence that 7 does (2.6 percent) had conceived as fawns. Brown (19601, however, Murie (1951) noted that the rate of increase in found that 4 of 19 females (21 percent) in the a population is of vital interest to the game manager, Guadalupe Mountains of New Mexico became pregnant but is the most difficult factor to determine. This when less than 1 year of age. Papez (1976) de- is especially true for mule deer (Odocoileus he- termined that 3 of 12 does (25 percent) had ovu- mionus), whose productivity varies with both age and lated first as fawns in the Ruby Butte Mountains geographical area and whose secretive nature hinders in Nevada, and 1 had given birth. While these accurate determination of reproductive success. For examples show that female fawns are capable of being these reasons, extreme care must be taken when com- bred, their reproductive capacity is believed to be paring productivity of mule deer populations or insignificant in the breeding potential of most when generalizing about mule deer productivity. herds (Hickman 1971).

Both potential and net productivity should be Yearlings generally bear single fawns, although recognized. Robinette (1956) stated that potential twins may be produced (Yoakum 1966). Prime adult productivity is the theoretical rate at which a does (between 3 and 7 years of age) usually produce species can increase if no mortality occurs, and net twins, occasionally triplets (Robinette et al. 1955), productivity or net increase is the actual yearly and instances of quadruplets have been recorded rate of increase after mortality from all causes have (Sears and Browman 1955; Trodd 1962). been deducted. Only rarely does the net productivity of a herd in the wild ever closely approach the The reproductive potential appears to drop only potential productivity (Robinette 1956). slightly for old (7+ year-old) does (Hickman 1971). I recaptured and laparotomized one doe this past Reproductive Potential winter which had been tagged as a fawn in 1964. She was pregnant with twin fetuses. A second doe, deter- The maximum rate of increase in a population de- mined to be more than 12 years old by cementum pends upon the genetically controlled reproductive annulation aging, also was carrying twins. potential (Andrewartha and Birch 1954), which for a mule deer population is determined by the number of Table 1 illustrates the theoretical reproduc- does in the population capable of reproducing, and tive potential for mule deer. Note that the original the fecundity of each. doe may have 104 direct descendants within a 6-year

79 Mule Deer Productivity--Past and Present period. In addition, penned deer studies indicate occur, and enters the uterus. If the ovum is fer- that highly productive does produce more female than tilized, the corpus leteum persists as a corpus male fawns (Verme 1969; Robinette et al. 1973). Thus, luteum of pregnancy; if not, degeneration begins in fawn crops from highly productive populations may 14 to 15 days. Unfertilized ova are expelled, while be weighted toward females. fertilized ova develop into embryos, implant in the uterus, and begin fetal development. During gesta- Two captive herds of white-tailed deer tion, the corpus luteum of pregnancy plays a vital (Odocoileus virgianus) have approached their theoreti- role in suppression of subsequent follicular develop- cal reproductive potential. The George Reserve herd ment and maintenance of pregnancy. After approxi- in Michigan (Table 2), which was started with 4 adult mately a 200-day gestation period, the fawn is horn. does and 2 bucks in March 1938, increased to 160 deer by December 1943. Investigators also found two dead Ovulation Rates deer on the Reserve during this 6-year period (Chase and Jenkins 1962). As fawns were not thought to Ovulation rates may be estimated through micro- breed, the reproductive potential of this herd was scopic ovarian analyses. Accurate sampling is 188, which is very close to the 162 deer observed. difficult, because non-fertilized corpora degenerate On the Seneca Army Depot in New York, a herd of 30 rapidly and accessory corpora lutea and other luten- white-tailed deer in 1948 grew to 1,121 in 1953 izing structures, which may be found in the ovary, (Hesselton et al. 1965). must be differentiated (Gill 1972).

The explosive character of mule deer populations Ovulation rates appear to be affected strongly is demonstrated on the Kaibab Plateau in Arizona and by the quality of nutrition just prior to and during in Cache National Forest in northern Utah. On the the rut (~onghurstet al. 1952). Past and present Kaibab Plateau the deer population was estimated to range comparison studies in California (Taber and be 4,000. in 1906 (Russo 1964). By 1924, the popu- Dasmann 1958; Salwasser 1975) and Utah (Julander lation was estimated to be between 30,000 and 100,000 1961; Pederson 1970) have demonstrated that does on (Caughley 1970). Doman and Rasmussen (1944) esti- good summer and fall ranges have higher ovulation mated the Cache population at 250 in 1917 and 6,000 rates (Table 4). in 1939. While these examples of exponential rates of increase were under unusual conditions, given Gill (1972) found that ovulation rates were favorable habitat, deer usually produce a net annual highly correlated with snow depths in Colorado. population increase of between 20 and 30 percent During the winter, the nutritional quality of the (Longhurst et al. 1952; Robinette 1956; Chase and forage is lowest and snow limits range accessibility Jenkins 1962; Nellis 1968; Hickman 1971). (Gilbert et al. 1970). Heavy snows in October of 1970 and 1971 concentrated deer in poor condition on Net Productivity the winter ranges early in the season. The ovulation rate during a mild winter was significantly higher The number of fawns recruited into the breeding (P<.10) than during the severe winters (Table 5). population determines net productivity (Salwasser 1975). Mule deer productivity generally is estimated Yoakum (1966) noted that some does may not by game managers from observed pre-hunting and post- breed when range conditions are inadequate, but hunting season doe:fawn ratios, which may be biased. seldom, If ever, are there insufficient bucks for If the previous year's net productivity was high, a breeding purposes. Even with a sex ratio of from large proportion of less productive yearlings are 10 to 12 does for each buck, successful breeding included in the population and the doe:fawn ratio. occurs (Yoakum 1966). In Utah, declining recruit- This would tend to depress the apparent size of the ment does not appear to be due to insufficient bucks, present year's fawn crop (Nellis 1968). Post-season since 1 found all 58 does, 1%years of age and older, ratios may add an additional bias, if differential trapped during this past winter were pregnant. mortality favored a certain age-class, either during the harvest or in the "winter kill" (Hickman 1971). Intra-uterine Mortality While the validity of either method may be questioned, doe:fawn ratios are used extensively to monitor Reproductive losses that occur between fertili- population trends. zation and parturition appear to be minimal in mule deer. Robinette et al. (1955) observed an ova loss Productivity trends show that recruitment is of 7.5 percent (789 embryos or fetuses from 853 declining throughout the West (Table 3). Significant corpora lutea) during the first month following con- losses appear to be occurring either during pregnancy, ception and a 10.5 percent loss at midpoint of preg- the immediate post-natal period, or during the first nancy. Recent studies by both Nellis (1968) in few months after birth. Montana and Papez (1975) in Nevada found a similar 10 percent decrease between corpora lutea and fetal Prior to discussing the extent of these losses rates (25 fetuses from 26 corpora lutea in Montana; and the possible causes, perhaps we should review 69 fetuses from 71 corpora lutea in Nevada). briefly the reproductive cycle in deer. Ovarian analysis, first discussed by Cheatum (1949) for Salwasser (1975) found only 1 resorbing fetus white-tailed deer, has recently been outlined by and no other signs of abnormality in a necropsy Papez (1976) for mule deer. During the fall, sample consisting of 142 all age-class does. Nellis numerous follicles appear on the ovaries, one to four (1968) observed an intra-uterine mortality rate of will mature and ovulate. The ripe follicle ruptures 2 percent or 4 atrophic fetuses from 226 recovered spontaneously, releasing the ovum into the oviduct. fetuses. Again, this is very similar to the 1.7 At this time, the ruptured follicle develops into a percent mortality (21 of 1,263), based upon visible hormone secreting gland--the corpus luteum. The ovum remains of dead fetuses, observed by Robinette et passes through the oviduct, where fertilization may al. (1955).

Mule Deer Productivity--Past and Present 80 Early Post-Natal Mortality be: mountain lions (Felis concolor), coyotes (Canis latrans), and bobcats (Lynx rufus). The greatest loss in net productivity appears to occur during the post-natal period. Of 224 births Trainer (1975) determined that coyotes recorded under penned conditions, 17 fawns (7.6 per- accounted for 55 percent of the summer radio- cent) died during the first 48 hours (Robinette et al. monitored fawn losses. Salwasser (1975), on the 1973). Trainer (1975), in Oregon, found only 6 of other hand, felt that it was unlikely that coyotes 189 fawns (3 percent) examined in the field imme- were totally responsible for summer fawn losses. diately post-partum to be dead or emaciated and not He further stated that the occurrence of fawn re- likely to survive. While Trainer's (1975) data mains in coyote scats probably represented scav- showed few fawns to die immediately post-partum, both enging to a large degree. Salwasser (1974) and Trainer (1975) observed losses approximating 50 percent of the fawn crop during the Diseases and Parasites first 45 days after birth. Habitat deficiencies, predation, diseases, parasitism, weather, and accidents Little information is available concerning the may cause post-natal fawn mortality. quantative effects of parasites and diseases on young deer. The incidence of parasitism and Nutrition diseases generally are linked closely to the nutritional level of the host. Cowan (1956) and The recurring theme through past and present Yoakum (1966) claimed that, given a satisfactory literature is that nutrition is the prime factor food supply, deer appear to resist the various affecting productivity (Leopold et al. 1951; diseases and parasites to which they are susceptible. Longhurst et al. 1952; Robinette et al. 1955; Robinette 1956; Julander 1961; Pederson 1970; In penned studies, Robinette et al. (1973), Salwasser 1975). Does on inadequate winter diets observed cases of necrotic stomatitis or necro- show large weight losses, which impair development of bacillosis caused by Sperophoures necrophores. the fetus, resulting in fawn mortality at birth or I also observed necrotic stomatitis in Utah mule shortly thereafter (Verme 1969). Fawns born to does deer fawns reared in ,>ens. in poor condition are in poor condition, stillborn, small, weak, unable to nurse or the mother does not Parasitic blood worms (Elaeophora schneideri) produce enough milk to rear multiple fawns (Yoakum may be responsible for neonatal fawn losses in New 1966). While insufficient protein usually is con- Mexico (Snyder 1968). In Arizona, a bacteria sidered as the first deficient nutrient, diets lacking (Pseudomonas aeruginose), which would be fatal to in phosphorus also have been shown to reduce produc- newborn fawns, was found in the udder of a doe tivity (Swank 1956). (LeCount 1972). Oregon, Arizona, Utah, and New Mexico currently are investigating the incidence -Cover of diseases and parasites in mule deer and their influence on productivity. Fawning cover has been implicated as an important factor in summer fawn survival. Salwasser (1975) Weather found when comparing fawn survival on two areas, while one supported a higher density of coyotes than the Weather affects net productivity by its direct other, it also yielded nearly twice the percentage effect upon forage production (Teer et al. 1965). of summer fawn survival. He related the better fawn Also, inclement weather during the fawning period survival to superior fawning cover. may cause considerable losses. In 1975, 12 dead fawns were found in the Uinta Mountains of northern Water Utah after a 10-inch snowfall during the fawning period (personal conversation dated 18 April, 1976, In drier areas', lack of available free water and with D. Winn, Dept. of Wildlife Science, Utah State low nutritional intake exist during periods of drought. University, Logan, Utah 84322). Plants become dormant and protein levels drop below the optimum for deer growth (Swank 1958). Deer con- Accidents centrate in the vicinity of permanent water and com- Pete for the low quality forage. Longhurst et al. A few fawns may die from accidents, such as (1952). Swank (1958), and Yoakum (1966) thought that falls and drownings (Robinette 1956). During the a lack of free water and low nutritional intake may neonatal period, some fawns are killed on farms by reduce recruitment. Urness et al. (1971), however, mowing machines, because they attempt to hide rather determined that reduced recruitment in Arizona was than flee (Haugen and Specke 1958). Also, fawns due to high fawn mortality, and nutritional deficien- have difficulty crossing fences and often become cies probably were not responsible. entangled in them and die (Franzen 1968).

Predation Nutrition

Early authors reported that predation was in- Winter die-offs from malnutrition usually influential in mule deer population dynamics and that volve differential mortality between age-classes, coyotes were responsible for many fawn losses (Murie because certain age groups are less able to com- 1935; Horn 1941; Cahalane 1947). Robinette and Olsen pete. Fawns, because of their smaller size, cannot (1944), in Utah, reported 49 percent (22 of 45) of a move well in deep snow, nor reach as high as adults fawn crop was taken by a coyote in a 500-acre en- to browse on shrubs for forage (Huddleston 1964). closure. Richens (1961), however, recorded Utah mule In 1936, Doman and Rasmussed (1944) observed that deer predators (in descending order of importance) to of 114 "winter-killed" deer in northern Utah. 80

81 Mule Deer Productivity--Past and Present percent were fawns. Robinette et al. (1957) de- Janson, Montana Dept. Fish and Game, Missoula, termined that fawn losses are usually from two to Montana 59801). three times that of older deer. Huddleston (1964), however, observed 58 percent (21 of 54) of the winter Summary mortality in the Cache Valley of northern Utah was comprised of fawns. Productivity data demonstrate that the potential for rapid increases in mule deer populations Predation still exists. Net productivity estimates, derived from doe:fawn ratios, show that significant losses Predation, primarily by coyotes, accounted for may be occurring during pregnancy, the immediate 79 percent (15 of 19 deaths) of radio-tracked winter post-natal period, or during the first few months fawn losses in Oregon (Trainer 1975). In Utah, 28 of of the fawn's life. Nutrition appears to be the 31 dead deer found during the winter of 1975 were primary limiting factor responsible for reduced determined to be coyote kills and, of the 28 all ovulation rates, post-natal mortality and winter but 3 were fawns (Nielson 1975). In Montana, a fawn losses. In certain areas, predation, especial- doe:fawn ratio of 100:40 at the end of the 1975 ly by coyotes, accounts for a large percentage of hunting season dropped to 100:lO in February. This fawn losses. The incidence and effects of diseases occurred during a relatively mild winter, therefore, on productivity are, as yet, little known, but on- coyote predation was thought to be a major cause of going studies may help to determine how these mortality (letter dated 10 March, 1976 from R. G. limiting factors influence mule deer populations.

Table 1. Reproductive potential of mule deer over a 6-year period.

Adult Yearling Fawns Total Annual population population percent increase

Introduction 1(2) 0 2(1M, IF) 3 33

Year 1 1(2) 1(1) 3(1M, 2F) 5 60

Year 2 2(2) 2(1) 6(3M, 3F) 10

Year 3 4(2) 3(1) 11(5M, 6F) 18

Year 4 7(2) 6(1) 20(10M, 10F) 33 55

Year 5 -13 (2) -lO(1) -36(18M, 18F) -5 9 56 Winter count 23 18 64 105

( ) Fawns produced

Table 2. Reproductive potential of George Reserve white-tailed deer.

Year Adult Yearling Fawns Total Annual population population percent increase

1939 4(2) 0 8(4M, 4F) 12 50

1943 32(2) - -20(0) -64(32M, 32F) -116 62 Winter count 52 32 104 188

( ) Fawns produced

Mule Deer Productivity--Past and Present 82 Table 3. Mule deer productivity trends as reported by state representatives at the Fifth Western States Mule Deer Workshop, 1974.

State Comments

Arizona "Production came up a year ago, but has probably dropped back down. .. The statewide low has been 25 fawns/100 does and the high has been 65 fawns1100 does."

California "Twenty years ago production was about 65 fawns1100 does, but now has declined to 35 fawns/ 100 does."

Colorado "There are no fawn production figures on a statewide basis, but on one area there were 31 fawns per 100 does in 1974 compared to 1965 when there were 60-70 fawns per 100 does."

Idaho "Fawn production is up over the last year by about 5 fawns per 100 does for a state average of 75 fawns per 100 does."

Montana "Production in the western part of the state is relatively low and still declining... In 1973 they had 40 fawns per 100 does; in 1974 so far there has been 37 fawns per 100 does."

Nevada "Population trends are down prior to this year, but there are no fawn production figures."

New Mexico "Population trends are down slightly. Fawn production varied from a low of 12 fawns Per 100 does to a statewide trend of 35-45 fawns per 100 does."

Oregon "Mule deer are still declining and have been doing so since 1968-1969 winter. A statewide average of 54 fawns per 100 does remained in December 1974."

Texas "Fawn ratios are 19 fawns per 100 does."

Utah* "The severe winter of 1972-1973 resulted in fawn losses and a decrease in the following summer's fawn crop due to the poor physical condition of does."

Washington "The pre-season classification shows 65 fawns per 100 does. This is down from about 80 fawns per 100 does of a year ago."

Wyoming "Reproduction looks good and is increasing."

"(Personal conversation dated 5 March, 1975, with Rodney John, Division of Wildlife Resources, Salt Lake City, Utah 84101).

83 Mule Deer Productivity--Past and Present Table 4. Past and present comparison of productivity from does 1%years and older on good and poor ranges.

Copora Percent Fetus (es) Area Years lutealdoe pregnant per doe Fawn:doe ratio Source

Shrubland, CA 1951-1953 1,60(18) 94(18) 1.45(18) 811100 post-season Taber and haparral, CA 1949-1950 0.82(11) 97(11) 0.71(11) 721100 post-season Dasmann (1958)

Devil's Garden, CA 1975 1.87(67) 99(67) 1.73(67) 20-501100 pre-season Salwasser Crooked Creek, CA 1975 1.62(48) 90(48) 1.56(48) 45-751100 pre-season (1974)

Sublette, ID 1954-1956 1.95(41) 100(9)* 1.85(33) 1221100 post-season Julander et Antimony, UT 1954-1956 1.31(114) 63(8)* 1.19(27) 511100 pre-season al. (1961)

LaSal Mountains, UT 1967-1969 ------1.01(305) 931100 pre-season Pederson Henry Mountains, UT 1967-1969 ------.59(299) 591100 pre-season (1970)

( ) Sample size * Yearlings only

Table 5. Comparison of productivity from does 1%years and older for mild (1969) and severe (1970, 1971) winters in Colorado.

Corpora Percent Fetuses Years lutealdoe pregnant per doe Fawn:doe ratio Source

Middle Fork 1969 2.02(41) 100 1.93 931100 pre-season Gill (1972)

1970 1.76(42) 88 1.64 721100 pre-season

1971 1.73(52) 9 8 1.61 731100 pre-season

( ) Sample size

MuZe Deer Productivity--Past and Present LITERATURE CITED Huddleston, R. J. 1964. Malnutrition and other losses on the Cache deer herd winter 1963-1964. Utah Coop. Wildl. Res. Unit. Sp. Rep. 10. 12 pp. Andrewartha, H. G., and L. C. Birch. 1954. The distribution and abundance of animals. Univ. of Julander, O., W. L. Robinette, and D. A. Jones. 1961. Chicago Press. Chicago. 782 pp. Relation of summer range condition to mule deer herd productivity. J. Wildl. Manage. 25(1): Asdell, S. A. 1964. Patterns of mammalian reproduc- 54-60. tion. Cornell Univ. Press. Ithaca. 670 pp. LeCount, A. 1972. Arizona's fawn mortality study. Brown, G. 1960. Deer productivity studies. Nevada Annu. Mule Deer Workshop. 2:8-11. Dept. Fish and Game. P-R Proj. Rep., W-75-R-7. 14 PP. Leopold, A. S., T. Riney, R. McCain, and L. Tevis, Jr. 1951. The Jawbone deer herd. California Cahalane, V. H. 1947. A deer-coyote episode. J. Dept. Fish and Game Bull. 4. 139 pp. Mammal. 28(1):36-39. Longhurst, W. M., A. S. Leopold, and R. F. Dasmann. Caughley, G. 1970. Eruption of ungulate populations, 1952. A survey of California deer herds, their with emphasis on Himalayan thar in New Zealand. ranges and management problems. California Ecology 51(1):53-72. Dept. Fish and Game Bull. 6. 52 pp.

Chase, W. W., and D. H. Jenkins. 1962. Productivity Murie, J. 1951. The elk of North America. Stack- of the George Reserve deer herd. Proc. White- pole Co., Harrisburg, Pennsylvania. 376 pp. tailed Deer Dis. Symp. Univ. of Georgia. 1: 78-87. Murie, 0. J. 1935. Food habits of the coyote in Jackson Hole, Wyoming. U.S. Dept. Agric. Circ. Cheatum, E. L. 1949. The use of corpora lutea for 362. 24 pp. determining ovulation incidence and variations in the fetility of white-tailed deer. Cornell Vet. Nellis, C. H. 1968. Productivity of mule deer on 39 (3) :282-291. the National Bison Range, Montana. J. Wildl. Manage. 32(2):344-349. Cowan, I. M. 1956. Life and times of the coast black- tailed deer. Pages 523-619. In W. P. Taylor Nielson, D. B. 1975. Coyotes and deer. Utah Sci. ed. The deer of North ~merica. The Stackpole Agric. Exp. Sta. 36(3):87-90. Co., Harrisburg and the Wildl. Manage. Inst., Washington, D.C. 668 pp. Papez, J. 1976. The Ruby Butte deer herd. Nevada Dept. Fish and Game. P-R Proj. Rep., W-48-K-6, Doman, E. V., and D. I. Rasmussen. 1944. Supple- Bull. 5. IN PRESS. mental winter feeding of mule deer in northern Utah. J. Wildl. Manage. 8(4):317-338. Pederson, J. C. 1970. Productivity of mule deer on the LaSal and Henry Mountains of Utah. Utah Franzen, R. W. 1968. The abundance, migration and Div. Wildl. Res. Publ. 70-2. 133 pp. management of mule deer in Dinosaur National Monument. M.S. Thesis. Utah State Univ. Quick, H. F. 1962. Population dynamics of white- 128 pp. tailed deer. Proc. White-tailed Deer Dis. Symp. Univ. of Georgia. 1:65-77. Gilbert, P. F., 0. C. Walmo, and R. B. Gill. 1970. Effect of snow depth on mule deer in Middle Park, Richens, V. B. 1961. An ecological and management Colorado. J. Wildl. Manage. 34(1):15-23. study of the Daggett deer herd of northeastern Utah. M.S. Thesis. Utah State Univ. 193 pp. Gill, R. B. 1972. Productivity studies of mule deer in Middle Park, Colorado. Annu. Mule Deer Work- Robinette, W. L. 1956. Productivity--The annual shop. 2:40-48. crop of mule deer. Pages 415-429. W. P. Taylor ed. The deer of North America. The Haugen, A. O., and D. W. Speake. 1958. Determining Stackpole Co., Harrisburg and the Wildl. Manage. age of young fawn white-tailed deer. J. Wildl. Inst., Washington, D.C. 668 pp. Manage. 22(3):319-321. , C. H. Baer, R. E. Pillmore, and Hesselton, W. T., C. W. Severinghaus, and J. E. Tanck. C. E. Knittle. 1973. Effects of nutritional 1965. Population dynamics of deer at the Seneca change on captive mule deer. J. Wildl. Manage. Army Depot. New York Fish and Game J. 12(1): 37(3) :312-326. 17-30. , J. S. Gashwiler, D. A. Jones, and Hickman, G. L. 1971. The Coalville deer herd in H. S. Crane. 1955. Fertility of mule deer in northeastern Utah: Its ecology and management. Utah. J. Wildl. Manage. 19(1):115-136. M.S. Thesis, Utah State Univ. 105 pp. , J. B. Low, and Horn, E. E. 1941. Some coyote-wildlife relation- D. A. Jones. 1957. Differential mortality by ships. Trans. N. Am. Wildl. Conf. 6:283-286. sex and age among mule deer. J. Wildl. Manage. 21(1) :I-16.

85 Mule Dcer Productivity--Past and Present , and 0. A. Olsen. 1944. Studies of the productivity of mule deer in central Utah. Trans. N. Am. Wildl. Conf. 9:156-161.

Russo, J. P. 1964. The Kaibab north deer herd-- Its history, >roblems, and management. Arizona Game and Fish Dept. P-R Proj. Rep., W-63-R. 195 pp.

Salwasser, H. J. 1974. North Kings deer herd fawn production and survival study. California Dept. Fish and Game. P-R Proj. Rep., W-51-R. 78 pp.

. 1975. Interstate wildlife study: Spring 1975 collection--Interim Report. Univ. of California, Berkeley. 47 pp.

Sears, H. S., and L. G. Browman. 1955. Quadruplets in the mule deer. Anat. Rec. 122(3):335-340.

Snyder, W. A. 1968. Major factors influencing mule deer popuations and harvest trends in New Mexico. Ann. Conf. Western State Game and Fish Commis- sioners. 48:237-240.

Swank, W. G. 1956. Protein and phosphorus content of browse plants. Trans. N. Am. Wildl. Nat. Res. Conf. 21:148.

Swank, W. G. 1956. The mule deer in Arizona Chaparral and an analysis of other important deer herds. Arizona Game and Fish Dept. Wildl. Bull. 3. 109 pp.

Taber, R. D., and R. F. Dasmann. 1958. The black- tailed deer of the Chaparral. California Dept. Fish and Game Bull. 8. 163 pp.

Teer, 3. G., J. W. Thomas, and E. A. Walker. 1965. Ecology and management of white-tailed deer in the Llano Basin of Texas. Wildl. Monogr. 15. 62 PP.

Trainer, C. 1975. Direct causes of mortality in mule deer fawns during summer and winter periods on Steen's Mountain, Oregon--A progress report. Annu. Conf. Western State Game and Fish Commis- sioners. 55:163-170.

Trodd, L. L. 1962. Quadruplet fetuses in a white- tailed deer from Esponola, Ontario. J. Mammal. 43(3) :414.

Urness, P. J., W. Green, and R. K. Watkins. 1971. Nutrient intake of deer in Arizona Chaparral and desert habitats. J. Wildl. Manage. 35(3): 459-475.

Verne, L. J. 1969. Reproductive patterns of white- tailed deer related to nutritional plane. J. Wildl. Manage. 33(4):881-887.

Yoakum, J. 1966. Life and death of deer herds. Univ. California Agric. Ext. Serv. Deer Seminars. p. 11-19.

Mule Deer Productivity--Past and Present REGULATIONS AND THE MULE DEER HARVEST- POLITICAL AND BIOLOGICAL MANAGEMENT

Richard N. Denney Big Game Supervisor

Colorado Division of Wildlife Denver, Colorado

Abstract

The mule deer population in Colorado, and in the west generally, began increasing during the 1920's from a low at the beginning of the century to an accelerated high in the late forties to the early sixties, then began a rapid decline to the present. Harvests followed this same pattern. The applicable season regulations resulting in these harvests stem from biological considerations (various population and forage parameters) and political influences (true politics, as well as soci- ologic and economic factors). The application of computerized systems analysis in the form of herd simulation models is advanced as a means of measuring the impact of variable man-controlled management practices. This can not only identify areas of concern, but also point out types, amounts and qualities of data needed, without impacting the actual resource with trial and error methods.

INTRODUCTION

During the mid-1850's the pioneers arriving in western states was affected through many different the territory of what is now Colorado found vast types of regulations and administrative philoso- numbers of deer, elk, bighorn sheep and bear in the phies. Regardless of the management approach, mountains west of Denver. Though most of these whether it was ultra-conservative or super- pioneers were initially in search of gold, many com- exploitive, the mule deer trend has followed es- munities were established, and, because trade and sentially the same pattern throughout the west: a store goods were limited and difficult to obtain, gradual build-up of herds beginning in the 19201s, wild game was the primary source of meat for these with a peaking somewhere in the late forties or people. As the communities became more permanent early fifties to the early sixties, and then a their meat needs were supplied increasingly by pro- general decline during the sixties, and continuing fessional exploiters of the abundant wildlife. to the present. Market hunters began to make such inroads on various big game populations that the citizens became There is an increasing number of advocates of alarmed. Hunter (1959) estimated that 100,000 big the concept that wildlife constitutes an early game animals per year must have been killed to sup- warning system of ecosystem deterioration. In the ply Colorado's population at that time. In 1867 face of current knowledge this can hardly be re- the first game laws were enacted, which prohibited futed. There are many people, particularly the the taking of wildlife during the breeding season. general public, who are quick to lay the mule deer Still, no specific seasons or licenses were in ef- decline on overshooting allowed by liberal regu- fect, but game laws became increasingly restrictive. lations. The fallacy of the antlered only manage- By 1903 the first deer license was authorized at ment concept is illustrated by the fact that states $1.00, but elk, antelope and bighorn sheep seasons (Arizona, California and Oregon) with primarily were still closed, and bison had disappeared by the buck only hunts have critically low buck to doe turn of the century. The early 1900's represented ratios, while states harvesting both sexes (Colorado, the low point in Colorado's big game populations, Idaho, Nevada and Utah) have experienced only half but through sound wildlife management the game herds the harvest decline of the former (Salwasser 1975). were built up to the point that by 1960 they were some of the most important in the nation. Inasmuch as the mule deer decline is general throughout the west, it is obvious that the cause This is similar to the history of big game in must be a composite of many factors, some of which most of the western states. During the 19501s, how- we probably have not identified to date. In view ever, the management of mule deer in the various of the return to population fluctuations of the

87 Requlutations and the Mule Deer harvest past, is it possible that certain cyclic phenomena Biologically-Based Regulations are being exhibited in a species that we never previously considered to be cyclic? I doubt this, but Colorado has attempted to manage its big game in the light of the habitat decrease and degradation populations on the basis of herd units. The on-the- experienced in the west in the past 20 years, we will ground biological data obtained by Division person- never again see the incredible harvests of a century ne 1 included : ago, or the documented kills of the recent past. 1. Population trend counts obtained on winter This paper will attempt to evaluate the various concentration areas by aerial and ground regulations pertaining to mule deer harvest in Colo- observations. rado (probably applicable to the entire west), how they were effected by biological and political con- 2. Pre- and post-season sex and age ratios siderations and how such considerations may affect obtained by aerial and ground observations regulations in future mule deer management. on selected seasonal ranges.

3. Wounding loss assessment based on field COLORADO MULE DEER HARVEST observations.

During the period 1940 through 1975, Colorado 4. Winter mortality based on field work in has yielded a mule deer harvest of 2.7 million ani- winter concentration areas. mals to over 4.7 million hunters for an average success ratio of 57 per cent. This 36-year period 5. Browse production and utilization data covers an era of relatively gradual mule deer popu- derived from measured intensive transects lation increase until a peak was reached in the late and estimated extensive transects on winter fifties and early sixties, at which time an ac- ranges. celerated decline to the present was experienced. The antlered and total harvests, hunter pressure and 6. Deer-days use per acre derived from pellet success ratios are indicated in Figure 1. group counts in association with game range analysis transects.

7. Research data from specific projects on deer range and population dynamics.

Additional biological data which have been considered in formulating season regulations, but derived after-the-fact, are the buck, doe and fawn statistics of the annual harvests, and the percentage of yearlings as determined from dentition determinations at check stations, cementum annuli from incisors obtained at check stations or mailed in by hunters, and antler configuration inspected at check stations or obtained from surveys.

A brief comment on each of the biological factors and their effect in setting season regulations follows:

1. Population Trend Counts. Aerial and ground Figure 1. License sales and deer harvest, 1940- counts of deer are made on established areas or present, Colorado. routes, usually on winter ranges, and under as nearly comparable conditions of time of year, snow- cover and systematics as possible. Inconsistencies During this 36-year period a total of 1,533,121 in weather, affecting snow depth and coverage, bucks, representing an annual average of 42,587, was ambient temperatures and winds, detract from the harvested. Broken down into the three most recent reliability of such counts by introducing variables five-year periods, the annual antlered harvest aver- in flight or count conditions, visibility and deer aged 60,951 during 1961-65, 43,853 during 1966-70, behavior. Population determinations are not possi- and 44,788 during 1971-75. During the 36-year period, ble from such counts, and, at best, they can only 1971 was the only year in which the harvest was serve as an index to the general population trend limited to bucks only. over a relatively long period of time. Hunter success during this period has ranged Another type of trend count has been em- from a low of 26 per cent in 1975 to a high of 88.6 ployed on the Piceance deer herd since 1947, and percent in 1957, but does not represent a function that is a count during one or two days in April of of the deer population alone. The harvest regu- comparable phenological condition each year of the lations affecting these harvests were two deer of deer concentrating on the native hay meadows of either sex in 1957, and antlered only with some Piceance Creek and its tributaries. A track count limited either sex permits in 1975. What were the was made of a portion of this migrating herd, considerations involved in these types of divergent usually during the month of May, for a number of seasons? years until about 1957 when road conditions on

Regulations ad the Mule Deer Harvest Flag Creek forced its termination. However, during effort to bring the herds into what was felt to its life, the track counts were up to two or three be the carrying capacity of the winter range, and times higher than the meadow counts on comparable two, and even three-deer, seasons were held in years. All that can be said of such counts is that large areas of the state until 1969. These seasons they may represent a minimum number present, but were established in the beginning because hunter what per cent of the total herd population in that pressure was limited and we had to utilize the area is unknown. sportsman resource we had available. As hunter receptiveness and pressure increased, certain Trend counts on mule deer have had little political considerations were brought to bear, as direct input in the formulation of season regu- discussed later. lations. 6. Pellet Group Counts. Pellet group counts 2. Sex and Age Ratios. While we talk about were conducted in conjunction with range transects, pre- and post-season sex and age ratios, the emphasis and converted to deer days per acre on the basis of has been on post-season classifications, and these 13 pellet groups per deer per day as determined by are primarily aerial, although some ground counts research investigations at the Little Hills Experi- are conducted in selected areas. These data have ment Station on Piceance Creek. Because of the a greater potential in influencing the establishment many variables and controversy we did not convert of regulations than has been realized in practice. these data to populations, but rather used them as To the best of our knowledge, our buck to doe ratios a deer winter range pressure index relative to past have never been low enough to influence fawn pro- years and other areas, and correlated with browse duction. The number of fawns yields an index to utilization. The other comments under Range Analy- hunting season survival, and, barring unusual winter sis also apply here. mortality, an indication of herd recruitment in the yearling age class the upcoming spring. 7. Research. Deer investigations in important areas have yielded data which have influenced Similarly, we have long used the percentage season regulations to some extent in those areas of yearlings in the harvest as an indicator of herd specifically. It was an early Federal Aid project health. The utilization of sex and age data in herd that stimulated the two-deer season concept in the management regulations will be discussed in more Uncompahgre Plateau, which eventually was applied detail in another section of this paper. almost western-slope wide. Certain types of seasons and mandatory check stations were part of and re- 3. Wounding Loss. Other than superficial sulted from the Middle Park deer study. The results surveys, we have no documentation of the impact of of current deer studies and task forces will un- wounding loss. We have used a rule-of-thumb figure doubtedly be applied to future regulations. of 5-and-10, that is, a wounding loss of five per cent of the harvest in buck only areas, and ten per Political Considerations cent of the harvest in either sex areas. I feel that this is too conservative. Wounding loss re- Political, in the sense used here, is a real ceives little consideration in establishing regu- Pandora's box. It not only includes politics in lations, but may receive attention when more refined the commonly accepted definition, but also in the management is implemented. context of economics and sociology.

4. Winter Mortality. Evaluations of winter The constraints imposed by state statutes or mortality are.based on field checks after the criti- political bodies can directly affect the latitude cal winter period, and usually in areas of winter that a conservation agency can exercise in wild- concentrations. The percentage of such loss in a life management. Colorado is fortunate in that its specific herd area is estimated on the basis of statutes authorize the Wildlife Commission to dead deer counts, and relative to past data. These establish policies and set regulations for wildlife losses are primarily considered to be a function of management. Even with this type of authority, state malnutrition and associated overcrowding and over- wildlife agencies can be subjected to considerable utilization of limited winter ranges, though the pressure through implied threats of alternative amount and character of snow, minimum sustained laws, or even manipulations of budget requests. For temperatures, protective cover and wind are known example, a western state's commission established a factors. Such data impact on regulations per- regulation intended for a three-year longevity, but taining to antlered only or either sex seasons, and after two years it was found to be ineffective, and, formerly on bag limits when we held two and three- in fact, detrimental to that agency's objectives deer seasons. and supportive data justified the repeal or revision of the regulation. However, word was received from 5. Range Analysis. Production and utilization the state legislature that they would set the estimates on key browse species on important winter seasons if the agency's regulations were not con- range areas at one time formed the primary basis sistent. In the political world, it seems that for Colorado mule deer management. Unfortunately, consistency is of higher merit than being flexible this is no longer true, and will be discussed under enough to admit a mistake and correct it! In an- political considerations. During most of the other case a legislative committee handling a con- fifties and sixties, however, range transect data servation agency's budget request subtly suggested provided significant input in regulation determi- a regulation pertaining to the identification of sex nations, and could still do so. on a big game carcass be less restrictive, and it was changed. Two deer seasons were initiated in 1950 primarily on the basis of range conditions in an A major political impact on state wildlife

,?eguZations and the Mule Deer Harvest agencies could be in the offing, pending the findings for two-deer seasons in the early fifties were of courts and the results of appeals in New Mexico quite effective, and license sales increased as a and Montana on nonresident license fees. If non- result. A new philosophy, economically-oriented, residents become entitled to hunt on the same arose. Why give that second deer away, when with license structure that residents do, season regu- increased hunter pressure we could sell a second lations will have to be tailored to meet an in- license at a reduced fee and generate some more creased hunter demand through restrictions on sex '! income? The multiple license was born in 1957, and numbers of harvest and shortened seasons, to and was utilized until 1970. lessen the biological impacts on the big game. The influence of public attitudes, a socio- Many political impacts on regulations are so political consideration, is exemplified by the intertwined that they involve economics, sociology actions of landowners in traditionally bucks only and biology. An example is intra-agency politics areas in the late forties when extensive either where for public relations and economic reasons it sex season regulations were implemented. Many of was decided to set the general season regulations these purists posted their lands against doe in March to facilitate getting the information on hunters, and undoubtedly caused some restraint on opening dates and areas out to the public. This the part of the Colorado Game and Fish Department early setting of seasons was to meet printing dead- in designating additional either sex hunting areas, lines and allow the sportsmen to arrange necessary until some of these same ranchers began to ex- vacation time for hunting. The impact of this perience haystack damages from the burgeoning deer reached to the field level, because winter mortality populations. counts and range transects could not be completed before May due to continuing winter range use and The increases in Colorado license fees effective lack of access, although the numbers of limited in 1976 will result in socio-economic influences on either sex permits would be set in May. This time season regulations. Resident deer license fees schedule has probably been one of the greatest con- have gone from $10.00 to $13.00, while nonresident tributing factors to the decline in obtaining the fees have gone from $50.00 to $90.00. We will indicated biological data. Furthermore, in regard have to experience at least one season under this to legal politics, the attorney general has decreed new structure to evaluate the effect of probable that the agency must have its recommendations for decreased hunter pressure on herd management ob- season regulations available for public inspection jectives, then consider what regulation options 20 days prior to commission action. This means, in will best attain the desired harvest. reality, that the regulations must be written for big game season opening dates and areas in February. HERD SIMULATION MODEL Public safety and welfare are a form of political consideration in setting seasons. For example, For almost 20 years Colorado's deer management in Colorado, to spread the first day of season efforts were directed toward reducing overpopu- pressure and reduce the possibilities of hunter lation~to the carrying capacity of the most fatalities and accidents, the deer season and elk critical factor - the winter range. It was always season were separated in 1971 from their previously stated and generally accepted that the deer could concurrent timing. Though a high percentage of elk come back faster than the browse. The regulations hunters were also deer hunters, they then had to instituted to affect this reduction began with hunt these respective species at different times, either sex seasons, then two deer seasons, and thus reducing the total number of hunters in the finally multiple license seasons (varying from field during one season. True, there was some unlimited additional licenses to one additional economic impact in reduced total license sales, license, with one deer per license to two deer because many hunters, particularly nonresidents, allowed on the second license, and, in some cases, who previously hunted both species could not afford two deer on both the original and the multiple two separate hunting trips, and therefore only hunted license). In addition to multiple bag limits, the one species. times and lengths of seasons were varied to obtain increased harvests. Post seasons were utilized in When archery deer hunting was started in Colo- relatively small areas when deer were on late fall rado in 1948, the bow hunters could hunt on a regular transitional or winter ranges. Since 1963 manage- deer license which was validated for that purpose, ment objectives generally have been either to and if unsuccessful in bowhunting, they could use stabilize the deer herds, or to increase them that license in the regular deer season. In 1961 numerically. an archery deer license was established by the legislature, and if an archer was unsuccessful during Current harvest data alone do not allow an bowhunting season, he could then purchase a regular accurate determination of mule deer populations, deer license and hunt with a rifle. Again, in de- particularly on a statewide basis, due to more siring to divert hunter pressure from the regular variable and restrictive seasons applied under season, a one-and-only hunt concept was established present management practices. Therefore, game in 1974 through regulation, wherein no one could management units have been combined to form data purchase more than one license for a given species analysis units, which are considered to be more during the year. The effect that this had was to realistic total herd year-round habitat. Herd weed the marginal bowhunters out of the archery ranks data can now be analyzed by a computer simulation and put them right back into the more sure-fire rifle of herd structure, as well as the effect of various season. impacts, both real and simulated, on that herd, other factors remaining equal. This type of sys- The biologically-based regulations providing tems analysis is guided by Dr. Jack Gross, U. S.

ReguLations cmd the MdZe Deer Hurvest 90 Fish and Wildlife Service, and conducted by Tom mortality rate of 22 per cent was used from 1963 Pojar, Colorado Division of Wildlife. Systems ana- through 1971, 40 per cent for 1972, 50 per cent in lysis has the potential for indicating the impacts 1973, then 22 per cent from 1974 onward. Using the of regulations on a given herd, whether they be yearling harvest as an index to fawn survival from biologically or politically generated. By plugging the previous winter, the yearling harvests in 1973 in known data for the past several years, certain and 1974 support the indicated increased winter loss causative factors may be indicated as responsible of fawns reported for 1972 and 1973. This ad- for given herd reactions. ditional fawn mortality resulted in a downward population trend in the simulation, which is actually The Uncompahgre Plateau in southwestern Colo- what happened in the field. The alignment of these rado represents a deer herd on which our most com- data with the simulation is probably one of the plete data are available. This herd unit is composed strongest points of this analysis. of two game management units, 61 and 62, comprising deer data analysis unit D-19. The systems model Table 1 lists a comparison of simulated and begins in 1963 and is projected through 1980. Actual reported values for pre- and post-season bucks and harvest data are displayed in Figure 2 relative to fawns per 100 females. The pre-season buck to doe total and buck (antlered) harvest, hunter pressure ratios are simulated above the reported values, as and success ratios from 1950 to 1975. Inasmuch as the regional biologist, Hal Burdick, feels that the complete simulation printout is extensive, only many bucks are missed during these counts. certain details of the analysis will be highlighted here. The alignment of these data lend support to the closeness of the simulation model to the actual herd structure. and even though-. svecific values are not always in agreement numerically, the general trends follow the same curves.

The model indicates a population of this herd right now of approximately 35,000 deer, with a post-season population projection by 1980 of just over 50,000 animals, IF the 1975 harvest of 2,500 is maintained, and IF the system remains stable.

CONCLUSIONS

As important and necessary as biological ...: . management of mule deer is, the various facets of political management may present significant obsta-

I cles to sound wildlife management, and the con- "W straints imposed by politically-oriented regulations a I I I v I I I I/ICm-/oJ- 5 ,a, 8, L.8 10 8, 6, 6 5 6, r, a-sa r to, rr 7- ,to 108 I, 5 I, 1 may have on mule deer herds can now be indicated experimentally through systems analysis with simu- Figure 2. Uncompahgre Plateau (GMU 61 6 62), 1950- lation models, thus sparing the resource from the 1975, deer data. consequences of illadvised or poorly timed impacts within human control. . . Three sets of fawn mortality rates were used The application of systems analysis to simu- in the model, based on field data. A fawn winter lation modeling of wildlife populations is

Table 1. Comparison of simulated and reported values for pre- and post-season buck and fawn to doe ratios on the Uncompahgre Plateau, 1967-75. Bucks per 100 Females Fawns per 100 Females Pre-season Post-season Pre-season Post-season --Year Simulated Reported Simulated Reported Simulated Reported Simulated Reported

91 ReguZatim and the Mule Deer Harvest relatively new. Several states are beginning to LITERATURE CITED explore the possibilities of this system, including the Interstate Deer Herd Study of California and Hunter, Gilbert N. 1959. A hundred years of Colo- Oregon (Salwasser 1975a, Salwasser and Rutherford rado hunting. Colo. Dept. of Game & Fish, Denver. 975), and the Nevada Fish and Game Department 1959 Colo. Big Game Info., p. 2-3. (Glenn Christensen, pers. corn.). Salwasser, Hal. 1975. The interstate wildlife study- Computer analysis is not a panacea, and is only a fresh perspective. Mzuri Drumbeat, 2(16):6-7, as reliable as the data programmed. Simulation 18-22, 24. modeling will not of itself solve the enigma of the mule deer decline in the west, but it can help . 1975a. Interstate wildlife study: identify areas of concern where additional or more Spring 1975 collection. Univ. Calif., Berkeley. reliable data are needed. Interim Rept., 47 p.

and Kenneth E. Rutherford. 1975. Inter- state wildlife study. Data Package #1. Univ. Calif., Berkeley, and Oregon Wildl. Comm. 22p.

~eyubationsand the Mule Deer Harvest RELIABILITY OF MULE DEER POPULATION MEASUREMENTS

Michael L. Wolfe Department of Wildlife Science Utah State University

Abstract

Various methods of enumerating mule deer population trends are reviewed. Naive acceptance of the results of certain "traditional" methods without recognition of their limitations may account in part for recent declines in deer numbers. This probably has occurred in some states where harvest regulations have been formulated primarily from vegetation-based indices. The problems of failure to meet the requisite assumption of population stability in the estimation of demographic parameters from age- structure data are also discussed. Since individual estimates of animal abundance are each based on assumptions of questionable validity, management agencies are cautioned to avoid reliance on a single method or informational input to formulate harvest regulations.

The objective of most deer management programs is deer populations were excessive and damaging range to maintain the largest huntable population possible vegetation as a result of long-standing restrictive which the habitat can sustain in a healthy condition harvest regulations. At that time the reduction and is compatible with other recognized land uses. of deer numbers and protection of their habitat was Achievement of this goal requires two informational a necessary and justifiable consideration. The inputs. One is a knowledge of the vegetation, par- system was useful in effecting liberal harvests to ticularly in terms of the number of animals it can reduce deer numbers, but today - a quarter of a currently support and the effects of plant succession century later - the basic premise is for the most on future species composition and production. At the part no longer applicable. same time, the manager requires knowledge of deer demography (i.e. population trends, reproductive and Harvest regulations, formulated solely on indices mortality rates and the effects of various exploita- of occupancy and utilization, are subject to several tion levels on the population). With this basic serious shortcomings. Differential winter severity premise, the objective of this paper is to examine may greatly influence animal occupancy of a pre- critically the current state of the arts with determined key area and the intensity of utilization reference to the assessment of mule deer population of browse species on that area. Thus, measurements trends. of occupancy and vegetation-use patterns for a given winter may imply spurious population trends. Table 1 summarizes the different approaches and It may be true that the mean level of browse information sources employed to measure deer popu- utilization and pellet group counts may be higher lation trends as a basis for the formulation of over an extended period of high deer densities than harvest levels. Virtually all the western states during a similar period with low densities. However, that I surveyed employ these methods or some subset annual variations in such indices probably reflect thereof. The categorization of methods is not variations in winter weather rather than actual mutually exclusive but depends to some degree upon changes in big game numbers. Hence, they constitute the level of resolution, with which they are employed. a questionable basis for annual decisions on harvest The application, requisite assumptions and limitations levels. Furthermore, these measurements are (by of most of the methods in the second group have been definition) not predictive, but rather terminal or discussed extensively in the wildlife literature and -ex post facto syiiiptoms of a big game animal's impact are reviewed by Davis (1963). Overton and Davis (1969), on its habitat. This contention has been corro- Seber (1973) and others. I will direct my comments borated empirically by Mackie's (1976) findings in here primarily to the first and third approaches. Montana. He concluded that browse surveys appear mainly to provide hindsight and reflect cumulatively Measures of occupancy and utilization events and conditions of the past more adequately than those at the time the surveys are conducted. the past, management agencies in several western states have relied heavily on observed trends It is my opinion that this frequently overlooked in deer occupancy (animal days use) of critical limitation may account:inpart for the decline in winter range areas and their utilization of "key mule deer numbers in some states. A possible browse species" (Aldous 1945, Cole 1959) as indirect explanation of how this could happen is illustrated indices of deer population trends. This system was in Fig. 1 (modified from bey 1972). The straight initiated during an era (the early 19501s), when line I is the scalar relationship between actual

93 ,?r?ZtnbiZitu of Mute Deer Povutation Measurements 1, IkoWsE lrrILIZATI0N 1, HERD COMPOSITION SURVEYS TRENDS A, AERIAL B, GROW A, FAWN-WE RATIOS B, SEX RATIOS 2. ~NDIRECT POPULATION ESTIMATES 2, AGE STRUCTUREOF THE HARVEST A, WINE-IN-RATIO B, FELLET mup cows 3, DEAD DEER SURVEYS

3, ~ERTREND INDICES An WVST TRENDS B, KIduNIT EFFORT ASSUYIPTION: IFPOPULATION PARAMETERS (I , , NATALITY AND WRTAL- ITYf CAN BE MEASURED ACCUR- IFME BIASSES INWLVED IN ATELY AND RELATED TO VARYING THE INDEX REWIN CONSTANT LEVELS OF EXPLOITATION WE .- . . - .- FROM YEAR TO YEAR, CHANGES CAN DETERMINE THE HARVEST BROWSE PLANTS REFLECTS ME IN ME INDEX REFLECT POPP WICH BALANCES THEM, LEVEL OF ME POPULATION, LATION CI-W\IGES, p~~ulationsize dnd reliable index ut population density. Such a correlation might be assumed to exist if measurements of animal occupancy and browse utilization were true indicators of animal numbers or density. The hypothetical relationship (11) is, however, descriptive of the situation, where the indices are derived solely from measurements of animal use in areas of preferred habitat (i.e. "key areas"). At low population levels (A) practically all animals are found in the preferred areas. As population density reaches a saturation point (B) in the areas sampled, no more animals will use the area, even though the population continues to increase. Finally, as density becomes extreme (C), animals utilize less preferred, marginal areas.

Retrospectively. this relationship may be diagnostic of what has happened to deer herds in some states over the past 25 years. Point C could be construed to represent the situation in Utah and other 0 areas of the Intermountain West during the late 1940's POPULATION SIZE when deer numbers were excessive. As herds were reduced substantially by continuing liberal harvests - perhaps back to polnt B - commensurate changes in the llyprtnetical relationships between popula- occupancy and vegetation-use indices were not evident. Figure 1. tion size and vegetation-based indices of population Consequentlb, deer populations in some areas were Relationship I re- reduced belcd desirable levels. trend (modified from Aney, 1972). presents the linear relationship between actual popu- The roregoing arguments should not be misconstrued lation size expected, if measurenlents of animal use as a renunciation of habitat or vegetation-based (i.e. browse utilization and animal days use) were accurate indicators of animal numbers. Xelationsbip measurements per se, inasmuch as these constitute an integral component of a sound management program for 11 might exist when indices are based only on animal use in areas of preferred habitat. See text for fur- any big game species. I would contend, however, that A relationship complementary to the inrerence of population trends in browsing ther explanation. ~nimal>from measurements of animal use represents curve I1 might exist when indices are based solely on a c~~t.ultousand potentially erroneous approach. measurements in non-preferred habitat.

94 Reziabi litU of h2e Dee13 PopuZat ion Measurements More importantly, naive acceptance at face value of than the current winter. This and the fact that the results obtained by these measurements without older pellets may persist for several seasons recognition of their inherent weaknesses may have dictates the use of permanent "swept" plots. Some contributed indirectly to or aggravated population of the benefits of stratification could be realized declines in some cases. The dual approach of by a compromise solution, whereby sampling effort is measuring animal population trends annually in conjunc- allocated on the basis of past patterns of winter tionwithperiodic and more sophisticated vegetational deer distribution. Clusters of plots, as used by measurements, to evaluate long-term trends in range Eberhardt and Van Etten (1956), Smith (1964), and condition, productivity and species composition Stormer et al. (1974), might be employed to vary represents a more realistic approach. sampling intensity on transects of standardized length. Several authors (Eberhardt 1960, Bowden Indices of population trend: et al. 1969, McConnell and Smith 1969) have analyzed the nature of frequency distributions in pellet- As game biologists began to question the adequacy group tallies. The results of these or similar of occupancy and utilization measurements, some states investigations should provide additional information have moved in other directions. One of these was with reference to optimal allocation within density . toward refining fecal pellet-group counts to obtain strata. "estimates" or at least indices of actual deer population levels. The pellet group technique has received Dynamics data: considerable attention in the wildlife literature and has been comprehensively reviewed by Neff (1968). The concept of employing demographic parameters Detailed treatment of the method is not within the in the analysis of deer population dynamics is not scope of this paper, but a few brief comments seem novel, as attested by the classical papers of Taber apropos. and Dasman (1957) and Eberhardt (1960). However, this approach has received renewed attention within The fundamental weakness of the pellet group the past decade, largely as the result of two technique as a source of information for management important developments in wildife science. One is purposes, is human error. This comes as no surprise the increasingly widespread application of the to any manager, who has "picked pellets" at some time cementum annualtion technique for age determination. in his career. Of all the means of collecting data This technique has given game managers the means to on big game animals, this is the most tedious. Even obtain reasonably accurate data on the age distri- if the manager is fortunate enough to have well- bution of large harvest samples from different herd intentioned and responsible field personnel and he can units and relate them by conventional methods of convince them of the necessity for accurate pellet population analysis to varying harvest strategies. tallies, some unavoidable errors will occur. Unfor- The other important development is the advent of tunately, these cannot be rectified and we will pro- computer technology, which has greatly facilitated bably have to live with them in the future. the iterative processes involved in demographic analysis and opened up the field of population Beyond this, the use of pellet group counts as a simulation. population estimator requires certain refinements in addition to those necessary for the application of the Despite the apparent sophistication in this method as a mere index of animal use. Perhaps the approach, its limitations should not be overlooked. most important of these is that of stratifying Referring to Table 1, let us examine the basic sampling allocation. Big game animals are rarely assumption involved in this approach. We assume that distributed randomly or uniformly on winter range it is possible to measure accurately reproductive areas. This is particularly true in the West, where increments to the herd and the mortality or marked topographic variation and associated vegeta- survival rates operating on the population -- tional differences produce more or less distinct strata especially within the female segment -- under varying of differential deer distribution and density, which harvest regimes. If this is possible, we can vary annually in response to winter severity (Edwards determine the level of harvest, which just crops the 1956, Loveless 1967, Gilbert et al. 1970). Sampling annual increment, while allowing for natural variance' in contagious distributions increases with decrements. We will further stipulate that it is density. If differential density strata are con- within the manager's wherewithal to assess reliably sidered in the statistical design of pellet group the recruitment to the population and concentrate counts, sampling intensity can be allocated propor- on the problem of measuring mortality rates. tionally or optimally to the various strata, thereby increasing the precision of the population estimate Given a sample of the relative age frequencies obtained (Siniff and Skoog 1964, Bergerud 1968). It in a population at a point in time, the age-specific might be noted that this generalization is applicable, and total mortality rates operative within the not only to pellet group counts, but also to some of population from which the sample derives can be the other methods of assessing population trends and estimated subject to certain important assumptions: related parameters (e.g. dead deer surveys), listed in Table 1. 1. That mortality and natality have been constant . and the population has remained numerically In theory, sampling effort in pellet counts should constant for some time previous to the point at be allocated on the basis of observed deer distribution which the sample was taken; patterns in the winter immediately prior to the surveys. This implies the use of temporary plots. 2. That the sample accurately reflects the However, western conditions necessitate some departures relative strengths of the various age classes in from the ideal design. Sparse, xerophytic vegetation the population; on many big game winter ranges precludes reliance upon autumnal leaf-fall to conceal pellets of older origin 3. That the method of age determination is accurate.

ReZiabiZity of &le Deer Population Measurements While the iterative procedures involved may differ, (in this case 10 percent). Ironically, if the level the assumptions upon which they are predicated are of harvest were formulated on the implied mortality basically the same. We should be able to satisfy the rate alone, the population decline would be aggra- third condition, given the methods of age determina- -7ated. Given an independent estimate of the rate of tion that are currently available. We also know that population change, the true mortality rate could some age classes, notably fawns and yearlings, are be derived from the implied rate. Paradoxically, differentially vulnerable to the gun and will probably accurate and independently derived estimates of the not be accurately represented in a hunter-killed sample rate of population change are more often than not (Smith et al. 1969, Hayne and Eberhardt 1952, Maguire lacking, and if they were available they would and Severinghaus 19541, but there exist methods for obviate this somewhat circuitous approach to assessing dealing with these biasses (vide Robson and Chapman deer population trends. Without them, however, the 1961). inference of population trends based on survival rates derived from the vertical age structure of a The greatest single bugaboo remains the rigorous population is tautological. and seldom met condition of population stability. The effects of failure to meet this assumption can be The implications of this problem are well known illustrated by a simple demographic convention to population ecologists (Caughley 1966, Eberhardt (Table 2). The strictly hypothetical population shown 1969), but may be overlooked by the manager, below is generated over time from an initial cohort especially when he may be lulled into a false sense of 1000 animals (50:50 sex ratio) of one year of age, of security with the aforementioned advances in age- in which each yearling or adult female produces two determination techniques and computer technology. young (i.e. natality = 50 percent); the mortality Computerized iteration of dynamics data and popu- rate for all age and sex classes is 55 percent. lation simulation techniques can and will not rectify Admittedly, this is not a very realistic represen- biasses inherent in the basic data. tation of act-~almule deer population parameters, since it fails to account for age-specific fecundity This is merely one of numerous problems involved and mortality rates and assumes that all females in the estimation of population parameters from life breed as fawns. These simplistic parameters have tables and related methods. Rarely, if ever, are the been purposely chosen, however, to preserve the histories of the several cohorts represented in a clarity of the point that I am trying to make. time-specific sample of the population indentical as Examining the total number of animals in the popu- represented in Table 2. Hence substantial annual lation over time, it is obvious that the population variations in productivity and winter survival may is decreasing by 10 percent per annum. This is to produce seeming anomalies in the age structure of a be expected in terms of discrepancy between population, which complicate or preclude derivation natality and mortality rates (50 vs 55 percent). of mortality rates. Separation of these effects from the vagaries of sampling effect may be Table 2. Cohort shrinkage in a declining population; difficult. annual mortality rate = 55 percent; natality = 50 percent. See text for further Referring again to Table 2, it was noted that explanation. the mortality rates operative within a given cohort could be determined by examining the relative strengths of that cohort in samples taken at consecutive points in time. Such a horizontal approach is of relatively limited utility for deer management for several reasons. Foremost as the requisite assumption of equal sampling intensity over time. Obviously, this assumption does not obtain, when the degree of removal varies annually due to differential harvest regulations and/or differences in weather conditions during the hunting season. Certainly, differences in the relative vulnerability of various age classes must be taken into account here also. Moreover, stochastic variations in natural sources of mortality (e.g. winter losses) will affect the apparent strength of a given age class (especially that of yearlings) and thereby preclude estimation of mortality rates by this method.

CONCLUSIONS

In summary, we find that despite the staggering The actual mortality rate operative withil. the resources and effort expended annually, real accuracy population is reflected in the shrinkage over time and precision in the enumeration of mule deer popu- for a cohort, born in any given calendar year. lation trends remain elusive. Looking to the future, However, if one attempts to ascertain the mortality I do not see any pat solutions to the problem on the rate from the age-class frequencies in a vertical immediate horizon. A few years ago, some biologists segment of the population in a given calendar year, hailed remote sensing (Croon et al. 1968, Graves (say year 9) the implied mortality rate thus et al. 1972, Parker and Driscoll 1972) as the paragon obtained underestimates the true mortality by a of the future. To date at least, this technique has factor equivalent to the rate of population change not lived up to original expectations. Continued

Re Ziabi Zity of Mule Deer Population &asurements development of remote sensing, especially the Cole, G. F. 1959. Key browse survey method. Proc. implemefitation of more sophisticated hardware and West. Assoc. State Game and Fish Comm. 39:181- innovative approaches, may ultimately provide more 186. reliable results. However, this will undoubtedly require several years of additional research and devel- Croon, G. W., D. R. McCullough, C. E. Olson, Jr., opment. and L. M. Queal. 1968. Infrared scanning techniques for big game censusing. J. Wildl. 1. Management agencies should not rely on a single Manage. 32(4):751-759. method or source of information to assess deer population trends and formulate harvest regulations. Davis, D. E. 1963. Estimating the numbers of game Individual estimators of animal abundance and related populations. Pages 89-118 H. F. Mosby, ed. demographic parameters are each based on assumptions Wildlife Investigational Techniques. The of questionable validity. Moreover, problems of Wildlife Society, Washington, D.C. sampling error reduce precision and further confound the reliability of population estimates. Given these Eberhardt, L. L. 1960. Estimation of vital circumstances, the only feasible alternative is to characteristics of Michigan deer herds. Report weigh carefully the results obtained by several 2282, Game Div., Mich. Dept. of Conserv., independent indices and the effects of inherent Lansing. 192 pp. biasses on these indices to derive a qualified "best guess" of population levels on an annual basis. Eberhardt, L. L. and R. C. Van Etten. 1956. Evalu- ation of the pellet group count as a deer 2. Lacking any single, totally reliable census census method. J. Wildl. Manage. 20(1):70-74. method, a concerted estimate should be directed toward . 1969. Population analysis. Pages 457- quantifying the fraction of a deer population that is 496 & R. H. Giles, ed. Wildlife management removed annually by hunting. The need for information techniques. The Wildlife Society, Washington. D.C. of this nature seems singularly appropriate in an era of increasing demands - both on the part of the Edwards, R. Y. 1956. Snow depths and ungulate hunting public as well as non-consumptive interest abundance in the mountains of western Canada. groups - to know the magnitudeand impact of various J. Wildl. Manage. 20(2):159-168. harvest strategies and natural decrements on deer Gilbert, P. F., 0. C. Wallmo, and R. B. Gill. 1970. populations. One possible approach to this problem Effect of snow depth on mule deer in Middle Park, would be estimation of "harvest rates". Ideally, this Colorado. J. Wildl. Manage. 34(1):15-23. would involve the admittedly difficult task of large- sca7.e tagging programs on summer ranges and the use Graves, H. B., E. D. Bellis, and W. M. Knuth. 1972. of a reward system to insure reporting most or all Censusing white-tailed deer by airborne thermal of the tagged animals that were harvested. The infrared imagery. J. Wildl. Manage. 36(3): recovery rates thus obtained would provide an index 875-884. of the fractionofthe population which is harvested. Hayne, D. W. and L. Eberhardt. 1952. Notes on These rates could be correlated to differential harvest the estimation of survival rates from age dis- regulations, levels of hunting pressure, deer vulner- tribution of deer. Paper presented at 14th ability as related to topography and access on Midwest. Wildl. Conf. (unpubl. ms.) different herd units. Comparison of the hunting removal rate under a spectrum of harvest strategies Loveless, C. M. 1967. Ecological characteristics Colorado Div. with estimated losses from other factors may serve to of a mule deer winter range. establish the proper perspective for the direction of Game, Fish and Parks, Tech. Publ. No. 20. 124 pp. future research on the measurement of mule deer population trends. Mackie. R. J. 1976. Evaluations of range survey methods, concepts and criteria (effectiveness of the key browse survey method). Montana Game LITERATURE CITED and Fish Dept. P-R Proj. Rep., W-120-R-6. 20 pp. Multilith. Aldous, C. M. 1945. A winter study of mule deer in Maguire, F. and C. W. Severinghaus. 1954. Nevada. J. Wildl. Manage. 9(2):145-151. H. Wariness as an influence on age composition of New York Fish and Game Aney, W. W. 1972. Statistics as applied to wildlife deer killed by hunters. resource management. Proc. Western Assoc. Game J. l(1) :98-109. and Fish Commissioners 52:272-289. McConnell, B. R., and J. G. Smith. 1970. Frequency Bergerud, A. T. 1968. Numbers and densities. Pages distributions of deer and elk pellets. J. 21-42 & F. B. Golley and H. K. Buechner, eds. Wildl. Manage. 34 (1) :29-36. A practical guide to the study of the productivity Neff, D. J. 1968. The pellet count technique for of large herbivores. IBP Handbook No. 7. Black- A well Scientific Publications, Oxford. big game trend, census, and distribution: review: J. Wildl. Manage. 32(3)597-614. Bowden, D. C., A. E. Anderson, and D. E. Medin. 1969. Frequency distributions of mule deer fecal group Overton. W. S. and D. E. Davis. 1969. Estimating the numbers of animals in wildlife populations. counts. J. Wildl. Manage. 33(4):895-905. Pages 403-455 in R. H. Giles, ed. Wildlife Caughley, G. Mortality patterns in mammals. Ecology management techniques. The Wildlife Society, Washington, D.C. 47(6) :908-918. LITERATURE CITED (Continued)

Parker, H. D., Jr., and R. S. Driscoll. 1972. An experiment in deer detection by thermal scanning. J. Range Manage. 25(6):480-481.

Robson, D. S. and D. G. Chapman. 1961. Catch curves and mortality rates. Trans. Am. Fish. Soc. 90(2) : 181-189.

Seber, G. A. F. 1973. The estimation of animal abundance and related parameters. Griffin, London. 506 pp.

Siniff, D. B., and P. 0. Skoog. 1964. Aerial censusing of caribou populations using stratified random sampling. J. Wildl. Manage. 28(2): 391-401.

Smith, A. D. 1964. Defecation rates of mule deer. J. Wildl. Manage. 28(3):435-444.

Smith, R. H., T. J. McMichael, and H. G. Shaw. 1969. Decline of a desert deer population. Arizona Game and Fish Dept. Wildl. Digest, Abstract 3. 8 PP.

Stormer, F. A., T. W. Hoekstra, C. M. White, and C. M. Kirkpatrick. 1974. Assessment of population levels of white-tailed deer on NAD Crane Purdue Univ. Agric. Exp. Stn. Res. Bult. 10. 11 PP.

Taber, R. D., and R. F. Dasman. 1957. The dynamics of three natural populations. . of the deer Odocoileus hemionus columbianus. Ecology 38(2) : 233-246.

Reliabilitb of MULE Deer PopuZation Measurements 98 MULE DEER MANAGEMENT MYTHS AND

THE MULE DEER POPULATION DECLINE

R. B. Gill Section Chief, Big Game Research

Colorado Division of Wildlife Wildlife Research Center P. 0. Box 2287 Fort Collins, Colorado 80522

Abstract

This paper entertains the thesis that a general decline in mule deer numbers in the West is a myth. Conclusive evidence of such a decline is lacking because there are no real estimates of numbers of mule deer in western United States. Inadequate census methodology, insufficient knowledge of mule deer ecology, and impossible staffing assignments combine with a tradition of uncritical acceptance of new ideas and techniques to produce and perpetuate the myth of the mule deer decline.

INTRODUCTION

The prevailing opinion among wildlife managers fingers of one hand, he has probably been counting in the western United States is that mule deer popu- big game animals. As a science, the determination lations in the West have been declining since the of wild animal populations has gotten little beyond early 1960's (Sandfort 1968; Greenley 1968). the point where we can count up to multiples of the Evidence cited in support of this hypothesis includes fingers on both hands. " This statement, true in declining harvests, erratic but generally declining 1946, remains a reasonable summary of the state of deer counts on trend areas, reduced grazing pressure the art in 1976. With respect to the great mule on "key browse plants" within "key areas", and in- deer decline we should ask ourselves, where are the tuition. It is my contention that the great mule numbers? If they exist, what is the nature of their deer decline is a myth, as are many of the corner- quality? stones of evidence cited in proof of the decline. After reviewing the pertinent literature, I am This does not mean there hasn't been a western- convinced there are no valid estimates of numbers of wide mule deer decline. It simply means the evidence free-ranging mule deer on any large portion of for this thesis is inadequate or lacking, and there- western deer range. There are published figures of fore the conclusion of a general decline in mule deer numbers in various western states such as deer numbers is speculative or "mythical". The 200,000 in Washington (Lauckhart 1968) ; 300,000 in definition of a myth as used in this paper is: "a Colorado (Colo. Div. Wildl. 1974; Meyers 1975), etc. belief given uncritical acceptance by the members of However, these figures are not estimates but, rather, a group, especially in support of existing or are guesses devoid of reliable, quantified substan- traditional practices and institutions" (Gove 1961). tiation. The bulk of the evidence for a general mule In this context, not only is the phenomenon of a deer decline comes from indirect information gener- mule deer decline a myth, but so also are some of ated from sources such as: trend counts, harvest the most cherished "principles" of mule deer manage- estimates, and range use estimates. In addition, ment. The purpose of this paper is to examine some there is also the evidence of opinion, intuition, or of the more persvasive and invidious mule deer manage- "the fieldman's savvy". Let's look at these sources ment myths and relate them to the myth of the great individually and see what sense (or nonsense) can be mule deer decline. made from them.

MULE DEER MANAGEMENT MYTHS Trend Indexes to Deer Abundance

Myths of Mensuration Tracking populations of wild animals through The Numbers Game space and time has always been an elusive wildlife management goal. In the 1930's when the myth of Some time ago Cronemiller and Fischer (1946: 349) professional wildlife management was born, census wrote . . "As far back as the time when aboriginal was accorded primacy in the hierarchy of things to man learned to count by tallying things on the do in order to properly manage wildlife (Leopold

99 MuZe Peer Mm,crgement Myth 1933). W. P. Taylor (~eopoldet al. 1938:47) spoke is given to measuring the extent of their vari- rather vigorously to this point when he declared . . . ability. In other words, pre-designed, statisti- "any wildlife management worthy of the name will be cally logical sampling strategies are seldom difficult or impossible until we develop satisfactory employed. In addition, few wildlife managers have methods of inventory. I' considered the appropriateness of the probability models describing frequency distributions of these There followed an initial flurry of activity to parameters; a binomial distribution is usually develop census techniques to estimate total numbers assumed. Recent tests suggest the simple binomial of deer (e.g. Bennett et al. 1940; Erickson 1940; distribution is not the most appropriate model Hahn 1949; Rasmussen and Doman 1943). But total (Johnson 1976) . estimates proved to be laborious and costly, so new approaches were sought. Most western states Consider also some of the potential biases ultimately settled on indexes called "trend counts." encountered in trying to measure these variables The idea was to select a "key area" for counting. (Paulik and Robson 1969). First, there is good This area was presumed to be representative of a reason to suspect a detectability bias while larger area of interest. Annual counts of deer were sampling sex and age ratios of deer populations. made on the key areas and compared to previous My own experience and that of others (Wallmo 1964; counts. Fluctuations in "key area" counts were Dasmann and Taber 1956; Poux 1972) suggests that assumed to proportionally reflect fluctuations in fawns and does are likely to be more easily detected deer populations inhabiting larger areas. than bucks except possibly during the rut when the reverse may be true. If this is the case then The problem with trend counts lies in their population classification counts may produce false implicit assumptions. First, no one area is ever estimates of population composition. But the extent representative of another (Eberhardt 1963). If of such bias remains unquantified, as does the there is one attribute common to all aspects of variability of the bias over time. biology it is infinite variation. Hence, the first assumption is both absurd and impossible. Secondly, A second consideration is the possibility of sample data (i.e. trend counts) tell us only about bias in the reported sex and age structure of the the sample, not about the real population, unless a harvest (Eberhardt 1971; Coe 1974). Most western relationship has been established. This has never states use data from either hunter survey or check been done with trend counts. Consequently, faith stations to estimate the harvest structure. Both in the extrapolation is unjustified. Yet no myth sources are susceptible to bias. First, there of mensuration occupies a more hallowed position in could be a tendency for hunters to errantly report mule deer management folklore. killing a buck when they actually killed a doe or a fawn (Menzel 1968). Second, not all hunters stop It is my opinion that trend counts were widely at check stations, even if they are required by law adopted because of two predisposing conditions. to do so. It is possible that hunters with mature First, trend counts - especially when conducted from bucks submit to checking more readily than those aircraft - are relatively easy and inexpensive. with fawns or does. Neither source of bias has been Second, historically in the wildlife profession, adequately evaluated (Neilson and Williams 1968). there has been no truly effective forum for critical reviews of new ideas or techniques in wildlife Finally, the estimates of total mule deer ecology, so trend counts gained respectability only harvests are also subject to reporting bias by because so many people unquestioningly adopted them. hunters. In Idaho this source of bias was checked by comparing the known kill of individual hunters to their respective reported kills. Results indicated Harvests as Indexes to Population Trends the estimated statewide harvest was inflated by 16 percent because a portion of the unsuccessful Kill statistics have long been used as an index hunters reported killing a deer when they had not to deer abundance. The degree of apparent sophisti- (Neilson and Williams 1968). All of these questions cation has varied from mathematical projections of taken together cast considerable doubt on the total populations based upon sex and age structure reliability of population estimates generated from of the pre- and post-harvest population, sex and age population structure and harvest data. structure of the harvest, and total harvest (Dasmann 1952; Boyd 1970; Aney 1972; Lipscomb 1974; What can be said then of using harvest data Seber 1973) to simple comparisons of annual harvest by themselves as indications of population trend. fluctuations and direct extrapolations to deer When one considers all of the variables other than population changes (Greenley 1968; Hancock 1968). changes in population density that can cause fluctuations in harvests it is perplexing that this In the case of mathematical projectians from myth has persisted so long (Longhurst et al. 1976). change-in-ratio and harvest data the result is only Harvests can be expected to vary in response to a as good as the data used in the calculations. In bewildering array of factors unrelated to deer most applications of this technique the data (pre- density. Among the more obvious are weather; and post-season sex and age structure of the harvest; changes in season length, type (antlered only, and total harvest) are all treated as absolutes hunter-choice, etc.), and bag limits; hunter (Hanson 1963). Seldom are they considered as distribution; hunter experience; land access; other variables, but when they are and when this variation concurrent competing sources of recreation; etc. is included in mathematical projections , the Each factor can directly influence harvest totals, estimates can be ridiculously imprecise (Wallmo 1964). and they also can interact with each other in Also, because the parameters are frequently con- multiple combinations to produce complex and unpre- sidered to be absolutes, little serious attention dictable effects. Consequently, it is unreasonable

Mule Deer Management Qths to assume that harvest trends consistently all their roe deer and to replace them by others mirror population trends. But even if they did, one introduced from districts with stock of superior would have to know a priori what the real population quality. In all cases, despite the fact that our was doing before the relationship was obvious. figures were available as a guide, the number of animals actually killed far exceeded the most Intuitive Index or the Fieldman's Savvy optimistic estimate."

Somehow through the years a persistent myth So much for the myth of the fieldman's savvy, developed in which the intuitive judgment of the but for those of you who may be skeptical that "man in the field" was attributed a degree of high these are just isolated events, I invite you to reliability which it did not deserve. Bump review Andersen (1961). (1943:324) summarized this development as follows: "Beset by an ever mounting pressure to initiate In summary it may be said that current esti- management activities and produce results, in many mates of mule deer population levels in the West cases they [game managers] were forced to fall back and extrapolations to historic trends are not on so-called practical measures based on individual reality, but myth. This is said because the methods experiences and keen observations, rather than on from which the information was generated do not results gained through careful scientific tests." stand the test of critical evaluation, but rather have been accepted simply because they were in- But the fieldman's savvy has been woefully in- stitutionalized in print. adequate when it has been put to a test. The following pertinent examples clearly illustrate this point. On July 12, 1924 an outbreak of foot and MYTH OF THE BROWSER mouth disease was discovered among deer in the Stanislaus National Forest in California. A decision Several of the western states employ an in- was made to exterminate the Stanislaus herd to direct method for estimating changes in relative eradicate the disease. An initial poisoning program mule deer abundance. These procedures have been proved ineffectual, so shooting was decided upon as variously called "range analysis methods", "range the next alternative. In order to properly staff condition and trend transects", "browse production and prepare for such an enormous task, some pre- and utilization transects", etc. (Sandfort 1968; liminary information was needed about the estimated Hancock 1968). But all methods have certain size of the population. The best experts available common characteristics. Key areas are selected were contacted and asked to estimate the deer popu- which supposedly represent areas critical to the lation level. These estimates ranged from 6,000 to survival of deer populations. Within the key areas, 10,000 deer. Shooting commenced on December 1, 1924 key browse species are selected which are supposed and continued for almost a year, though most of the to define the capability of the key area to support killing was accomplished in the winter months while deer. Finally, transects are established within deer were concentrated. The final tally of deer the key browse types within the key areas. These -shot was 22,214, and there were still live deer transects purportedly provide indexes to fluctua- remaining (Keane 1926) . Thus, the maximum estimate tions in mule deer food production and utilization based on the fieldman's sawy was only 45 percent of from year to year (Denney 1962). There are several the minimum true population. deficiencies in this approach to carrying capacity and deer abundance. First, is almost total In 1949 a Game Research Farm was established in disregard of the principles of statistical sampling KalQ, Denmark. In 1950 it was decided to eliminate methodology. In most cases transect locations are the entire stock of roe deer resident on the farm and selectively placed rather than allocated by some to replenish it with fresh stock. The entire area technique which minimizes personal bias (Eberhardt contained approximately 1,000 ha. Within this 1971). Because of this neglect the resultant data 1,000 ha there were two woodlots of about 170 ha are really pertinent only to particular plants and each, the remainder being farmland. Before the transects on which they are measured. No legitimate shooting program was initiated, various local experts extrapolations can be made to general populations were polled to estimate the size of the roe deer of browse plants growing on key areas nor can population in order to better understand the extrapolations be made from key areas to general magnitude of the task. The consensus was that winter range complexes. approximately 70 roe deer inhabited the farm. When the last deer was shot the total tallied was 213 - But even more insidious is the primary 3 times the original estimate (Andersen 1953). assumption basic to the entire procedure. This Commenting on this experience in a later publication assumption is that mule deer are primarily de- Andersen (1962:72-74) said . . . "without experience pendent upon browse for winter survival (e.g. of such a campaign it is impossible to form any idea Julander 1937; Carhart 1941a; Hill 1956; Einarsen of the ability of roe deer to escape detection. The 1956). The "myth of the browser" is one of the complete failure of our prior attempt at estimating most ancient, persistent, and pervasive of all mule herd size is most striking, especially since this deer myths and continues even today to dominate initial estimate was made by the forestry and game most mule deer management philosophy and activity. personnel at Kale who had known the two woods for years and who had spent part of every day there. The The "myth of the browser" developed in much result was greeted with widespread incredulity, and the same way as most mule deer myths. Methods to I believe that many people considered that our determine what deer eat were chosen uncritically, initial counting methods were faulty. However, con- and the results obtained were accepted uncritically. firmatory results were obtained when the owners of Early information on mule deer foods was based three or four other Danish estates decided to kill primarily on four methods; observations of free- ranging wild deer (Dixon 1928), stomach content 1969). The conclusion of Bergerud and Nolan analyses (Dixon 1934), snow-trailing (Carhart 1941b), (1970:350) that . . . "caribou are not specialized and observations of feeding sites for evidence of feeders but are generalists. They appear grazed plants (Lovaas 1958). Little critical opportunists and when necessary eat most kinds of thought was devoted to potential biases in method- vegetation", is equally germane to mule deer. ology that might seriously distort the results. Some might argue that although deer may eat a Wallmo et al. (1973:562) tested the deer variety of foods, there is still a relationship observation method and the feeding site method between trends in the production and utilization under semi-controlled conditions. They remarked ... of browse and trends in deer numbers. If this "at best, most of the major forage species used by contention is true it still remains to be deer might be identified by the grazing-minutes or demonstrated. One of the few attempts at such a the feeding site method. Quantification, however, demonstration (Anderson et al. 1972) was incon- can be considerably in error." The grazing clusive. The considerable evidence that browse observation method particularly favors detection of twigs may not be preferred, but contingency food, browse use over other forage species (Wallmo et al. complicates the interpretation of browse-use 19 73) . measurements with respect to deer population levels (Short 1969). Improved forage conditions con- Biases in stomach content analyses have been ducive to population increases may be accompanied reported by several authors (Norris 1943; Bergerud by decreased browse use. Poor forage conditions and Russell 1964; Scooter 1966, Murie 1933; Eastman conducive to population decreases may result in 1974). Norris (1943:249) compared the results of increased use of browse. Meanwhile, growing domestic sheep feeding trials and rumen content conditions for browse species can either accentuate analyses where known diets were offered. Among his or mask the evidence of use irrespective of the several conclusions, he reported ... "stomachs may direction of change in the deer population. Con- show large percentages of coarse browse which has sequently the deficiencies of sampling methodology been eate~over a period of days leading the and inadequate knowledge of the ecology of mule analyst to conclude that browse is the chief article deer on shrub ranges render statewide or region- of the diet, while, in reality, rapidly digested, wide deer population trend evaluation with this succulent forage may have been consumed in much method both meaningless and mythical. larger amounts ."

Bergerud and Russell (1964:813) reached similar MYTH OF THE MULTI-PURPOSE MAN conclusions in similar studies with caribou. They stated "There appear to be two serious biases in In the foregoing sections, technique de- abundance comparisons of plant groups and plant species between groups in rumen contents as a result ficiencies were related to the evolution of mule In this section attention of differential digestion: (1) plant groups are not deer biological myths. proportionally represented in the larger (identified) will be directed toward an organizational and philosophical deficiency which serves to per- fragments and the smaller (unidentified) particles, and (2) the identifiable fragments of some plants petuate the biological myths. Most western states did not really get into comprehensive wildlife disappear more quickly than others. " management programs until after the passage of the Wildlife Restoration Act or the Pittman-Robertson Snow trailing results are susceptible to the same kind of shrub bias as the other 3 methods but Bill of 1937. This act provided necessary funding to expand state programs, which historically had for different reasons. Snow cover profoundly influences the forage choices of deer. Smith et al. been "protectionist" or law enforcement oriented, to include detailed investigations of the biology (1975) reported that grass and forb consumption increased in the diets of tame deer and shrub and ecology of game species. Initially, new personnel were hired specifically as game consumpl .>ndecreased as snow melt increased grass- Their responsibilities were to acquire forb availability. Bergerud and Nolan (1970) biologists. observed the same general phenomenon while studying the knowledge requisite to effective management food habits of tame caribou. In Middle Park, strategies for realizing the harvest potential of these species. Colorado, diets of tame deer shifted abruptly over a 24 hr period following a 6-8 inch snowfall. Shrub use was accentuated and grass-forb use diminished In the 1940's and early 1950's the endeavor following the snowfall (Carpenter et al. 1976, and amount of knowledge generated was truly impressive. With respect to deer, serious unpublished data). These studies suggest that snow sample trailing can be expected to over-emphasize the attempts were made to population dynamics winter-long importance of browse, while de- parameters and habitat attributes (Cronemiller emphasizing the role of grasses and forbs. and Fischer 1946; Carhart 1941b; Edwards 1942; Longhurst et al. 1952; McCain 1948). Then early in the 1950's, a trend began to combine the All of the foregoing suggests that the over- simplified clascification of deer as browsers is duties of trapper, game warden,and game damage erroneous and misleading. But even if data derived officer into a single position. In Colorado from these different techniques were taken at face this position was called the Wildlife Conservation value, they st111 don't justify the over-simplifi- Officer (Feltner 1961), and the standards for cation. Several studies which were based upon these recruitment and salaries were raised to reflect increased professionalism. Activities funded various methods belie the generalization that deer by Federal cost-sharing programs (Pittman- ire predominant 1 y browsers (e.g. Dixon 1934; Leach Robertson) were still left to the game biologists. 1956; Nichol 19 36; Dunkeson 1955; Nellis and Ross A long-simmering conflict between the game critically, and objectively. This process is not biologists and the wildlife conservation officers so used now. flared into open hostility over who should be responsible for game management functions. Eventually 2. The individual states with mule deer in Colorado this conflict was decided in favor of populations must establish goals and priorities the Wildlife Conservation Officers and their duties for obtaining minimum information requisite to were expanded to include game and fish management. realistic management decisions. The first priority These developments marked the birth of the multi- within these programs is to develop basic popula- purpose man concept. tion inventory systems (Eberhardt 1971). These systems will have to consolidate the best knowl- Today these responsibilities have been expanded edge of statistics and biology to insure a high still further to include information and education, probability of obtaining real and generally environmental impact assessment, assistance in pertinent data. Initially this information will county land use planning, interagency liaison, and be crude because that is the current status of non-game and endangered species management, to name the art (Overton 1971). Much research is needed only a few. In short it became impossible to do all concerning mule deer behavior, remote sensing things well. Responsibilities simply expanded be- technology, and biometrics to significantly yond capabilities and staffing. The result was that advance this status. something had to suffer. That "something" in Colorado has been wildlife management. 3. It is clear to me that the multi-purpose man concept, as it is employed in Colorado, at The organizational structure required that least, can not possibly produce mule deer manage- wildlife population and habitat data and management ment data of sufficient quality and quantity to recommendations originate with the Wildlife support fundamentally sound management programs. Conservation Officer level. Since there was little These programs are a full-time job in themselves. time available to devote to wildlife population and At least 3 alternatives are available: (a) Remove habitat measurements, only those techniques which wildlife management from the several responsi- were expeditious and simp1 e were retained. The bilities of the Wildlife Conservation Officer and result was the development and institutionalization reduce the WCO staffing levels. Replace these of the myths of mensuration and the myth of the WCO staff reductions with local wildlife manage- browser. In the process, a new myth became part ment biologists who design and direct mule deer of our wildlife heritage - the myth of the multi- management surveys. These mule deer management purpose man. When one considers the infinite survey teams could be staffed by temporary complexity of ecosystems it is incredible that a employees or with WCO's on temporary, seasonal reasonable person could still believe that any assignments; (b) Increase statewide staffing of single individual could do an adequate job of wildlife biologists without reducing WCO staffing. wildlife management alone, disregarding the re- The wildlife biologists could work in teams over mainder of his multitudinous functions. large areas or regions to secure management data; (c) Plan all activities within a WCO district on Still, the myth persists and meaningful wild- a priority basis with wildlife management (and life management progress is stymied. In the minds specifically mule deer management) receiving a of administrators, politicians, and the general very high priority. Then allocate money and man- public, the image and the myth of the multi-purpose power necessary to adequately execute those plans. man, who does all things competently, is firmly entrenched. With a heritage of inappropriate These suggestions are over-simplified and methodology in his tool bag, and too little time to tentative. Reorganizing the bureaucracy is apply it, he understandably has resorted to this futile if we continue to do the wrong things under reputation to carry him through the trials of the new organization. At the heart of the present decision-making. It takes only the concurrence of issue is the fact that we have not employed in- several such persons to turn an unsubstantiated ventory systems capable of detecting whether or opinion into an accepted truth. The "fact" of a not deer populations are changing statewide or western-wide decline in mule deer populations rests region-wide. To have done so would not assure on such a foundation. that we would then make the best management decisions; the problem of human sociology compounds the infinitely complex ecological problems MYTH MANAGEMENT that confront us in wildlife management. However, it would increase the possibility for realistic, If, by now, you accept the original thesis of objective problem analysis. this paper - that the assumption of a decline in mule deer numbers in the West and much of mule deer Meanwhile, we should be forewarned by Overton management methodology is mythical rather than (1971:404): "Complexity is the price of realism factual - then what can be done to extricate manage- and the present degree of realism is none too ment philosophy and practice from counter-productive great." There is no pat method for estimating traditions? I suggest the following prescriptions deer numbers over large areas. If, as this as steps in the right direction: symposium suggests, it is important to have such information, we must face our responsibilities 1. Establish a tradition of critical evalua- more rationally and objectively. tion of wildlife ecological principles, theories, and techniques. A necessary corollary is to use It is important, first, that we recognize that the education process as a forum to encourage we are a large part of the problem (Anderson 1962). novice wildlife ecologists to think analytically, We have been too eager to believe, too quick to

103 Mute Deer Management Myths apply, and too busy to think! Cronemiller, F. P., and G. A. Fischer. 1946. Censusing a deer herd by sampling methods. N. Amer. Wildl. Conf., Trans. 11:349-354.

LITERATURE CITED Dasmann, R. F. 1952. Methods for estimating deer populations from kill data. Calif. Fish and Andersen, 3. 1953. Analysis of a Danish roe-deer Game 38(2) :225-233. population (Capreolus capreolus L.) based upon extermination of the total stock. Danish Rev. , and R. D. Taber. 1956. Determining Game Biol. 2:127-155. structure in Columbian black-tailed deer populations. J. Wildl. Manage. 20(1):78-83. . 1961. Biology and management of roe-deer in Denmark. La Tarra et la Vie 1:41-53. Denney, R. N. 1962. Browse transect analysis and application. Colo. Dep. Game and Fish. Fed. 1962. Roe-deer census and population . Aid Quart. Rep. (April). Proj. W-101-R-4; analysis by means of modified marking release WP-3, Job 3. pp. 51-96. technique. pp. 72-82, E. D. le Cren, and M. W. Hodgate (eds .) The exploitation of . Dixon, J. S. 1928. What deer eat. Amer. For. and natural animal populations. Blackwell For. Life 34(411):143-145. Scientific Publ., Oxford. 399 p. 1934. A study of the life history and Anderson, A. E., D. E. Medin, and D. C. Bowden. . food habits of mule deer in California. Part 1972. Mule deer numbers and shrub yield - 11. Food habits. Calif. Fish and Game 20(4) : utilization on winter range. J. Wildl. Manage. 315-354. 36(2) :571-578. Dunkeson, R. L. 1955. Deer range appraisal for Anderson, J. M. 1962. Can biologists break the the Missouri Ozarks J Wildl Manage. bottleneck? N. Amer. Wildl. Conf., Trans. . . . 19 (3) :358-364. 27:479-484. Eastman, D. S. 1974. Procedural aspects of moose Aney, W. W. 1972. Statistics as applied to wild- rumen analyses. Can. Field-Natur. 88:331- life resource management. W. Assoc. State 335. Game and Fish Comm.. Proc. 52:272-289. Eberhardt, L. L. 1963. Problems in ecological Bennett, L. J., P. F. English, and R. McCain. 1940. sampling. Northwest Sci. 37(1):144-154. A study of deer populations by use of pellet group counts. J. Wildl. Manage. 4(4):398-403. . 1971. Population analysis. pp. 457-495. in R. H. Giles, Jr. (ed.). Wildlife manage- Bergerud, A. T., and L. Russell. 1964. Evaluation - ment techniques. The Wildl. Soc., Wash. of rumen food analysis for Newfoundland caribou. D.C. 633 p. 3. Wildl. Manage. 28:809-814. Edwards, 0. T. 1942. Survey of winter deer range , and M. J. Nolan. 1970. Food habits of hand- Malheur National Forest, Oregon. J. Wildl. reared caribou Rangifer tarrandus L. in Manage. 6(3) :210-220. Newfoundland. Oikos 21:348-350. Einarsen, A. S. 1956. Some aspects of mule deer Boyd, R. J. 1970. Elk of the White River Plateau, management. pp 461-482. in W. P Taylor Colorado. Colo. Div. Game, Fish and Parks . . (ed.) The deer of North America. The Tech. Publ. 25. 126 p. . Stackpole Co., Harrisburg, Pa. and the Wildl. Manage. Inst., Wash. D.C. 668 p. Bump, G. 1943. Wildlife management - fact and fancy. N. Amer. Wildl. Conf., Trans. 8:323- Erickson, A. B. 1940. Notes on a method for 328. censusing white-tailed deer in the spring and summer. J. Wildl. Manage. 4(1):15-18. Carhart, A. H. 1941a. What deer eat; by species, by season, by range and by preference. Amer. Feltner, G. 1961. A look back: a 65 year history For. 50(8) :383-385. of the Colorado Game and Fish Department. Colo. Game and Fish Dep. Annual Rep. 65 p. . 1941b. Report of the deer-elk survey 1938-1941. Part I. Deer food requirements in Gove, P. B. (ed.). 1961. Webster's third inter- Colorado. Colo. Game and Fish Corn. Pittman- national dictionary of the English language Robertson Proj Colo. 4-R. 28 p. . unabridged. G. and C. Merriam Co., Publ. Springfield, Mass. 2662 p. Coe, R. J. 1974. The causes of bias in white- tailed deer kill data. M.S. Thesis. Virginia Greenley, J. C. 1968. Major factors influencing Polytechnic Institute and State Univ., mule deer population and harvest trends since Blacksburg. 84 p. 1962. W. Assoc. State Game and Fish Corn., Proc. 48:258-259. Colorado Division of Wildlife. 1974. The strategy of today for wildlife tomorrow. Colo. Div. Wildl. Denver, Colo. 103 p.

kt2e Deer Management Myths Hahn, H. C. 1949. A method for censusing deer and Menzel, K. E. 1968. Accuracy of hunter reporting its application in the Edwards Plateau of on big game harvest questionnaires . Central Texas. Texas Game, Fish, and Oyster Comm. Mtns. and Plains Sec. The Wildl. Soc., Trans. Feb. 1949. 24 p. 13:lO.

Hancock, N. V. 1968. Major factors affecting mule Meyers, B. 1975. Deer hunters promised bigger deer population and harvest trends in Utah herds in future. The Denver Post. Dec. 21. since 1962. W. Assoc. State Game and Fish p. 74. Comm., Proc. 48:245-252. Murie, 0. J. 1933. Some observations in big game Hanson. W. R. 1963. Calculation of productivity, studies. pp. 34-38. & T. G. Taylor and B. survival, and abundance of selected verte- C. Pittman (eds.). Game-management develop- brates from sex and age ratios. Wildl. Monogr. ments and needs. Utah Agr. Exp. Sta. and 9. 60 p. Ext. Serv. Misc. Publ. 10. 51 p.

Hill. R. R. 1956. Food habits and range manage- Neilson, A. E., and R. M. Williams. 1968. Major ment of the mule deer. pp. 393-414. in W. P. factors influencing mule deer populations Taylor (ed.). The deer of North ~merica. and harvest trends since 1962 - Idaho. W. The Stackpole Co., Harrisburg, Pa., and the Assoc. State Game and Fish Corn., Proc. 48: Wildl. Manage. Inst., Wash. D.C. 668 p. 232-236.

Johnson, E. G. 1976. Some probability models for Nellis, C. H., and R. L. Ross. 1969. Changes in fawn and doe counts. M.S. Thesis. Colorado mule deer food habits associated with herd State Univ., Fort Collins. 96 p. reduction. J. Wildl. Manage. 33(1):191-195.

Julander, 0. 1937. Utilization of browse by wild- Nichol, A. A. 1936. The experimental feeding of life. N. Amer. Wildl. Conf., Trans. 2:276-287. deer. N. Amer. Wildl. Conf., Trans. 1:403- 410. Keane, C. 1926. The epizootic of foot and mouth disease in California. Calif. Dept. Agr. Spec. Norris, J. J. 1943. Botanical analyses of stomach Publ. 65. 54 p. contents as a method of determining forage consumption. Ecology 24:244-251. Lauckhart, B. 1968. Mule deer management in the state of Washington, W. Assoc. State Game and Overton, W. S. 1971. Estimating the numbers of Fish Comm., Proc. 48: 253-254. animals in wildlife populations. pp. 403- 455. in R. H. Giles, Jr. (ed.). Wildlife Leach, H. R. 1956. Food habits of the Great Basin management techniques. The Wildlife Soc. deer herds of California. Calif. Fish and Wash. D.C. 633 p. Game 42(4) :243-308. Paulik, G. J., and D. S. Robson. 1969. Statistical Leopold, A. 1933. Game management. Charles calculations for change-in-ratio estimates of Scribner's Sons. New YorkILondon. 481 p. population parameters. J. Wildl. Manage. 33(1) :1-27. , W. P. Taylor, R. Bennett, and H. H. Chapman. 1938. Wildlife research - is it a practical Poux, R. J., Jr. 1972. Deer behavior as it affects and necessary basis for management? N. Amer. sex and age ratio counts. M.S. Thesis. Wildl. Conf., Trans. 3:42-55. Virginia Polytechnic Institute and State Univ., Blacksburg. 42 p. Lipscomb, J. F. 1974. A modelling approach to harvest and trend data analysis. W. Assoc. Rasmussen, D. I., and E. R. Doman. 1943. Census State Game and Fish Corn., Proc. 54:56-61. methods and their application in the management of mule deer. N. Amer. Wildl. Conf., Longhurst, W. M., A. S. Leopold, and R. F. Dasmann. Trans. 8:369-379. 1952. A survey of California deer herds, their ranges and management problems. Calif. Sandfort, W. W. 1968. Major factors influencing Dept. Fish and Game Bul. No. 6. 136 p. mule deer population and harvest trends in Colorado since 1962. W. Assoc. State Game , E. 0. Garton, H. F. Heady, and G. E. and Fish Comm., Proc. 48:219-231. Connolly. 1976. The California deer decline and possibilities for restoration. Paper Scooter, G. W. 1966. Sieve mesh size as related presented at the W. Sec. The Wildl. Soc. to volumetric and gravimetric analysis of Fresno, Calif. 38 p. (typewritten). caribou rumen contents. Can. Field-Natur. 80:238-241. Lovaas, A. L. 1958. Mule deer food habits and range use, Little Belt Mountains, Montana. J. Wildl. Seber, G. A. F. 1973. The estimation of animal Manage. 22(3):275-283. abundance and related parameters. Hafner Press. New York. 506 p. McCain, R. 1948. A method for measuring deer range Short, H. L. 1969. Physiology and nutrition of use. N. Amer. Wildl. Conf., Trans. 13:431-441. deer in southern upland forests. pp. 14-18. -in Anonymous. White-tailed deer in the southern forest habitat. Proceedings of a

105 MuZe Deer Manapement Muths symposium. Southern For. Exp. Sta., For. Serv. U.S.D.A.; For. Game Committee S.E. Sec. The Wildl. Soc., and School of For., Stephen F. Austin State Univ. 130 p.

Smith, M. A., K. 0. Fulgham, and J. Malechek. 1975. Diets of wintering mule deer on range grazed heavily by sheep in spring. Paper presented at the 29th Annual Meeting, Soc. for Range Manage. Omaha, Neb. 15 p. (typewritten).

Wallmo, 0. C. 1964. Problems in the use of herd classification data. N. Mex-Ariz Sec. The Wildl. Soc., Proc. 3:6-18.

, R. B. Gill, L. H. Carpenter, and D. W. Reichert. 1973. Accuracy of field estimates of deer food habits. J. Wildl. Manage. 37(4): 556-562.

Mule Deer Management Myths THE POSSIBLE INFLUENCE OF THE MOUNTAIN LION

ON MULE DEER POPULATIONS

Maurice Hornocker Unit Leader

Idaho Cooperative Wildlife Research Unit College of Forestry, Wildlife and Range Sciences University of Idaho Moscow, Idaho 83843

Any discussion of the influence or effect of 2. density of the predator population muntain lion predation on prey populations becomes, of necessity, a discussion of predator-prey relation- 3. characteristics of the prey ships. The reason is obvious - there are practically no data available on lion-prey interactions. Lions 4. density and quality of alternate foods are known to kill deer wherever the two species available for the predator occur together but this merely establishes the fact. The effect of this killing on deer numbers - the' 5. characteristics of the predator really meaningful and important aspect to consider - has scarcely been looked at in an objective way. Each of these variables may exert considerable influence and the effect of any one may depend upon Therefore, today we are a bit limited. We can't changes in another. Considered separately each critically review the literature because there isn't tells little but when considered in combination, any. We will discuss what is known of lions and sound interpretations of the relationships can be their effect on prey from research thus far reported. made. We will talk about the possible influence and effect, or lack of either, of lions on mule deer populations Further, it is important to know the history and the factors that are important in these relation- of interacting populations. Did the species evolve ships. We'll also consider some negative evidence together? Is the relationship an old one or is it concerning the effect of lion predation, the role of recent origin? Is the ecosystem stable or control might play, and needed research. changing? Knowing this, we can make some general statements : I don't intend to launch into a generalized discussion of predation - I don't believe that's 1. The limiting effects of predation tend to necessary here. It will, however, be helpful to out- be reduced and the regulatory (or steady state) line a few of the things basic to predator-prey effects increased where the interacting populations relationships. None of these are my original have a comnnn evolutionary history and they occur thoughts - they are those of numerous authors set in a relatively stable ecosystem. down over a long period of time. 2. Violent predator-prey interactions happen First, what are the possible effects of lion frequently when the interaction is of recent origin predation (or any predation for that matter) on prey or when there has been recent large scale distur- populations? bance of the ecosystem by climatic change, natural holocaust, or by man. 1. The predator can be strongly limiting to the point of reducing the prey to extinction or near So much for the possible effects of predation. extinction. What are its influences?

2. The predator can be regulatory in that it 1. Predation can dampen and protract violent helps keep prey populations within the carrying fluctuations in numbers of prey animals. Damping capacity of their resources, or another way, it con- can act to reduce range damage and serious over- tributes to a steady state in the density of the prey. stocking may be averted until such time as other limiting forces, such as disease, may come into 3. The predator may be neither limiting nor operation. regulating; in other words, the predator is insignificant in the population dynamics of the prey. 2. Predation is also a strong selective force acting to remove prey individuals possessing less Which situation exists between the predator and desirable adaptive characters. its prey depends on different factors. Leopold (1933) classified these into 5 groups: 3. Predators may also act to disperse prey animals and thus cause them to be more evenly dis- 1. density of the prey population tributed on critical range.

The Possible Influence of the Mountain Lion These are the theoretical possible effects and So we really don't know a great deal about the influences of mountain lions on mule deer populations. effect and influence of mountain lions on mule deer What is the real-world evidence for any of these throughout their range. We do know that once prey relationships? This is, or could be, quite important population size is lowered then any depressing at a time when we are experiencing a region-wide factor may have a proportionately greater effect on decline in mule deer populations. that prey population, acting to depress it even further. It appears self-evident to many people Unfortunately we don't have much information. that removal of any depressing influence will result Published information largely, again, deals with the in greater numbers of a prey species. Predators are fact, not the effect. There are several research the most obvious of the depressing factors and projects currently under way, but most of them are naturally attract the most attention. It is here in their early stages. The work by my colleagues and that public and political pressure comes for control. I is the only recent published data on the inter- We know that predator control in some cases will action of lions and mule deer and the effects of that obtain the desired results. We also know that these lion predation. In 10 years of study we found that results often are short-lived and do not solve the lions were not limiting populations of mule deer in long-range problem. Further, the costs are high, a wilderness environment in central Idaho. Their both in an economic and ecologic sense as pointed predation had little effect on ultimate numbers of out by authors from Errington's time on. To these mule deer during this period. The deer population we can now add cultural costs - public relations increased steadily during the first five years, problems. At the same time, some control programs stabilized and remained stable for the remainder of will always be initiated on a basis of political or the project. At the same time the mountain lion emotional expediency only, with no biological or population remained stable because of a fairly ri~id ecological considerations at all. system of territoriality. In this situation under these ecological conditions, lion predation was con- To rectify this situation we need the right sidered beneficial. kind of research. This research needs to address itself, simultaneously and concurrently, to the Harley Shaw (pers. comm.) of the Arizona Game predator population, the prey population, and an and Fish Department has worked with a lion population assessment of the prey habitat. Further, the effects, for several years in Arizona. He has assessed the and not merely the fact, of the predation on the lion kill of domestic stock and has recorded kills of prey population should be the foremost objective. deer. Shaw concludes that lion predation is an Too often in the past, this kind of research has important factor in determining mule deer numbers on gotten side-tracked on predator biology only, on his study area. He believes that deer numbers could the revealing facts of predation (gee whiz, these be increased on his area by removing lions. critters are sure knocking off the deer!), on irrelevant facts of all kinds. These things are These differing results point up the fact that important, but the real issue, the effects of preda- differing ecological units have their own properties tion, are never really learned. At the same time and each must be looked at individually if valid we need to study populations not subjected to interpretations are to be made. This is particularly predation - what happens to deer population levels important with the mountain lion, a reasonably in the absence of predation? This often is long- adaptable predator. term research and so far federal and state agencies havea't been eager to provide funding. But short- We are, of course, specifically concerned about term efforts won't help. the mule deer decline. It is valid to question what role lions play in this decline. Lacking objective If I may, I'd like to quote from some things I data, it may prove useful to examine past histories said about predators and predator control in 1972. of interacting populations. I believe these comments still are valid, and are appropriate for a discussion of our understanding of It is generally accepted that mule deer popula- mountain lion-mule deer interactions: tions peaked in western North America during the period 1940-1970. During this time, mountain lions "We need to know more of the biology were regarded as vermin in all western states, and and ecology of predatory species. We need unregulated killing was encouraged. We could point to know more about self-regulating to the control of lions as the factor responsible for mechanism and how they can be used to high deer numbers, but there is negative evidence to advantage. We need to study and compare, refute this. First, the decline began before unregu- simultaneously, exploited and unexploited lated lion killing ceased. Deer numbers rose populations. We need to recognize the similarly during this period in areas where there was genetic differences between populations no lion control at all - in several of our large of predators and prey that have evolved national parks and some of the larger relatively together and those that have not. We inaccessible wilderness areas. Similar negative need objective assessments of the socio- evidence is available today - the decline of mule economics of predator management. We deer appears uniform throughout the West in areas need research on alternatives to direct where few or no lions occur as well as areas where killing, or reduction control. . . . I they are believed to be numerous. Further, white- believe the application of species biology, tail deer populations are not declining. On the as suggested by Knowlton (1972), is the contrary, they appear to be flourishing, at least in key to future predator management. But the Northwest, both where lions occur and where they first, we must know species biology." do not.

The E'ossib d Influence of the Mountain Lion Summing up:

1. We don't have much objective data concerning lion-mule deer relationships.

2. Lion predation, like any other predation, under certain conditions act to limit prey populations. When a prey population is lowered drastically by whatever factor then any depressing factor gains more importance. In this situation, predator control may help, but usually doesn't solve the problem.

3. Lion predation, like any other predation, normally is ineffective in drastically reducing numbers of prey species when that prey species has suitable habitat.

4. Predator control is a valid wildlife management tool, but if suitable habitat is not available for a prey species, then no amount of predator control will bring about flourishing populations of that prey species.

Mountain lions and mule deer evolved together in the West. Both have survived, often flourished. Their relationship is a simplified straightline one: Habitatjmule deer3lions. Mule deer depend on habitat, lions depend on mule deer. If we improve habitat, we can increase the numbers of deer in the long run; if we decrease lions only, with no habitat change, the results won't be the same.

LITERATURE CITED

Hornocker, M. G. 1972. Predator ecology and management - what now? J. Wildl. Manage. 36:401-404.

Knowlton, F. F. 1972. Preliminary interpretations of coyote population mechanics with some management implications. J. Wildl. Manage. 36: 369-382.

Leopold, A. 1933. Game management. Charles Scribners Sons, New York. 481pp.

109 The Possible Inftuence of the Mountain Lion POTENTIAL INnUENCE OF COYOTES

ON MULE DEER POPULATIONS

Frederick F. Knowlton

U. S. Fish and Wildlife Service Logan, Utah

Abstract

There have been no comprehensive studies of the influence of coyotes upon populations of mule deer. Such a study of a white-tailed deer herd in Texas indicated that coyote predation was a major mortality factor among new-born fawns, accounting for 53 to 75 percent of the fawns born. Coincidental observations, however, showed that other environmental factors were important mediators of the percent of fawns killed by coyotes. Precipitation, as it influenced the quality and quantity of forage available to does. affected the number, size and vigor of fawns born. This was secondarily reflected in the survival rates of fawns and ultimately in the sex ratio of the adult portion of the herd. Exclusion of coyotes from a portion of the herd resulted in increased survival rates of fawns during the first three months after birth, but in subsequent years these gains were offset by increased mortality in later months. Observations from several mule deer and black-tailed deer herds seem consistent with these interpretations. In addition to their impact during the neonatal period, coyotes may kill significant numbers of deer, primarily those under one year old, in mountainous areas where winters are harsh. Malnutrition appears to be a common "facilitator" in many of these cases of predation. In summary, it is apparent that coyotes kill and eat substantial numbers of deer, but the evidence suggests nutritional health of the deer is an important arbitor of many environmental effects, including predation. There are some indications that increased fawn survival can be achieved for brief periods and that deer populations can react more quickly to favorable environmental circumstances in the absence of coyotes. Whether these effects can be translated into a greater abundance, or harvest, of deer remains to be demonstrated.

In assembling and synthesizing the fragments of To maintain some semblance of order in this data that might convey some information about the presentation, I chose to synthesize from a sequence potential impact of coyotes upon mule deer popula- of studies of coyotes and white-tailed deer and then tions, I feel like a novice paleontologist at the seek analogs among the data available for coyotes edge of some prehistoric bone pile. Collecting and and mule deer. examining each "specimen," I am haunted by questions of propriety. Is each really part of the same entity Throughout. I have relied heavily on researches or phenomenon? Are we indeed looking at a common and data provided by others. I am grateful to the process, and do we have the "pieces" arranged appro- individuals who were so willing to share. priately? If not, we may be placing the foot of a Brontosaurus upon a Pterodactyl fitted with the head of a Tvrannosaurus.

111 Potential Influence of Coyotes THE WELDER DEER STORY Some Related Observations

The 7,800-acre Welder Wildlife Refuge on the While analyzing the data from these studies, we Texas Gulf Coast harbors a herd of 1,100 to 1,600 noted several intriguing relationships. The adult deer (1 deer per 5-7 acres). The herd is essentially sex ratio of this unhunted deer population approxi- nonmigratory and the only "hunting" results from col- mated 40 males per 100 females. Furthermore, extrap- lections made to assess biological parameters. The olations of age ratio regressions (Fig. 4) combined deer are grazers, feeding primarily on grasses and with the adult sex composition of the herd suggested herbs year around, (Chamrad and Box 1968). Forage 10.7 male and 17.0 female fawns per 100 adults needed conditions may become restrictive during the cool to survive until January 1 to maintain the herd size winter months as well as the hot, dry summers. and structure. This implies that the sex ratio among fawns surviving to six months of age should be 63 males:100 females. Small samples of fall-trapped General Biologic Parameters fawns revealed a ratio of 55.6 to 100, very close to the calculated figure. Since the fetal sex ratio We determined from the number of ova and fetuses was 117 males per 100 females, twice as great a produced (Table 1) that gross productivity was high mortality rate is suggested for male fawns as com- (K=169 and 163 per 100 does respectively) with pared to female fawns. relatively little mortality through gestation. By January 1, however, the number of fawns was reduced Variations in gross productivity (the number of dppreciably, with mean calculated survival rates ova and/or fetuses produced) appear related to approximately 34 percent (Table 2). Considerable precipation in the year prior to conception (Fig. 5). year to year variation in the ovulation rates, num- This was primarily a function of the frequency of bers of fetuses produced, and survival of fawns twinning rather than changes in the percent of does through the first six months was apparent. that became pregnant. Precipitation patterns also appear to effect changes in the temporal aspects of Two sources of information were used to define the fawn drop, possibly as much as 10 to 14 days. the period when most fawns were lost. On the basis An advance in parturition dates could be expected of the remains of 174 fawns found dead in the field, following years of above normal precipitation and a most died within the first 3 weeks after birth delay in parturitions frequently followed more zeric (Fig. 1). Minimum survival of fawns tagged and conditions. marked shortly after birth, also suggested the majority were lost within the first 21 days of life Net productivity, which is largely a function (Fig. 2). Both data sets suggest the first three of fawn survival rates, appeared to be related to weeks post-partum is critical to fawn survival. the amount of precipitation during gestation (Fig. 6). When precipitation was plentiful, fawn survival was higher than when relatively little Concurrent studies of the feeding patterns of coyotes on the Welder Refuge suggest that deer com- precipitation fell. prised nearly 40 percent of the annual diet of As a result, we were faced with the dilemma of coyotes (Knowlton 1964). There were two periods to explain excessive fawn losses, apparently when deer were particularly important in the diet. trying resulting from coyote predation but whose effect During the summer, coinciding with the fawning period, is mediated by precipitation. Furthermore, we had deer comprised up to 80 percent of the coyote diet (Fig. 3). Another period of heavy use of deer was to account for an apparent "preference" of coyotes noted in winter. for male fawns.

To determine the nature of the relationship Current Interpretations between the large loss of neo-natal fawns and heavv feeding upon fawns by coyotes, Cook et al. (1967) Fruit is an important constituent of the coyote initiated a program of placing radio transmitters on young fawns to facilitate surveillance over an diet (Fig. 7). Following years of below average precipitation, when conception is delayed, parturi- extended period. As reported by White (1966), 81 fawns were tagged with radio transmitters. Fifty tion of deer falls midway between spring and summer eight (72 percent) of these fawns died within the fruiting periods (Fig. 8). When rainfall has been next few months. ~if~~-~h~~~percent apparentlydied abundant, conception and fawning are advanced by 10 as a direct result of predation and an additional 22 or more days. This, coupled with a higher incidence percent had been fed upon by coyotes, but direct of twinning, results in: (a) a major portion of the evidence that coyotes had killed the fawns was ob- fawn drop occurring while the coyotes are "still in the berry patch;" and (b) over-saturati0n with scure. Thus coyotes appear to have been responsible for the death of between 53 and 75 percent of the fawns for a short period with coyotes being unable instrumented fawns. to take full advantage of those available. Both phenomena enhance fawn survival If our analyses had terminated at this point, we would have been professionally negligent not to con- In addition, fetal growth rates are greater clude that the high postnatal loss of fawns was a during wet years than dry (~nowltonand White, in significant factor influencingherd dynamics and that press) resulting in a 20 percent difference in the coyote predation was a primary factor in the low mean birth weight of fawns (Fig. 9). Presumably survival rates observed. Furthermore, to enhance the Larger fawns are healthier and more viable. We also have data indicating that the postnatal growth herd productivity, there seemed little else to sug- rate of male fawns is appreciably greater than their gest but to eliminate the "nasty little varmints." female cohorts (0.45 vs. 0.33 lb./day respectively).

Potential InfZuence of Coyotes At this point it does not seem inappropriate to the circumstances surrounding these observations and speculate that on this area: in assessing the population consequences. 1. The nutritional content of forage, both in quality and quantity, is related to precipitation; The Interstate Deer Herd 2. secondarily, these effects are reflected in the number, size and presumably vigor On the bases of data provided by Salwasser of the fawns at birth; (1976), it seems apparent that the Interstate Deer 3. such nutritional considerations could be Herd has been declining since the 19601s, precipi- expected to intensify during lactation tously in the past 5-7 years (Fig. 13). Gross when the energy and protein demands on productivity has remained high, in the vicinity of the does are maximal; 150 fawns per 100 mature does. Fawn survival, 4. the effects would probably be most pro- especially through summer and fall, has been declin- nounced among the animals with the ing since the mid-1950's (Fig. 14). As depicted in greatest nutritional demands (male fawns) Figure 15, the number of bucks per 100 does has also for growth and with the greatest activity declined (since the sex ratio data was collected schedules (Jackson et al. 1972); and that after the hunting season, the impact of the harvest 5. the foregoing may be compounded by seem- upon the sex ratio should be kept in mind). From ing slight changes in the timing of the an earlier paper (Salwasser 1974) it is apparent parturant process and possibly even the that coyotes in comparable situations feed exten- ability of a doe to meet the nutritional sively on deer during the early postnatal period demands of the fawn. (Fig. 16). On the other hand, Eastman (pers. comm.) offers evidence suggesting there has been no sub- Consequently, p~ecipitationoperating through stantial change in coyote abundance on the summer nutrition, becomes a primary determiner of fawn range of the Interstate Deer Herd (Fig. 17) which survival and ultimately the sex ratio among the might account for the declines noted in survival adult portion of the herd (Fig. 10). At this point and recruitment within the deer herd. it is important to remember that coyote predation is a major instrument of this dynamic process, but apparently precipitation is the programmer. The Steens Mountain Deer Herd

The state of Oregon has been concerned about Effects of Excluding Coyotes declining deer productivity in the Steens Mountain area. As reported by Trainer (1975), 106 new-born The obvious question concerns the possible fawns were captured and equipped with radio trans- effects of eliminating the impact of coyotes from mitters. Fifty-five percent of the fawn mortality the herd. In 1972 a 965-acre predator exclosure was within the first 45 days of life apparently was completed. As reported by John Kie (pers. comm.), related to predation. Coyotes were responsible for fawn survival through 3-months postpartum was sig- 69 percent of it (Table 4). However, since the loss nificantly greater inside the exclosure than outside of fawns to coyotes did not exceed 10 percent, it during 1973; an effect which carried through March hardly seems to be a pivotal event among the herd of the next year. In 1974. the gains apparent in dynamics. early postnatal survival within the predator exclosure (compared to outside) were negated by There is reason for concern, because as Trainer increased mortality in later months (Table 3). points out, the number of fawns per hundred does declined from 131 in June to 86 by September and 29 Fall density of deer inside the exclosure was by March (Table 5). This implies a 78 percent loss nearly double that outside at the start of the study. of fawns before one year of age. To address this Concurrent with the high fawn survival in 1973 and problem, fawns were radio-collared in early winter. 1974, density inside nearly doubled. Subsequently, Subsequently, 50 percent died between January and the population leveled off and/or declined (Fig. 11). April, with coyotes the immediate cause of death In the meantime, deer densities outside the enclosure in 74 percent of the cases. It may be significant, increased but at a substantially lower rate and were however, that two thirds of the carcasses examined slightly lower than inside the exclosure by the revealed advanced states of malnutrition. spring of 1976. With this in mind, it may be pertinent to re- call that Nielson (1975) reported that 28 of 31 HOW DOES THIS APPLY TO MULE DEER? deer found dead during winter were killed by coyotes and that 25 of the 28 were fawns. Since the "state There is little doubt that coyotes eat mule of health" in these instances were not assessed, we deer. Horn (1941) reported about forty percent of can only ponder whether this represents some general the coyote diet on the Los Padres National Forest pattern. was comprised of mule deer (Fig. 12). In Washington, Brigharn (1958) noted an abrupt increase (to over 50 percent) of deer fawn in the coyote diet coincident Enclosures and Exclosures with the fawning period. On the basis of tooth punctures and subcutaneous hemmorhages, Nielsen To my knowledge, there have been two "fencing (1976) reported that 28 of 31 deer found dead near experiments" which provided some information with Hardware Ranch in Utah had been killed by coyotes. regard to the impact of predators on mule deer There are problems, however, in trying to reconstruct populations. The first involved the inadvertent

113 Potential InfZuence of Coyotes Table 1. Gross productivity per 100 does among Table 4. Mortalities of mule deer fawns on Steens white-tailed deer on the Welder Wildlife Mountain, Oregon (from Trainer, 1975). Refuge (from White, 1966).

% of % of Number of Number of -Number - total precedin): -Year -n corpora lutea fetuses Radio-instrumented 106 -- -- 1961 -- --- 165 June-July mortality 29 27 27 1962 33 167 164 Predation caused 16 15 55 1963 46 150 143 Coyote induced 11 10 69 1964 20 160 150 1965 30 197 187 1966 -15 -187 -173 Average 169 163

Table 5. Mule deer fawn mortality based on age ratios from Steens Mountain, Oregon Table 2. Net productivity per 100 does among white- (after Trainer 1975). tailed deer on the Welder Wildlife Refuge (from White, 1966). Fawns per X mortality % mortality -Month 100 does from birth in interval Number fawns fawn survival % June 131 Year (January 1) (through 7 months) -- - September 86 34 1961 51 41 December 54 59 1962 26 21 March 29 78 1963 13 13 1964 48 40 1965 72 54 1966 -50 -38 Average 42 34

Table 6. Mule deer fawns per 100 does (January) inside and outside predator exclosure on Three Bar Ranch, Arizona (after LeCount Table 3. Fawns per 100 does inside and outside 1974,1975). predator exclosure on Welder Wildlife Refuge (from Kie, pers. comm.). Inside Rest of Year Exclosure three bar Predator Outside - Year Exclosure Exclosure 1971 22 26 - 1972 118 42 1972 (Sept.) 45 45 1973 82 70 1973 (Sept.) 66 28 1974 111 59 1974 (Mar.) 47 31 (Sept.) 63 4 7 -3 (Dec. ) 51 46 1975 (Mar. ) 45 43 ------Age at death (weeks) Age class Figure 1. Age at death of 174 fawns found dead on the Figure 4. Age ratio regressions for adult male and Welder Wltdlife Refuge (from White, 1966). female white-tailed deer on Welder Nild- life Refuge (after Knowlton, 1964).

20 40 60 80 100 120 140 160 Days post partum

Figure 2. Minimum longevity of 128 tagged deer fawns Figure 5. Comparison of gross productivity of white- on Welder Wildlife Refuge (from Xnowlton, tailed deer on Welder Wildlife Refuge and 2964). precipitation in the year preceding conception (after White, 1966).

Yigure 3. Percent of the coyote diet comprised of Figure 6. Comparison of fawn survival to 6 months deer (after Knowlton, 1964). of age with precipitation during gestation (a£ter White, 1966). Figure 7. Percent of coyote diet on Welder Wildlife Refuge comprised of fruit (after Knowlton, 1964).

Figure 10. Comparison of annual precipitation, fawn survival, and sex composition within the adult portion of the Welder white-tail Figure 8. Chronology of fruit and deer in the coyote herd (after White, 1966). diet during a "dry" year on the Welder IJildlife Refuge (after Knowlton, 1964).

Figure 11. Deer densities within and outside the predator exclosure on the Welder Refuge (from Kie pers. comm.).

+ 40 .- n "- 20 P) 2 a FMAMJJAS

Figure 9. Fetal growth rates of white-tailed deer Figure 12. Percent frequency of mule deer in the during periods of high and low precipita- coyote diet on Los Padres National Forest tion (from Knowlton and White in press). (from Horn, 1941). Figure 13. Relative abundance of mule deer in the Interstate area, 1949-1973 (from Salwasser, 1976). 1-15 16-30 1-15 16-34 1-15 16-31 JUNE J U LY AUGUST Figure 16. Percent occurrence of mule deer fawn in the coyote diet in the North Kings deer herd (from Salwasser, 1974).

Figure 14. Estimated fawn survival rates for the Interstate mule deer herd between 1954 and 1974 (from Salwasser, 1976). Figure 17. Index of coyote abundance on the summer range of the Interstate deer herd (from Eastman pers. comm.)

Figure 15. Post-harvest sex ratio in the Interstate deer herd 1950 through 1974 (from Salwasser, 1976). enclosure of one coyote with a group of mule deer in Literature Cited Central Utah. As reported by Robinette and Olson (19441, productivity was 49 percent lower in the Brigham, J. H. 1958. Early mortality in black- pasture with the coyote as compared to an adjacent tailed deer in western Washington. M.S. pasture with no coyotes. Thesis. Wash. State Univ., Pullman. 47 pp.

A predator exclosure was built on the 3-Bar Chamrad, A. D., and T. W. Box. 1968. Food habits Ranch in Arizona in 1971. According to LeCount of white-tailed deer in South Texas. J. Range (1974, 1975), net productivity within the exclosures Mgmt. 21(3):158-164. (measured in January) averaged nearly twice that observed on the rest of the 3-Bar Ranch (Table 6). Cook, R. S., M. White, D. 0. Trainer and W. C. The number of deer within the enclosure was rela- Glazener. 1967. Radio-telemetry for fawn tively small and substantial fluctuations in produc- mortality studies. Bull. Wildl. Dis. Assoc. tivity were evident. It is also interesting that 3(4) :160-165. the lowest productivity outside the enclosure was identified with a drought, and the highest produc- Horn, E. E. 1941. Some coyote-wildlife relation- tivity with a year of abundant precipitation. ships. Trans. N. Amer. Wildl. Conf. 6:238-287 (In Young, S. P. and H. H. T. Jackson. 1951. The Clever Coyote. The Stackpole Co., SUMMARY Harrisburg and Wildl. Inst., Wash. D.C. 411 PP.) At the outset, it is essential to recognize that coyotes eat and kill deer. It is equally important Jackson, R. M., M. White and F. F. Knowlton. 1972. to recognize that other environmental factors may be Activity patterns of young white-tailed deer important mediators of the impact predators may have fawns in South Texas. Ecology 53(2):262-270. on deer populations. In some instances, predation may be symptomatic of other environmental deficien- Knowlton, F. F. 1964. Aspects of coyote predation cies. Certain similarities between studies on mule in South Texas with special reference to white- deer and the Welder whitetail herd are inescapable. tailed deer. Ph.D. Dissert. Purdue Univer., Lafayette. 189 pp. Evidence at this point suggests the nutritional status of the deer may be a key to a host of envi- Knowlton, F. F. and M. White. In press. Weight ronmental effects; effects which frequently syn- patterns of wild white-tailed deer in South ergize in natural environments. Within the Welder Texas. J. Wildl. Mgmt. herd, the number, size, health and survival of fawns appears closely linked to the quality of food avail- Le Count, A. L. 1974. Causes of fawn mortality. able to the doe. Some parallels seem appropriate Perform. Report., Proj. No. W-78-R-l8,WP2,Jll, among mule deer. Additionally, nutritional health Ariz. 6 pp. (multil.). of mule deer in winter may contribute to the impact of coyotes at that season. While it may be rela- Le Count, A. L. 1975. Causes of fawn mortality. tively easy to assess the "nutritional state" of Perform. Report., Proj. No. W-78-R-l9,WPZ,Jll, the winter range, we may not yet be prepared to Ariz. 3 pp. (multil.). define, much less evaluate, the late gestation and fawning ranges which appear so vital to the vigor Nielson, D. B. 1975. Coyotes and deer. Utah Sci. and survival of fawns. 38 (3) :87-90.

The degree to which deer abundance can be Robinette, W. L. and 0. A. Olson. 1944. Studies of influenced by removal of coyotes remains to be de- the productivity of mule deer in central Utah. monstrated. Research is currently under way. Some Trans N. Amer. Wildl. Conf. 9:156-161. evidence is available suggesting short term effects of increased fawn survival for brief periods can be Salwasser, H. 1974. Coyote scats as an indicator achieved through elimination of coyotes. There is of time of fawn mortality in the North Kings also evidence that deer populations may be able to deer herd. Calif. Fish and Game 60(2):84-87. react more quickly to favorable environmental circumstances in the absence of coyotes. Salwasser, H. 1976. Status and trends of the Devil's Garden Interstate Mule Deer Herd, 1975. On the other hand, I am reluctant to suggest Interstate Wildl. Study Newsletter 4:17-31. there is currently any evidence that we can enhance deer abundance over extensive periods of time solely Trainer, C. 1975. Direct causes of mortality in through the removal of coyotes. In short, my final, mule deer fawns during summer and winter definitive and irrevocable judgment with regard to periods on Steens Mountain, Oregon ...A Progress the possible influence of coyotes on mule deer Report. Proc. of Ann. Conf. of Western Assoc. populations is.. ."Maybe!" of State Game and Fish Commiss. 55:163-170.

White, M. 1966. Population ecology of some whitetail deer in South Texas. Ph.D. Dissert., Purdue Univ., Lafayette. 215 pp.

Potential Influence of Coyotes MULE DEER DISEASE PROBLEMS

Annie K. Prestwood 1 1 Victor F. Nettles

Charles P. Hibler 2 1 Frank A. Hayes

'southeastern Cooperative Wildlife Disease Study CcQlege of Veterinary Medicine University of Georgia Athens, Georgia 30602

L.Wild Animal Disease Center College of Veterinary Medicine and Biomedical Sciences Colorado State University Fort Collins, Colorado 80523

Abstract

Viral, bacterial, and parasitic diseases are considered important potential causes of mortality among mule deer populations. Various aspects on the pathologic manifestations and epizootiology are presented for the hemorrhagic disease complex (bluetongue and epizootic hemorrhagic disease), necrobacillosis, gastrointestinal trichostrongylosis and lungworm disease.

The importance of diseases affecting human and and malignant catarrhal fever (MCF) respectively, are livestock health long has been recognized and is considered threats to mule deer populations. evidenced in the United States today by enormous expenditures by the Departments of Health, Education, Table 1. Fundamental Causes of Morbidity and and Welfare and Agriculture as well as by states and Mortality Among Wild Animal Populations private philanthropic agencies. In contrast, diseases of free-living wild animals largely have been ignored, Anomalies and only recently have+diseasesof wildlife received Stress attention. As a result, a relative dearth of Trauma knowledge exists on diseases affecting wild popula- Suffocation tions. This fact was all too evident when searching Neoplasie the literature for accounts of diseases affecting Toxins mule deer (Odocoileus hemionus). As a result, this Nutritional Deficiencies presentation is largely speculative based on infor- Viruses and Rickettsia mation derived from the literature and extrapolated Bacteria from our experiences with diseases of white-tailed Fungi deer (9.virginianus) . Parasites Senility In 1969 we presented a list of 12 fundamental causes of morbidity and mortality among wildlife populations (Table 1) and described a process of The so-called "hemorrhagic complex" consists of elimination whereby potential causes of death could two viral diseases, bluetongue (BT) and epizootic be narrowed from 12 to 3 or 4 (Hayes and Prestwood hemorrhagic disease (EHD), which cannot be distin- 1969). When considering diseases potentially capable guished clinically or by gross or microscopic lesions. of causing a widespread decline of mule deer popula- Hemorrhagic disease is characterized by hemorrhage tions, we applied this method of elimination. As a and vascular thrombosis with resultant necrosis of result, a list of diseases of potential importance to affected tissues. mule deer populations was compiled (Table 2). Bluetongue is enzootic throughout much of the Viral Diseases - Three viral agents producing United States. In 1974 BT virus was recovered from two clinical syndromes, hemorrhagic disease (HD)

119 Mule Deer Disease Pro~Zems also in feral cattle in contact with whitetails where 'Table 2. Diseases of Potential Importance for Mule HD was not recognized (Thomas and Prestwood 1976). Deer Populations. Although we were unable to locate published A. Viral Diseases reports of clinical BT in mule deer, one of the 1. Hemorrhagic Disease Complex authors (CPH) has recovered BT virus from captive a. Bluetongue mule deer which were dying of an acute hemorrhagic b. Epizootic hemorrhagic disease disease syndrome. Mule deer reportedly are rela- B. Bacterial Disease tively resistant to infection with EHD virus, and in 1. Necrobacillosis outbreaks of EHD, carcasses of white-tailed deer C. Parasitic Diseases outnumber those of mule deer 23 to 1. Sero-positive 1. Gastrointestinal Trichostrongyles reactors to EHD virus were prevalent among mule deer a. Haemonchus contortus following an outbreak of EHD in deer of North Dakota 2. Lungworms during 1970 and 1971, suggesting that they were a. Dictyocaulus viviparus similarly exposed to this viral agent (Hoff et al. b. Parelaphostrongylus odocoilei 1973). The effects of BT and EHD viruses, particu- c. Parelaphostrongylus tenuis larly latent infections, in mule deer require further study before these diseases can be properly assessed for mule deer populations. herds of cattle in Colorado and Oregon and from sheep flocks in California, Idaho, New Mexico, Oregon, and Acute and chronic hemorrhagic disease in white- Texas (Shoenfeld et al. 1974). In addition, tailed deer have been delineated (Prestwood et al. BT-positive modified complement-fixation test reactors 1974). The primary pathogenic mechanism appears to were detected in Arizona, Arkansas, California, be disseminated intravascular coagulation (Tsai and Colorado, Florida, Idaho, Indiana, Kansas, Kentucky, Karstad 1973). The acute disease is characterized Louisiana, Michigan, Missouri, Montana, Nebraska, by extensive hemorrhage and thrombosis. In chronic Nevada, New Mexico, New York, North Carolina, North hemorrhagic disease, pathologic lesions are quite Dakota, Ohio, Oklahoma, Oregon, South Dakota, Texas, variable but reflect sequalae of vascular damage. Utah, Virginia, Washington, Wisconsin, and Wyoming These changes are most pronounced in the digestive (Shoenfeld et al. ibid). This agent appears enzootic tract but also may involve the coronary band and in the south Atlantic and Gulf coastal plain of the sensitive laminae of the hooves. Necrotic stomatitis, southeastern United States (Thomas and Prestwood 1976) rumenitis, and omasitis often occur, and ulceration and Texas (Hoff et al. 1974; Marburger et al. 1970). of the rwnenal pillars may be pronounced. Laminitis The virus of EHD similarly is widespread throughout may be sufficiently severe to cause sloughing of the much of the United States and Canada. Sero-positive hooves. Fawns infected while nursing frequently EHD plaque reduction neutralization test reactors exhibit severe destruction of the rumenal lining. were found widely distributed among white-tailed deer These animals may survive initial infection only to populations of the southeastern United States prior succumb after weaning when the diet shifts to rough- to the 1971 epizootic of HD (Thomas and Prestwood age. Starvation or predation are the usual fate for 1976). Hemorrhagic disease has been seen annually in these animals. In adult survivors, secondary this region since that time. infections of the digestive tract and feet are usual sequalae. These lesions may be manifest as necrotic During the 1975 epizootic of HD in New Jersey, stomatitis, ulcerative rumenitis, or pyogenic only one virus--EHD--was isolated (Anon. 1976). This infections of the feet. Involvement of the feet was in contrast to the 1971 outbreak in the Southeast often is observed in hunter-killed deer. Infection where both BT and EHD viruses were involved (Prestwood of does during the early stages of gestation may et al. 1974). Similarly only EHD virus was isolated result in absorption of fetuses or abortion (Thomas from deer dying of HD in North Dakota during 1971, and Trainer 1970) and possibly stillbirths or however, sero-positive reactors to BT were found among malformed fetuses as observed with domestic livestock. hunter-killed deer following that mortality (Hoff The long term effect of BT on productivity of white- et al. 1973). tailed or mule deer populations has yet to be explored. The virus of BT disease is transmitted by biting aidges (Culicoides). Recent unpublished evidence Presumptive diagnosis of HD can be made on the suggests that EHD virus also is transmitted by this basis of gross and microscopic lesions, however vector. Hemorrhagic disease is seasonal and usually isolation and characterization constitute the only occurs in the late summer and early fall when flies means for distinguishing the viruses of BT and EHD. are abundant. Epizootics characteristically cease with the first frost. Malignant catarrhal fever (MCF) is a viral disease of domestic and wild ruminants characterized Sheep are severely affected by BTV, and vaccina- by catarrhal, mucopurulent, or necrotizing inflam- tion is practiced by some sheep herders. Only mation of the respiratory and digestive tracts and occasionally is BT manifest clinically in cattle, eyes. The disease is worldwide in distribution, and however, these animals may harbor the virus most outbreaks in North America are sporadic in inapparently for extended periods. This finding led occurrence. In the United States, MCF has been to the hypothesis that cattle are reservoirs for BT diagnosed in axis (Axis axis) and white-tailed deer virus (Bowne 1973). in southern Texas (Clark et al. 1970; Clark and McConnell 1972), in white-tailed deer of New Jersey The role of cattle in the epizootiology of EHD and Connecticut (Wyand et al. 1971), and in greater presently is unknown, however, antibodies to EHD have kudu (Tragelaphus strepsiceros) in Missouri (Bolver been detected among sentinel cattle placed in contact and Kurka 1974). Additionally, MCF has been with white-tailed deer during an outbreak of HD and recognized in American bison (Bison bison) and

Mule Deer Disease Problems captive mule deer in Colorado (Pierson et al. 1974). Diagnosis of necrobacillosis is based on One of the authors (CPH) has experimentally trans- isolation of F. necrophorum from affected tissues. mitted MCF to mule deer. Among cattle the disease It should be mentioned that the lesions of chronic appears sporadically in sheep-raising areas of the hemorrhagic disease with secondary bacterial infec- midwest and west. tion in white-tailed deer are markedly similar to those described for necrobacillosis in mule deer. The mode of transmission of MCF is unknown, The role of BT virus in producing a portal of entry however the recent discovery of MCF virus in nasal for F. necrophorum should be a fruitful area for secretions of blue wildebeest (Connochaetes taurinus) future study. led to the hypothesis that nasal shedding of MCF virus may be a mechanism for transmission of virus among Parasitic Diseases - Two major groups of wildebeest and from wildebeest to cattle (Rweyemamu nematodes, trichostrongyles and lungworms, are of et al. 1974). In Africa, wildebeest are natural potential significance in portions of the mule deer's reservoirs of MCF virus. Sheep are considered natural range. reservoirs elsewhere. The gastrointestinal trichostrongyles infecting In cattle, peracute, alimentary, head and eye, mule deer comprise several genera (Walker and and mild forms of MCF have been described. Among deer, Becklund 1970), and in areas where climatic conditions the disease was best described for axis deer (Clark are conducive to parasitism, Haemonchus contortus et al. 1970). Axis deer with MCF were lethargic, s.l., the large stomach worm, is of particular emaciated, weak, ataxic, and apparently blind. importance. This helminth may cause considerable Neurologic disturbance was present in some animals. blood loss among fawns. The occurrence of H. Gross lesions consisted of corneal opacity, areas of contortus is worldwide, however it is locally more alopecia encrusted with thick, dried exudate, greatly common in some areas than others even in humid enlarged lymph nodes and enlarged arteries. Gross environments. In the southeastern United States, for lesions in white-tailed deer ranged from none to example, H. contortus is more prevalent and has a hemothorax causing sudden death. Diagnosis of MCF higher intensity of infection in deer of the lower is based on histologic lesions consisting of coastal plain than in more upland terrain (Prestwood fibrinoid necrotizing vasculitis which are considered et al. 1972). The host range for H. contortus pathognomonic for this disease (Jubb and Kennedy 1970). includes cattle, sheep, goats, and nwnerous wild Eye lesions and neurologic signs, when present, serve ruminants. Although species of llaemonchus infecting to distinguish MCF from BT and EHD. cattle and sheep have been separated, the genus appears to be in a state of evolutionary flux. Das Bacterial Diseases - Only one bacterial disease, and Whitlock (1960) consider g. contortus to be necrobacillosis, is considered a serious threat to actively evolving and that the species contains a mule deer populations. The disease is caused bv number of well defined demes, each adapted to a ~usobacterium (=Spherophorus) necrophorum. particular host-microclimate interaction. Considerable controversy exists on whether F. necrophorum acts as a primary or secondary Tnvader. The principal effects of Haemonchus are due to Jubb and Kennedy (1970) state, "In no instance has it anemia, which in heavily infected animals is yet been credited with the role of primarily pene- accompanied by edema, emaciation, and generalized trating pathogen." Rosen (1970) considered F. digestive disturbances. Both 4th stage larvae and necrophorum a probable opportunist awaiting an adult 2. contortus cause blood loss. At necropsy abrasion or injury to serve as an avenue for submandibular edema ("bottle jawt'), enlarged lymph invasion. nodes, and thin, watery blood may be obvious. The lining of the stomach may be swollen, and have Necrobacillosis has been diagnosed in a variety petechial hemorrhages with shallow ulcerations. of wild cervidae, primarily in the western United Young deer usually are more heavily infected than States. It has been considered a major cause of the adults (Prestwood and Kellogg 1971). mortality among mule deer in California (Rosen et al. 1951; Rosen 1970) and among wapiti (Cervus canadensis) Conditions that predispose animals to H. of Wyoming (Murie et al. 1944 cited in Rosen 1951). contortus also are conducive to heavy infections Periodic outbreaks of necrobacillosis occur in many with other abomasal or intestinal trichostrongyles, species of domestic livestock. Among sheep and cattle, and pure infections with a single species of nema- frequently necrobacillosis is encountered when the tode are uncommon. Similarly, nutritional status of environment is dark, dirty, damp, and overcrowded. the animal is of paramount importance since poor Epizootics in California deer have occurred when nutrition and parasitism often occur concomitantly. animals have been overly concentrated near muddy water Although one helminth, e.g. H. contortus, may be the holes due to drought (Rosen et al. 1951). When the actual cause of death in deer, overcrowding, food environment is sufficiently seeded with F. necrophorum shortage, and competition by other ruminants or organisms the disease apparently becomes contagious swine are important contributing factors leading to (Jubb and Kennedy 1970). death from gastrointestinal parasitism.

Lesions produced by F. necrophorum in mule deer Two types of lungworms infect mule deer, viz. are variable depending onthe site of infection. A 1. those whose adult stage is found in the lung foot rot syndrome often is present,which is charac- (Dictyocaulus viviparus) and 2. those whose adult terized by necrosis of the interdigital tissue, stage occurs in sites remote from the lungs but inflammation of the coronary band and sensitive whose eggs and larvae pass through the lungs to the laminae, and extension into the proximal joint above external environment (Parelaphostrongylus spp.). the hoof (Rosen et al. 1951). Necrotic stomatitis, ulcerative rumenitis and abscesses in other organs The large lungworm, Dictyocaulus viviparus, is also may occur. located in the bronchi and bronchioles of mule deer

121 hZe Deer visease Problems where it produces a parasitic bronchitis. Dictyocaulus the cranial meninges of white-tailed deer. The life is worldwide in distribution, with increased prevalence cycle is indirect, and similar to that of P. odocoilei. in cool, moist areas. Like other trichostrongyles, D. Detailed studies by Anderson (1963; 1965) and Anderson viviparus has a direct life cycle. Cattle and various and Strelive (1967) have shown that after ingestion, wild ruminants serve as definitive hosts for large infective larvae penetrate the abomasal wall and lungworms, however, recent work has shown that travel to the spinal cord of white-tailed deer. Dictyocaulus of wild ruminant origin has low infectiv- Development occurs in the dorsal horns of gray matter ity in cattle suggesting that there may be host for 30-40 days, after which worms move to the subdural specific strains of this helminth (Presidente et al. space. First-stage larvae appear in the feces 90 days 1972, 1973; Gupta and Gibbs 1971). or more post-infection.

In the southeastern United States, about 30 Neurologic signs are rare in white-tailed deer, percent of white-tailed deer harbor D. viviparus. however, neurologic disturbances leading to paralysis Infection is most prevalent and intense in young and death have been observed in unusual hosts, erg. animals, particularly buck fawns. Dictycauliasis is domestic sheep, moose (Alces alces), wapiti, caribou seasonal in occurrence; the prevalence and intensity (Rangifer tarandus terranovae) and reindeer (R. t. of infection are higher in late summer and early fall. tarandus) (Anderson 1970). A mule deer fawn was The parasite is least common during the winter experimentally infected with 5. tenuis, and a fatal (Prestwood et al. 1971). Outbreaks of D. viviparus paralysis ensued (Anderson et al. 1966). Black- pneumonia have been recorded in captive black-tailed tailed deer translocated into Tennessee from Oregon deer in Oregon (Presidente et al. 1973). also were afflicted with fatal neurologic disease caused by P. tenuis, which apparently has been a At necropsy, lesions caused by D. viviparus may primary li$iting factor for establishing black-tailed be mild to severe. Extensive pneumonia may be present, deer in Tennessee. Experimental infection of a and there may be numerous lungworms and exudate in the hybrid deer (2. h. columbianus x 2. virginianus) bronchi. Pleuritis and interlobular thickening may be resulted in fatal paralysis 52 days post-infection obvious. Occasionally edema and enlarged lymph nodes (SCWDS, unpublished). and lymph vessels are detected. Lung damage may be particularly severe when first-stage larvae of It appears that the encroachment of white-tailed Parelaphostrong* sp. also are present (Prestwood deer onto the range of mule deer is a definite threat et al. 1971). because of the likelihood of exposing mule deer populations to E. tenuis. Mule deer may be infected by at least two species of Parelaphostrongylus, viz. P. odocoilei and P. tenuis. Although each of the aforementioned diseases has Parelaphostrongylus odocoileiis located adjacent to been considered a specific potential mortality factor or within small vessels in the musculature of the hind- for mule deer populations, we should emphasize that body of black-tailed and mule deer. It also has been seldom does one entity alone cause significant found within small vessels in the lungs. This helminth mortality of a wild population. Rather, multiple has been reported only from deer of California factors usually are involved, and the specific (Hobmaier and Hobmaier 1934; Brunetti 1969) . Recently, disease is a product of complex interactions between however, similar protostrongylid larvae were found in the animal and its environment. Judging from the the feces of mule deer from Western Canada (Samuel and apparent lack of information on diseases of mule deer, Iiolmes 1'171). One of the authors (CPH) has seen we respectfully suggest that concerned game and fish protostrongylid larvae in feces of southwestern mule agencies place more emphasis on investigating dis- deer. eases of mule deer. These investigations should include specific information on causes of "die-offs" The life cycle of P. odocoilei is indirect. Eggs and probably more importantly, should consider what are deposited in the circulation and arrive as emboli potential mortality factors are present within in the lungs where hatching occurs. First-stage apparently healthy populations. Only until we have larvae ascend the bronchial passageways and trachea, a basic understanding of the interactions between are swallowed and eliminated with the feces. Various the disease agent, the animal, and the environment terrestrial snails and slugs (Helix aspersa, can the causes of the mule deer decline in the west Agriolimax agrestis, A. compestris, Planorbis sp.) be ascertained. serve as intermediate-hosts . Deer become infected after ingesting snails containing infective P. odocoilei larvae. The pre-patent period is approximately 2 1/2 months. Acknowledgments: This study was supported in part by funds administered and coordinated under the Federal Adult P. odocoilei produce small hemorrhages in Aid in Wildlife Restoration Act (50 Stat. 917) and the muscula~ure. Extensive tissue damage caused by through Contract No. 14-16-0008-2028, Fish and eggs and larvae of P. odocoilei has been seen histo- Wildlife Service, U.S. Department of the Interior. logically in the lungs and lymph nodes and has been considered a cause of death among California deer (Brunctti 1969). LITERATURE CITED

Mule deer have been experimentally infected with Anderson, R. C. 1963. The incidence, development, the meningeal worm, Parelaphostrongylus tenuis and experimental transmission of Pneumostrongylus (Anderson et al. 1966). This helminth is widely tenuis Dougherty (Metastrongyloidea: distributed throughout the range of its usual host, Protostronevlidae)", of the meninges of the white- the white-tailed deer, and has been recorded as far tailed deer docbi bile us virginianus borealis) in west as Oklahoma and Minnesota. Adult helminths are Ontario. Can. J. Zool. 41: 775-792 + figs. located in the subdural space and venous sinuses of

Mule deer Disease Problems 122 . 1965. The development of Pneumostrongylus Jubb, K. V. F. and P. C. Kennedy. 1970. Pathology tenuis in the central nervous system of white- of Domestic Animals. Vol. 2, 2nd ed., Academic tailed deer. Path. Vet. 2: 360-379. Press, New York. 697pp. . 1970. Lungworms. p. 81-126. In Davis, Marburger, R. G., R. M. Robinson, J. W. Thomas, and J. W. and R. C. Anderson editors. Parasitic K. A. Clark. 1970. Management implications of Diseases of Wild Mammals. Iowa State Univ. Press, disease of big game animals in Texas. Proc. Ames, Iowa. 364pp. Southeast Assn. Game and Fish Comm. 24: 46-50. and Strelive. 1967. The penetration of Pierson, R. E., J. Storz, A. E. Chesney, and D. Thake. Pneumostrongylus tenuis into the tissues of white- 1974. Experimental transmission of malignant tailed deer. Can. J. Zool. 45: 285-289. catarrhal fever. Am. J. Vet. Res. 35: 523-525. , M. W. Lankester, and U. R. Strelive. Presidente, P. J. A. and S. E. Knapp. 1973. 1966. Further experimental studies of Susceptibility of cattle to an isolate of Pneumostrongylus tenuis in cervids. Can. J. 7001. Dictyocaulus viviparus from black-tailed deer. 44: 851-861. J. Wildl. Dis. 9: 41-43. Anonymous. 1976. Foreign Animal Disease Report, , and R. E. Dean. 1973. January 1976. Emergency Programs, Veterinary Treatment and control of Dictyocaulus viviparus Services, APHIS, USDA, Washington, D. C. 12pp. in captive black-tailed deer. J. Wildl. Dis. 9: Boever, W. J. and B. Kurka. 1974. Malignant catarrhal fever in greater kudus. J. Am. Vet. Med. , D. E. Worley, and J. E. Catlin. 1972. Assn. 165: 817-819. Cross-transmission experiments with Dictyocaulus viviparus isolates from Rocky Mountain elk and Bowne, J. G. 1973. Is bluetongue an important cattle. J. Wildl. Dis. 8: 57-62. disease in cattle. J. Am. Vet. Med. Assn. 163: 911-914. Prestwood, A. K. and F. E. Kellogg. 1971. Naturally occurring haemonchosis in a white-tailed deer. J. Brunetti, 0. A. 1969. Redescription of Parelapho- Wildl. Dis. 7: 1.33-134. strongylus (Boev and Schuls, 1950) in California deer, with studies on its life history and , J. F. Smith, and J. Brown. 1971. pathology. Calif. Fish and Game 55: 307-316. Lungworms in white-tailed deer of the southeastern United States. J. Wildl. Dis. 7: 149-154. Clark, K. A., R. M. Robinson, L. L. Weishuhn, and S. McConnell. 1972. Further observations on , F. A. Hayes, J. H. Eve, and J. F. Smith. malignant catarrhal fever in Texas deer. J. 1973. Abomasal helminths of white-tailed deer in Wildl. Dis. 8: 72-74. southeastern United States, Texas, and the Virgin Islands. J. Am. Vet. Med. Assn. 163: 556-561. R. G. Marburger, L. P. Jones, and J. H. Orchard. 1970. Malignant catarrhal , T. P. Kistner, F. E. Kellogg, and fever in Texas cervids. J. Wildl. Dis. 5: 376-383.. F. A. Hayes. 1974. The 1971 outbreak of hemorrhagic disease among white-tailed deer of Das, K. M. and J. H. Whitlock. 1900. Subspeciation the southeastern United States. J. Wildl. Dis. in Haemonchus contortus (Rudolphi, 1803), Nematoda, 10: 217-224. Trichostrongyloidea. Cornell Vet. 50: 182-197. Rosen, M. N. 1970. NecrobacillosiS.. p. 286-292. Gupta, R. P. and H. C. Gibbs. 1971. Infectivity of -In Davis, J. W., L. H. Karstad, and D. 0. Trainer -D. viviparus (moose strain) to calves. Can. Vet. editors. Infectious Diseases of Wild Mammals. J. 56: 56. Iowa State Univ. Press, Ames, Iowa. 421pp. Hayes, F. A. and A. K. Prestwood. 1969. Some , 0. A. Brunetti, A. I. Bischoff, and considerations for diseases and parasites of white- J. A. Azevedo, Jr. 1951. An epizootic of foot tailed deer in the southeastern United States. rot in California deer. North Am. Wildl. Conf. Proc. Symposium White-tailed Deer in the Southern 16: 164-177. Forest Habitat. Nacogdoches, Texas. 32-36. Rweyemamu, M. M., L. Karstad, E. Z. Mushi, J. C. Hobmaier, A. and M. Hobmaier. 1934. Elaphostrongylus Otema, D. M. Jessett, L. Rome, S. Drevema, and odocoilei n. sp., a new lungworm in blacktail deer J. G. Grootenhuis. 1974. Malignant catarrhal (Odocoileus columbianus). Description and life fever virus in nasal secretions of wildebeest: history. Proc. Soc. Expl. Biol. and Med. 31: a probable mechanism for virus transmission. 509-514. J. Wildl. Dis. 10: 478-487. Hoff, G. L., S. H. Richards, and D. 0. Trainer. 1973. Samuel, W. M. and J. C. Holmes. 1974. Search for Epizootic of hemorrhagic disease in North Dakota elaphostrongyline parasites in cervids from deer. J. Wildl. Mgt. 37: 331-335. Alberta. Can. J. Zool. 52: 401-403. , D. 0. Trainer, and M. M. Jochim. 1974. Schoenfeld, F. J. et al. 1974. Report of the Bluetongue virus and white-tailed deer in an committee of diseases of sheep and goats 1974. enzootic area of Texas. J. Wildl. Dis. 10: Report U.S. Animal Health Assn. 78: 393-396. 158-163. Thomas, F. C. and A. K. Prestwood. 1976. Plaque neutralization reduction test reactors to bluetongue virus and EHD virus in the southeastern United States. In Page, L. editor. Wildlife Diseases. Plenum ~uixishingCorp., New York. In Press. , and D. 0. Trainer. 1970. Bluetongue virus (1) in pregnant white-tailed deer, (2) a plague reduction neutralization test. J. Wildl. Dis. 6: 384-388. Tsai, K. and L. Karstad. 1973. The pathogenesis of epizootic hemorrhagic disease of deer. Am. J. Pathol. 70: 379-400. Walker, M. L. and W. W. Becklund. 1970. Checklist

of.- the internal and external parasites of deer, Odocoileus hemionus and 2. virginianus, in the United States and Canada. Special Publication No. 1. Index Catalogue of ~edicaland Veterinary Zoology. USDA, Washington, D. C. 45pp. Wyand, D. S., C. F. Helmboldt, and S. W. Nielsen. 1971. Malignant catarrhal fever in white-tailed deer. J. Am. Vet. Med. Assn. 159: 605-610.

Mule Deer Disease Problems MULE DEER MORTALITY FROM VARIOUS CAUSES

W. Leslie Robinette Retired Wildlife Research Biologist U.S. Fish & Wildlife Service Present Address: 488 So. Alkire St. Lakewood, Colo. 80228

Abstract

Evidence is presented that several Great Basin deer herds produced fall fawn crops of 100 or more fawns per 100 does before widespread use of the range. Subsequently, fall fawn crops dropped to only 60 or 70 percent. It is the writer's contention that poorer nutrition caused by range depletion was responsible for the reduction in fawn crops and that this has been a major factor in the general decline in mule deer populations. The solution would seem to lie in even further herd reductions through hunting to a level that will permit range recovery through natural plant succession or artificial revegetation.

I suspect that those responsible for this sym- reduced coyote numbers. The decline was almost posium intended that this paper should cover all certainly associated with an overstocked summer classes of deer mortality not covered by previous range. The most striking evidence for overstocking papers and relate them to the general mule deer de- was the highlining of curlleaf mountain mahogany cline. There is little doubt that vehicles, starva- (Cercocarpus ledifolius) and aspen (Populus tion and poaching, for example, have been or are cur- tremuloides) and the absence of regeneration. rently important mortality factors among some herds Observations have indicated that when this occurs, and in some years. Many deer are killed by vehicles, most of the palatable forbs have likewise been particularly where interstate highways cross migra- depleted. tion routes or winter ranges. Starvation losses are less common now than 2-4 decades ago but still may A decline in fawn crops also occurred on the occur during severe winters, prolonged droughts, or Dixie National Forest in southwestern Utah, but it among inadequately hunted herds. While these clas- took place a few years earlier than in Duck Creek. ses of mortality may be locally important, it is Classifications gave a fawn crop of 101 percent in doubtful that they have been the major causes for 1936; 94 for 1937; but an average of only 65 for the general decline. the 6 years, 1940-45 (Noel 1948). Overstocking was recognized by the U. S. Forest Service and Utah I should like to take this opportunity to dis- Fish and Game Department in the late 19301s, so cuss what I feel has been one of the major causes for depleted ranges are again believed responsible for the decline among Great Basin herds and one which can the decline in fawn crops. A decline of fawn crops be corrected by management. This involves the gener- also occurred on the Fish Lake National Forest in ally lower fawn crops which have resulted, I believe, central Utah, but they started at a period inter- from deteriorating ranges, caused primarily from ex- mediate to that of Duck Creek and the Dixie. Fawn cessive deer use. Deer highlining or hedging of pre- crops of 92 to 100 were recorded for 1930, 1937, ferred browse has long been recognized as a sign of and 1939, but they dropped to 87 in 1940; 75 in excessive use, but less recognized has been the more 1941; and 71 in 1942 (Olson and Turpin, 1931; subtle disappearance of preferred forbs on the sum- Costley, 1938; Robinette, 1950). On the Pahvant mer ranges. For many of the Great Basin herds the Range, which is a part of the Fish Lake Forest, summer range is even more critical for optimum pro- the values were 90 for 1939 (well after overstock- ductivity than winter ranges. Several herds for ing was first recognized); 82 in 1940; and an which I have fall composition counts had 100 fawns average of only 68 for 12 years (1941-42, 1946, per 100 does even when the herds were approaching 1949-57) when classifications were made (Robinette, or at peak numbers. However, after widespread unpublished data). range damage, the fawn crops generally fell into the 60 to 70 range. In many of these herds the decrease An area on which I made a rather intensive in fawn production-equals the present legal kill. deer herd study, the Oak Creek drainage in west central Utah, showed a similar decline in fawn pro- Fall fawn crops of 100 or more were recorded for duction and one almost certainly resulting from the Duck Creek herd in eastern Nevada for 1942, 1943, summer range depletion. Limited classifications by and 1944, but they dropped to around 90 for 1945 and myself and Costley (1940) indicated a fawn crop of 1946 and even further to an average of 73 for the 100 percent for 1939. The herd was heavily damaging 6 subsequent years (Aldous 1948; Robinette, unpub- its range at that time; and despite substantial doe lished data). The decline continued despite the removals beginning in 1940, which perhaps reduced introduction of "1080" in 1947 which drastically herd.numbers to one-half in 1946, the relief was

125 Mule Deer Mortality from V&ouq Causes insufficient for summer range recovery. From the fall the first week postpartum declined from 10 to 4 per- of 1946 through 1957 when my study was made, fall fawn cent. crops averaged but 68 percent or nearly one-third less than in 1939. The lower fawn crops prevailed despite A comparative study of two wild herds in the a substantial reduction in deer numbers, cattle use, Great Basin provided corroborative evidence for the and even coyote numbers during part of the study. importance of preferred forage during summer to opti- Failure of the preferred deer forbs to recover was mum herd productivity (Julander et al., 1961). Sum- evident from observations within a set of exclosures mer range on the Sublett unit of southern Idaho was established by the Utah Fish and Game Department in found to have substantially more preferred deer for- 1952. A check which I made in July, 1971, revealed age than the Antimony unit of south-central Utah. that 9 forbs palatable to deer had a canopy ground There was 50 times more good deer forage per acre coverage of 29 percent in the deer exclosure compared in the aspen type on the Sublett unit than on the to only 2 percent in an adjacent exclosure which per- Antimony area and 11 times more in the mountain shrub mitted deer to feed but excluded livestock. The ex- type. In addition, deer stocking on the Sublett unit closures were not constructed until several years was only half that of the Antimony unit. Sublett after peak deer use so that it's entirely possible deer weights were substantially higher as was the that some of the most palatable forbs had already been fetal rate of 1.85 per doe compared to 1.19 for eliminated from the site. Antimony. Fall composition counts indicated around 50 fawns per 100 does for Antimony and double this The Oak Creek winter range was generally con- for the Sublett. sidered to be in reasonably good condition, but even here there was evidence that the most palatable shrub, I have a feeling that had not the Oak Creek sum- bitterbrush (Purshia tridentata) , was not regenerating mer range been so depleted by overuse in the late itself satisfactorily. A growth ring count made in 1930's and early 1940fs, it could have adequately 1958 of all bitterbrush plants from a plot 15 x 30 supported the post-hunt density of 1 deer per 15 feet on a productive bitterbrush site revealed that acres that prevailed during the 1947-56 study. If the youngest plant of 22 years dated back to 1936. this assumption is accepted and two other reasonable This was about the time when the herd was probably assumptions are made (that the does reproduced at the nearing or at carrying capacity. Observations at 1.85 rate achieved by the Sublet herd rather than the Oak Creek make it quite evident that merely reducing actual 1.32 and that the fawn loss from birth to the a herd is no assurance that damaged ranges will re- hunt was a reasonable 15 percent instead of the cover. Deer numbers must be reduced below carrying actual 33 percent), the herd's fall fawn production capacity and held there until the range can recover. would have been an estimated 1,753 instead of 932. The average legal kill was 447 per year during the Many deer workers have noted the adverse in- study, a value which seemingly could have more than fluence of severe winters upon herd productivity. doubled had the herd realized its full potential. Not only may deer be lost outright through starvation, but because the surviving does are in poor condition, It is doubtful that any Great Basin deer herd has the subsequent fawn loss may likewise be been stabilized through hunting before damaging its severe. The most practical means of minimizing such range. Even the Sublett herd with its excellent losses is to maintain a stocking of deer that will summer range had depleted its winter range along the insure maintenance of the preferred forage species. south side of the Raft River Mountains in Utah. This insures a forage surplus for times of stress on Even though hunting, starvation losses, and lowered which the herd can rely. This view was emphasized fawn production have combined to reduce many Great by results of winter mortality studies of some Utah Basin herds, it is doubtful if the reductions were herds following the winter of 1948-49 (Robinette et great enough and made soon enough to have permitted al., 1952). This winter was considered to have been full range recovery. the most severe by the U. S. Weather Bureau since the inception of weather records in Utah. The herd Several long-term range studies with livestock loss on the South Oak Creek range where there was an have shown that moderate stocking provides greater abundant supply of cliffrose (Cowania stansburiana), economic returns than excessive stocking. Moderate a preferred winter browse, was only 9 percent. This stocking insures adequate supplies of the preferred was in contrast to losses of 20 to 50 percent on other forage and this in turn provides for higher yields ranges within 100 miles where there was little pre- of meat and production of young (Hutchings, 1954; ferred browse. The more forage available to a deer Johnson, 1953; Klipple and Costello, 1960). By the over winter, the greater its chances for survival. same token, it is possible for a well-managed deer The deer not only expends less energy in filling it- herd to produce as many or more animals for hunter self but its opportunity for selecting palatable take than a herd twice the size on overstocked species and the more nutritious plant parts is en- range. hanced, thereby insuring a better diet. In years past, many game managers have been Longhurst et al. (1968) concluded that penned guided in their recommendations for deer removals by deer did best on forage species that they preferred. utilization data on preferred winter browse. This Similarly, a captive herd at the Denver Federal is perhaps good if there is some built-in assurance Center responded dramatically to increased rations of that the key browse species are regenerating them- preferred foods (Robinette et al., 1973). When the selves, but too often this has not been the case. deer were fed increased quantities of hydroponically- On ranges such as Oak Creek where the summer range grown barley and a commercial concentrate, both of is even more critical to the herd's welfare than which they preferred over alfalfa hay, several im- the winter range, there have been few, if any, portant things happened. Food consumption rose, vegetative transects for the purpose of determining weights increased, fawn production jumped from 1.4 to condition and trend among the preferred forbs. 1.9 per doe of breeding age, while fawn mortality of

Mule Deer Mortality from Various Causes Deer management has come a long way in the past on captive mule deer. J. Wildl. Manage. 37(3): three or four decades, but it is unfortunately true 312-326. that sportsmen still pack such a political wallop that they can effectively negate needed herd reductions. , 0. Julander, J. S. Gashwiler, and If winter starvation losses or lowered fawn production J. G. Smith. 1952. Winter mortality of mule result in poorer hunting, the sportsmen usually clamor deer in Utah in relation to range condition. for buck hunting only, or even complete closure until J. Wildl. Manage. 16:289-299. the herd can recover. In actuality, starvation losses and lowered fawn production are firm evidence for the need of even further herd reductions. Rehabilitation of depleted deer ranges will take time, whether accomplished artificially or through natural recovery, and will probably necessitate even further herd reductions. The long-term potential for increased hunter take, however, would seem to make the program worthwhile.

Bibliography

Aldous, C. M. 1948. Control of deer irruptions in Nevada. U.S. Detp. Inter., Fish & Wildl. Ser., Washington, D. C., Spec. Sci. Rep. 57, 16 pp.

Costley, R. J. 1938. Deer classifications on the Beaver District of the Fish Lake Forest. U.S. For. Serv., Ogden, Utah. 2 pp. Typescript.

. 1940. Oak Creek deer herd. Report to Regional Forester, U.S. For. Serv., Ogden, Utah. 2 pp. Typescript.

Hutchings, S. S. 1954. Managing winter sheep range for greater profit. U.S. Dept. Agric. Farmers' Bull. 2067, 46 pp.

Johnson, W. M. 1953. Effect of grazing intensity upon vegetation, and cattle gains on ponderosa pine-bunchgrass ranges of the Front Range of Colorado. U.S. Dept. Agric. Circ. 929, 36 pp.

Julander, O., W. L. Robinette, and D. A. Jones. 1961. Relation of summer range condition to mule deer herd productivity. J. Wildl. Manage. 25(1): 54-60.

Klipple, G. E. and D. F. Costello. 1960. Vegetation and cattle responses to different intensities of grazing on short-grass ranges on the Central Great Plains. U.S. Dept. Agric. Tech. Bull. 1216, 82 pp.

Longhurst, W. M., H. K. Oh, M. B. Jones, and R. E. Kepner. 1968. A basis for the palatability of deer forage plants. Trans. N. Am. Wildl. and Nat. Res. Conf . 33:182-192.

Noel, F. C. 1948. Deer classifications, Dixie National Forest. U.S. For. Serv., Cedar City, Utah. 1 p. Typescript.

Olson, 0. A. and R. L. Turpin. 1931. Inspection report, Beaver District, Fish Lake National Forest. U.S. For. Serv., Ogden, Utah. Typescript.

Robinette, W. L. 1950. Studies of the mule deer herd of the Fish Lake National Forest, Utah. U.S. Fish & Wildl. Serv. 83 pp. Typescript.

, H. C. Baer, R. E. Pillmore, and C. E. Knittle. 1973. Effects of nutritional change

17.7 Mule Deer MortaZitu from Various Causes PROBABLE CAUSES OF THE RECENT DECLINE OF MULE DEER

IN WESTERN U.S.--A SUMMARY

W. Leslie Pengelly Wildlife Biologist

Wildlife Biology Program University of Montana Missoula, Montana 59801

Abstract

The solutions to mule deer management seem simple to many people. However, in reality this is not the case. In fact, deer management is still in its infancy and is understood only in part by even the best biologists. Perhaps the most cheerful way to look at low mule deer numbers is to look back at populations in 1900. This makes present-day mule deer numbers look great. Winter "die-offs" as a result of poor ranges and overpopulations initiated increases in harvests to reduce mule deer numbers. These increased harvests have resulted in a kill of over six million deer in recent years. Except for the effect of hunting, indications are that when deer are on a high quality diet, other environmental factors are not as important.

I approach this assignment of summarizing the is to write your report on a magic slate. Then fact and the fiction associated with the alleged de- you can rip it off if you see anybody approaching. cline of mule deer with the same enthusiasm that Marie Antoinette approached the scaffold. If it As you can see, I'm in a great mood for this weren't for the honor of it, I think I'd decline the assignment. I'm not even sure at the end of these trip. Other titles for such a summary could be two days whether the mule deer are declining or not. equally appropriate--"A Pooling of Ignorance" or After listening to Bruce Gill, one may wonder if "What Do We Know For Sure?"--because we seem to be this meeting was even necessary. We could say, discussing more of what we don't know than what we without too much fear of contradiction, that there do. If I were to paraphrase this situation, I would probably were fewer deer in 1975 than there were in say that learning anything about the mule deer de- the 1960ts, and then we can say that there are a lot cline at this conference is like learning about love more deer now than there were in 1900. Instead of in a brothel. The lessons are clear but oversimpli- telling the public about the high deer numbers in f ied. 1960, we ought to compare today's populations with the 1900 estimates and then conditions wouldn't Anyone attempting to summarize this conference appear so gloomy. in 30 minutes has to be foolhardy, and it just occurred to me why I was asked to do this. As one If the deer are actually declining, I think the wag says, "If he seems lost in thought, it's becuase answer is quite simple. It's only because mortality it's such unfamiliar territory." I tried to antici- is exceeding natality, so now we can all go home. pate what would be said atsthis conference by not What we're really trying to do, though, is determine writing to any of the speakers. They anticipated it if this is the case so we can proceed with the audit by not sending me any advance copies. Everything and find out who tapped the buckskin till. How I've had to do here is what any one of you could about that for mixing metaphors? Our profession has have done, and that is ask your neighbors, read the been described by some of its detractors as a form Transactions and various journals, and go through the of slipshod animal husbandry. This is something I popular literature. I even thought about going into think we should consider. In a recent Audubon the airport newsstand on the way down to see if the article describing the grizzly bear controversy, latest Outdoor Life had the problem solved. That's Bill Gilbert wrote down all the conflicting arguments probably where it will first come out. My suggestion in embarrassing detail. At one point he paused and for anybody working on such a topic in the future,

129 Probable Causes of the Recent Decline said, "So much for the art of wildlife management." thing, and they wrote it down. I think we have in- What a put down. stitutionalized it and it's probably true.

The pattern of the alleged decline, whatever it The reason most often quoted for the alleged de- is, seems to have been repeated in all the states cline is overhunting, but it's by no means uniformly simultaneously. Since all the workers in all the true. A unique, and probably odd, characteristic of deer states involved seem to write to each other, and this two-day conference has been that there hasn't then average out the results, this is not surprising. been one speaker discussing the removal of mule deer But let's assume that mule deer numbers are down from by the gun. Approximately 6 million deer have been the peak populations of twenty years ago, and then harvested in the llwestern states in the last 10 seek the probable answers. Bud Phelps gave us one years. If 6 million deer have been removed by hunt- when he said, "In Utah we intended to knock deer ing, including many females, it is probable that we numbers down--we had too many." We tell them that have had some effect on the slope of the population in Montana, too. It's analogous to the bear at curve. Game departments then say, ''We intended to Yellowstone Park. When the tourists complain about reduce the populations"; but simultaneously they seem not seeing any bears they are told that they're up to reject the notion that hunting is a significant in the hills picking huckleberries. We need an mortality factor. This latter notion seems to be equivalent of that when the public asks us where the changing recently. deer are. On the other side of the question, we use that The 1940's was the turning point in mule deer same theme of hunter removal by talking about the numbers, with notable increases recorded in most of effects of early market hunting. They overharvested the western states. We can show that the deer have deer in many cases, to the point of extinction in declined since then in direct proportion to the in- some areas. The history of deer management always crease in professional wildlife managers. This is includes reference that predator reduction, creation called a nonsense correlation. When it is shown of game refuges, and reduced legal and illegal har- that 90 percent of all the train wrecks involve the vests, coupled with "bucks only'' seasons, helped caboose, the solution is to take off the caboose. bring back the deer. You can find this sequence in We're doing similar things, I think, in the field of almost everybody's summary. So, we've got some wildlife management. strong cases for a wide variety of poqsibilities for the decline, excluding sunspots, aerosol sprays, or We did hire a lot of professionally trained something that somebody is putting in the water in wildlife biologists with the newly available PR funds. the nature of an anti-fertility substance. I don't Simultaneously, we had some tremendous deer die-offs think we ought to be surprised that some factors are in the winters of 1948 and 1950, which made a lot of compensatory. Our job is to unravel these complex- headlines all over the West. Hay and pellets were ities. Low and Julander pointed out that the decline airlifted in to livestock, as well as deer, and the began in Utah approximately 10 years ago, but it new game managers dove right into the fray. They varies in states--some earlier, some later, and some put on pressure to increase the harvest in order to unsure. offset the twin calamities of starvation and land depredation. About the same time, the ranching If we have removed about 6 million deer by legal interests were attempting to force the sale of hunting, I'd like to know why it hasn't been men- public grazing land. The significance of that will tioned here. The 1972 proceedings of the Western come a little bit later. The available harvest re- Association, which deals with the harvest in 1972, cords indicate a rapid increase in deer numbers in listed approximately a half a million deer taken in the past 25 years. We've also increased the hunter 1972-73. The years 1974-76 are not listed, but if numbers, liberalized the seasons, and increased so, an additional estimated 2 million harvested deer access by putting many more roads into formerly have not been accounted for. We've had plenty of inaccessible areas. In other words, game management time to double those existing herds if hunting pres- has been characterized by an ultraliberal approach-- sure were the major depressant. Of the 11 western "a 20-year blood-letting" according to some--and how states reporting in 1972 on the mule deer decline, we're having withdrawal symptoms. the following states indicated that their deer were increasing. Utah said they were up 10 percent; Mon- Many of the speakers at this conference have tana passed on the issue; Colorado was up 10%; Idaho, pointed out the multiple game bags and the various down; Wyoming, down 20%; California, down 15%; New combinations of seasons that have evolved during this Mexico, down 5%; Oregon, down 37%; Nevada, up 5%; period, mostly trial and error, with new research Arizona, down 39%; and Washington, down 30%. It is findings being applied as fast as the public would hard to tell what has happened in the last few years. accept them. Each state has its own peculiar history Prom a variety of sources, I found mule deer harvest with non-residents , license fees, and landowner- figures estimated for 1946 for the western states sportsman problems. Now we are all facing a public that totalled 275,000. By 1959, harvest had jumped reaction to reduce this liberal management program, to 688,000; by 1962, it was 770,000; 1967, down to and most state agencies tacitly admit that deer num- 588,000; and 1972--507,000. There were some signs bers may be lower than we care to admit. Wolfe and of recovery in a few places, but not too many. Then others have commented upon how the various states I began to look at the way the data were collected arrive at their population data. The increases and and listed the categories that we ought to have if decreases can be due to a host of things that have we're going to discuss these things. nothing to do with the total number of animals. The first thing any student learns in wildlife management I listed each state's response to harvest, to is that a total census is probably something that he number of hunters, to cripple and illegal kills, to won't be able to do. I remember writing that down as predators, to range condition, to competition with a student in 1946. Last week I told a class the same livestock, to competition with other wildlife, to

Pi3obabZe Causes of the Recent Decline 130 disease, to habitat loss, and then to miscellaneous collecting data, and some states are not even bother- factors. Each of the 11 states reporting was tallied ing. The state of Washington derives its harvest by category with many going unreported. The only data from a card questionnaire. Managers estimate thing common to all states were harvest figures, that the state has deer populations in three differ- hunter figures, and a few random observations, the ent densities: medium, heavy, and low. The harvest kind you can get down at the local pub, and probably data are derived from this, and they extrapolate with more enthusiasm. So that was not very useful. backwards to calculate how many deer they estimate Almost no two states used the same systems for har- for a given area, Washington also solves its game vest collection; no state has used its own system damage problems and winter range shortages with without change for more than a brief period of time; fences and artificial feeding in some areas. a few states lumped the species together and then guessed how many of them were mule deer. Every state Another subject receiving scant attention at has a continually evolving system of sex, age, time, this conference is the extent of wounding losses. and area restrictions, changing license fee structure, Colorado uses a 5 percent additional figure for and changing non-resident quotas. There are so many wounding loss on bucks-only hunts and a 10 percent variables that it makes you wonder if you'd blow with either-sex hunts. A recent New Mexico study every fuse in town if you put this through the com- showed 92 percent one year, and 93 percent two years puter. later of cripple and illegal losses. In other words, non-legal mortality by the gun may be nearly match- The hunter harvest data are almost always a ing the harvest. If we took 6-8 million deer out of year late, they arrive aftep the seasons are set, and this 11 western state complex by hunting, are we may reflect political pressure as much as herd con- willing to add another 6-8 million for cripple and dition. Colorado and Utah have good mule deer habi- illegal loss? I think that as we start adding these tat, and both of these states recorded increases in losses up, we can probably show that somebody owes 1972. Utah is 11th in area, with about 85,000 square us deer. miles; Colorado is 8th largest, with 104,000 square miles, and yet they are among the leading producers The political aspects of deer management are of mule deer year after year. An inspection of a worth a comnent or two. I have spent the last three vegetation map of Colorado reveals that only half and a half years on the Montana Fish and Game Com- the state would qualify as habitat for mule deer. mission, and now sit on the other side of the table From that half, you start eliminating poor deer listening to slogans, jargon, cliches, platitudes, habitat, and you end up with scattered remnants of and tautologies. Collectively it's called scientific deer range. My conclusion, from this cursory look, management. Biology is only one facet of management. is that Colorado, with a limited acreage and a very The other considerations include the political, legal, good deer habitat, has consistently produced high social, cultural, economic, and whatever. Let me numbers per unit, even in the face of oil shale de- read you two sentences out of a politically oriented velopment and subdivisions. Utah is also probably statement from a Nevada Game Commission member producing about as many deer as it can, considering shortly after the Director of the Bureau of Land the land use changes of the recent past. Montana is Management said, "We're going to improve the ranges the 4th largest state (147,000 square miles) and in Nevada." It's two pages long, but I'll only read second in the deer harvested in 1972. It has exper- these two paragraphs. It says: ienced declines since then and so is now lagging behind Utah and Colorado. Montana has mule deer over "Today you could remove all the entire state but not uniformly spread. Mule deer livestock from Nevada ranges and are found in the forested areas of the western part never hunt deer again. Without of the state, where logging operations produce sera1 doing anything more, in a short shrubs. In other regions of the state, mule deer period of time the ranges would be are found in foothill ranges combining forested and in a worse condition, and the deer grazing areas. The high plains grassland country in herds would continue to dwindle." the Glasgow area is not as productive for mule deer as is the Miles City region, but it still outproduces "In closing, I'd like to say the forested district of western Montana. that not only is it proven that livestock and wildlife are compat- Last night Dan Poole suggested that we should ible, but that they are desirable. develop some kind of a uniform breakdown by habitat We, therefore, defend the live- quality involving cooperation between states where stock industry in the state of ecosystems overlap. It isn't likely to occur because Nevada and feel that is the wild- of one failing, and that is human inertia. We life and the sportsman ever had a probably just won't get around to it. The demand for friend, it would be a rancher.'' huntable deer, however, is going to continue. We aren't going to slow that down. Dick Mackie missed that point yesterday in his literature survey. He said he didn't know it had Free-lance writers are sending lengthy question- been proven that cattle and deer were good for each naires to state game agencies asking for all sorts of other, but here we have it. It's a political proof, information on the deer situation and usually con- but it's one that we'll probably hear more of. Dean clude by saying, "We certainly appreciate your help." Thad Box talked to you yesterday about more people We could spend many months each year answering these on the same amount of land with increasing pressures, requests which are only exceeded in their demands by and he said the answer is allocation. Allocations those coming from the agencies or organizations that may be based on stronger political than biological are about to write a book. We can see that this form rationale, but I'm sure the proponents will stress of data collection and reporting results is a hap- the need for cooperation. There's an old anecdote hazard system. We don't have any uniform manner of

131 Probable Causes of the Recent Decline about cooperation that says: "There's room enough No one in this audience challenged it, although for one of us on this piano bench if you'll get off.'' Tueller from Nevada did comment on it. This debate needs to be continued. At the recent (1976) N.A. Wildlife and Natural Resources Conference in Washington D.C., a fish and Wolfe was telling us, in effect, to challenge game biologist, Steve Gallizioli, stated that, "In assumptions. The computer can't overcome poor in- Arizona, the single most important range management puts. I've got a hunch that maybe we'll have to problem which limits the attainment of potential fish admit that there are some things we just can't do, and wildlife benefits is overgrazing by livestock. I like nailing jello on the wall, or putting the tooth- believe the problem is not unique to our state." paste back in the tube. Wamlmo, Reid, and Carpenter Speakers at this conference (Mackie, Urness, Tueller) analyzed existing data in Colorado to provide clues seemed reluctant to confirm this observation. for the decline, and they concluded that their meager data failed to support the hypothesis that all these Enough of this short course on public relations things, singly or in combination, could be held on public lands. When we get to the point where we've responsible. That's the approach the Chamber of got enough feed for either the cow or the deer, but Commerce uses when you tell them that air pollution not enough for both, I think we'll find out how much is causing a problem. I would like to have heard cooperation is going to take place. The statement them say that the meager data failed to support the from the Nevada Conmission shows that when the po- hypothesis that all these things are not responsible. litical pressures are on, all those great stochastic There are some pragmatic aspects to consider. If perturbations that statisticians alarm me with really deer are not in evidence, something must have hap- don't count for much in the management decision. pened to them. Longhurst said that the shift to cattle from sheep in California was detrimental to Let's move on to some of the other subjects. mule deer, and on annual grass ranges that may well Dick Denney got into the question of population regu- be. Sheep can be far more easily manipulated on lations and raised the question, "Is the deer decline ranges than livestock. That may be what he had in a sign of ecosystem deterioration?" Practically mind when he said that the increase in cattle and everything we've heard at this conference indicates decline of sheep was detrimental to deer ranges. that when deer are on a high quality diet, other environmental factors are not as important. Speakers ,rueller made the observation that deer numbers discussing predation and winter survival have also decline in proportion to lack of vegetative diver- stressed the overriding importance of good nutrition. sity. That's in every basic text on ecology I've Zwank stressed the importance of nutrition in fawn ever seen. We talk about the stability of diversity, survival. and yet biologists have been guilty of aiding and abetting ecological insults. We spray ranges, we Hornocker and Knowlton reviewed much of the same poison ponds with toxaphene, we've suggested mass material that 1 did on predation. Hornocker pointed burning of forests to produce monocultures, and out that no correlation exists between deer numbers we're probably guilty of other ecological insults and lions in most areas. There has to be some other on a large scale without really knowing what the correlation. He talked about the importance of the consequences are. effect, not the fact, of predation, and I think the same idea was stressed by Knowlton. Hornocker missed Another point that Tueller made that's worth the best quote from Durward Allen, whose grandmother repeating is that not all forage produced can be watched his dog run the cat up the tree. She said, shown to directly influence productivity. We feel "Oh, Lord, why can't they be nice." Predators have that food is important, but it may not be the only a poor press, and I think that when we get into limiting factor. There are many cases where we've public relations, that's probably how we ought to increased forage supplies without increasing the an- approach it. Knowlton was quite candid when he said imal numbers. The fact that deer are seen in an "maybe" in regard to whether predation was a signifi- area doesn't mean that they are produced there. We cant limiting factor. The nutritional aspect is may be shifting them or drawing them from one area obvious in his work--healthy deer can withstand more to another. predation by compensatory reproduction than can deer on low quality ranges. Neither Hornocker nor Knowlton I want to comment on the use of jargon in our said that the removal of the coyote or the lion could profession. We smirk when a sociologist defines be proven to help deer. The average wildlife biolo- murder as accelerated, interpersonal altercation, gist is poorly equipped to evaluate nutritional fac- but wildlifers aren't above doing their bit to in- tors. He ships plants to somebody else for proximate crease the fog index either. Here's an example from analysis. Then we find out that that's only the be- the Master Plan for Grand Teton National Park. "New ginning. Volatile oils that are bactericidal and insights gleaned from recent problem-oriented re- fungicidal upset all the calculations based on pro- search within the parks suggest that environmentally tein levels. Synergistic effects cause foodstuffs to regulated ecosystems can ultimately be reestablished. act differently in combinations. Just switching the For example, research has suggested that the popu- combinations on two species in eight different combi- lation may tend to be self-regulating without the nations would blow your mind, and some of the animals presence of significant predator populations. In the eat as many as 20 different kinds of plants. You can context of increasing knowledge of these factors, appreciate what Nagy and his colleague talked about park management will continue to work toward the today--the need for more basic research of high quali- elimination of hunting in the park." The state of ty. Several speakers quoted the Kaibab case in the Wyoming responded more succinctly saying, "To hell face of articles in BioScience, Ecology, and various you will." National Park releases pointing out that the Kaibab deer irruption really never occurred, that it was a I'd like to make a brief comment on the wildlife figment of someone's imagination, or a clerical error. disease paper. It was of interest to me because in

Probak Ze Causes of the Recent Dee line 13? our zeal to rid the ranges of the predators, we feel put our funds into other areas because of the public we're helping the herbivores. Now we're finding out relations aspects. We have a need for more internal in some cases that carnivores and herbivores are vec- cost accounting and planning to see where the money tors for other diseases. If we do have these reser- has gone. We may be startled by the amount of money voirs of infection with livestock and wildlife inter- that goes into some research projects when it is changing, we've got some real problems: Brucellosis finally summarized. Game departments are now faced is found in the bison in Yellowstone and every time a with a rash of legislative interventions after many Park bison crosses the Montana line, by law we have to years of relatively free sailing. It seems to be kill it due to stockmen's fears. I think you can see our turn. Eisenhower once said, "I don't think we the consequences. We've taken an animal that evolved need easier problems, I think we need better men.'' from ancient times and juxtaposed it with a domestic How selective have we been in our hiring practices animal. Since sick animals are predisposed to losses in wildlife agencies? We've hired a lot of people by predation and accidents, it is difficult to assess in the past 30 years. Perhaps what I'm suggesting is the nature and extent of the losses. that we've been getting along in a rather slip-shod fashion which won't work now that we're getting into THE FUTURE the big leagues. The research has got to be better and deeper, and I don't think the universities, at Robinette told us that it would have been great present, are preparing the personnel to do it. They if we could have cut the deer numbers down before the are reflecting the market. You can't get a job in range was damaged so severaly, and many authors have some of the federal agencies if they're in a de- pointed out previously that when deer exist on second- clining budget year because they have to do what they class forage, periodic die-offs can be expected in call "GS averaging.'' If you've got the home office severe winters. We need far more experimental evi- full of 15's and 16's, you've got to hire 3's and dence of that fact. Looking into the future, I think 4's so you'll average out at 12. Some of the agen- that we can agree that simple minds seek simple solu- cies have really not made much of an effort to im- tions. Some of you are going to go home disappointed prove the quality of their people. because I didn't tell you the solution to the mystery of the deer decline. The conference speakers didn't Thad Box pointed out that 12 credits is the tell me the answer either. The answer may be that we minimum Civil Service requirement to be a range should challenge the basic assumptions under which we examiner. I submit that 12 credits in range hardly have been managing deer these past 30 years. The qualifies one to go out and make decisions influ- demand for more hunting opportunity can go no way but encing the future of the public lands as well as the up. It seems to be increasing despite all the handi- financial welfare of many citizens. Game damage caps we've imposed upon the hunters, and the rate of complaints are increasing in the western states, and increase is still as rapid as the increases in the it has become a very serious issue. Fish and game 60's. The hunter himself appears to be becoming less commissioners and the other politically appointed skillful, more reliant on equipment, more reliant on administrative types deal with axe handle measure- somebody else to write him a book on how to hunt, how ments, the game manager follows along with a yard- to build a fire, and how to dress out a deer. I think stick, and the researcher is measuring stuff to four he's going to be subject to far more regimentation, decimal places. This is particularly ironic when more restrictions, quotas, permits, places, limited we can't even make one simple breakdown, such as are access, all these things. Hunters are also going to we gaining, losing, or holding our own on mule deer? be subject to the whims and vagaries of political Those are class intevals of 33 113 percent. I'm pressure, which they may not be a part of, and they not really impressed with decimal points. I'd like may not understand the reasons. There is going to be to know if we have such a thing as a "lack of con- more pressure on land managers to produce quality f idence" interval? hunting experiences, and to provide better number distribution. There will be more ant i-nonresident senti- Tha land itself is obviously under continually ment. The provincialism in our own state is pretty increasing pressure. Land is finite and recreational obvious. Simultaneously, we're being challenged by pressures are in addition to all the traditional court cases, which may cause us to repay all the non- uses. We can't buy all the needed game ranges and resident license differentials back to 1970. This are going to have to learn to get along with what we would mean that we'll probably sell the place and go have. This is going to involve a degree of coopera- into another line of work. tion, which has heretofore been unknown between the agencies. Arizona charges an extra fee to hunt on The anti-hunter pressure is expected to increase lands that they have improved. I think it's a good everywhere, which may shift the deer harvest from the idea. A $5 fee to hunt on the Kaibab might be the hunter to the coyote. California's recent report by right way to finance the studies, because we may soon Longhurst and his colleagues said rather gloomily, "We run out of dollars. The demand for the deer is don't think we can stem the tide of habitat destruc- obviously going to exceed the supply. More buck tion and anti-hunter pressures." California is kind hunting and less trophy hunting will be the rule. of a bellwether here. They've had the problems longer Colorado is already going for less trophy hunting and than other states. more meat. This is just the opposite of what they"re finding on African game ranges where they shoot bucks The game departments are faced with increasing and fawns. They don't shoot their productive herd costs, and increasing demands for more complex infor- segments. Why the difference? I think the trade- mation, and simultaneously they are facing a reduc- offs between the deer or elk and livestock are going tion in income. Even I can figure out what that to be hard fought. Remember that some game depart- means. We are probably going to have to put more ments, under political pressure, don't provide much money into non-game activities, and I don't think it of a fight when the livestock interests remind them will come fast enough to fill in the gap between now of their loyalties. and when the legislature does it. So we're having to

133 Probable Causes of the Recent Decline Crippling losses will probably increase. Long- Just consider what $700,000 could be used for in range shooting, fear of fines (abandonment of does other projects. If you don't have a winter range, and yearling bucks), more illegal hunting because you go to the substitute. more restrictions make it more possible to hunt illegally, and a probable increase in poaching can Deer losses to accidents are very likely going be expected. Wildlife diseases will probably in- to increase with more roads, more fences, more reser- crease, as Dr. Hayes mentioned, with the increase in voirs, and more ditches. I don't see how we can pre- stocking on public lands and with resultant poor dict the future of deer habitat except that we'll nutrition. The sad thing is that there are probably continue to lose more of it. What habitat we do have very few wildlifers and probably no hunters that know can be manipulated with the use of fire, and the con- anything about wildlife diseases. We generally note trol of fire. But I think the qualitative losses, in our reports that disease did not seem to be a such as from overuse, are bound to increase. The problem, perhaps because we don't recognize it. An quantitative aspects of habitat loss pose an endless, old Ozark hillbilly said, "We're generally down on one-way attrition. Twenty thousand acres a year are what we ain't up on." Predation will probably in- converted from one kind of agricultural use to crease as the habitat shrinks, or degenerates, and another, and a million acres a year is lost under the it may decrease if the public demands more predator freeways. It takes 60 acres to build an interchange. control. That's a toss-up. Starvation can be con- The new national plant will probably be a cloverleaf. trolled by reducing deer numbers if other forms of We'll be lucky to level off the mule deer losses range competition do not exist, or it may be brought and then fight to hold our own in the face of these about by changes in the weather, which we can't do endless problems. anything about. We can improve the ranges at great cost, and discover that it helps cattle at the ex- In closing, I'd like to quote from Santayana, pense of deer. The public may end up insisting on who said, "All problems are divided into two classes. an artificial feeding program like that at Jackson Soluble questions, which are trivial; and important Hole where the state plus the federal government put questions, which are insoluble." Thank you. out $700,0000+ annually for supplemental feed for elk.

ProbabZe Causes of the Recent Decline