Status and Distribution of Barbary Sheep in the Southwest U.S

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DESERT BIGHO COUNCIL 1981 TRANSACTIONS

A Compilation Of Papers Presented At The 25th Annual Meeting, April 8-10, 1981, Kerrville, Texas

Editorial Board: Charles L. Douglas. Chairman Thomas D. Bunch Copies available for $5.00 by writing the Paul R. Krausman Desert Bighorn Council. David M. Leslie, Jr. Death Valley National Monument J. Juan Spillett Death Valley, CA 92328 DESERT BIGHORN COUNCIL 1981-82 OFFICERS: Chairman: Jack Kilpatric, Texas Parks and Wildlife Dept. Vice Chairman: Bob Glaze, Glaze Veterinarian Clinic Past Chairman: Carl Mahon, Bureau of Land Management Secretary-Treasurer: Peter G. Sanchez, NPS, Death Valley National Monument

TECHNICAL STAFF: Lanny 0. Wilson (Chairman), James A. Blaisdell, Warren Kelly, Richard Weaver, James DeForge, George Welsh, Dr. Juan Spillett,

BOOK EDITORS: Lowell Sumner and Gale Monson COMMITTEE CHAIRMEN: Constitution: David Dunaway and Lanny Wilson Nominations: Dick Weaver Program: Bob McQuivey Arrangements: Bob West Transactions: Charles L. Douglas Publicity: Lew Carpenter Burro: Rick Brigham Barbary Sheep: C. David Simpson Ewes: Bonnie Blaisdell and Ruth Kelly Awards: Andy Sandoval Resolutions: Walt Snyder

DESERT BIGHORN COUNCIL MEETINGS AND OFFICERS 1957-1981 ANNUAL MEETINGS

Year Location Chairman Secretary-Treasurer

Las Vegas, Nevada M. Clair Aldous Yuma, Arizona Gale Monson and Warren Kelly Death Valley, California M. Clair Aldous Fred Jones Las Cruces, New Mexico Warren Kelly Fred Jones Hermosillo, Sonora, Mexico John Van den Akker Ralph Welles Grand Canyon, Arizona James Blaisdell Charles Hansen Las Vegas, Nevada Al Ray Jonez Charles Hansen Mexicali, Baja Calif., Mexico Rudolfo Hernandez Corzo Charles Hansen Redlands, California John D. Goodman John P. Russo Silver City; New Mexico Cecil Kennedy John P. Russo Kingtnan, Arizona Calud Lard John P. Russo Las Vegas, Nevada Ray Brechbill John P. Russo Monticello, Utah Ralph and Buddy Welles W. Glen Bradley Bishop, California William Graf W. Glen Bradley Santa Fe, New Mexico Richard Weaver Tillie Barling Tucson, Arizona George W. Welsh Doris Weaver Hawthorne, Nevada Warren Kelly Doris Weaver Moab, Utah Carl Mahon Lanny Wilson Indio, California Bonnar Blong Lanny Wilson Bahia Kino, Mexico Mario Luis Cossio Lanny Wilson Las Cruces, New Mexico Jerry Gates Peter Sanchez Kingman, Arizona Kelly Neal Peter Sanchez Boulder City, Nevada Bob McQuivey Peter Sanchez St. George, Utah Carl Mahon Peter Sanchez Kerrville, Texas Jack Kilpatric Peter Sanchez DESERT BIGHORN COUNCIL AWARD RECIPIENTS

BIGHORN TROPHY:

Ralph and Florence Welles, US. National Park Service, Death Valley, California Oscar V. Deming, US. Bureau Sport Fisheries and Wildlife, Lakeview, Oregon John P. Russo, Arizona Game and Fish Department, Phoenix, Arizona Charles Hansen, US. Bureau Sport Fisheries and Wildlife, Las Vegas, Nevada Steve James, Jr., Fraternity of the Desert Bighorn, Las Vegas, Nevadh M. Clair Aldoux, US. Bureau Sport Fisheries and Wildlife, Fallon, Nevada The Arizona Desert Bighorn Sheep Society, Inc. Fauna-Silvestre, Mexico City, Mexico Bob McQuivey, Nevada Dept. of Fish and Game, Las Vegas, Nevada

HONOR PLAQUE:

Nevada Operations Office, Atomic Energy Commission, Las Vegas, Nevada Pat Hansen, Bighorn Illustrator Specialist, Death Valley, California lnyo National Forest, Bishop, California Lydia Berry, Clerk-Stenographer, Desert National Wildlife Range, Las Vegas, Nevada Jim Blaisdell, National Park Service, Seattle, Washington Society for the conservation of Bighorn Sheep, Upland, California Dr. Thomas D. Bunch, Dept. of Animal, Dairy, and Veterinary Science, Utah State University, for identifying chronic sinustitis in bighorn and continuing research on control measures. New Mexico Dept. of Game and Fish for their decisive and dramatic efforts to salvage the scabies mite infested desert bighorn population in the San Andres Mountains. Dr. H. Grant Kinzer, Livestock Entomologist, New Mexico State University, for his significant research on new drugs and dosages for controlling scabies mites in free-ranging desert bighorn.

AWARD OF EXCELLENCE:

1975 Gale Monson, Desert Museum, Tucson, Arizona; Lowell Sumner,Glenwood, New Mexico TABLE OF CONTENTS

AN ANALYSIS OF RECREATIONAL USE PATTERNS IN DESERT BIGHORN Page HABITAT: THE PUSCH RIDGE WILDERNESS CASE Ken G. Purdy, William W. Shaw...... 1 TRANSFERRINS OF DESERT BIGHORN IN ARIZONA, NEVADA, AND UTAH Thomas D. Bunch, Paul Webb, J. Juan Spillett...... 5 HISTORY OF BIGHORN TRANSPLANTS ON THE HUMBOLDT NATIONAL FOREST WarrenE.Kelly ...... 7 STATUS AND DISTRIBUTION OF BARBARY SHEEP IN THE SOUTHWEST U.S. C. David Simpson, Leslie J. Krysl...... 9 STRESS: ENVIRONMENTS AND THE EFFECTS ON DESERT BIGHORN SHEEP James R.DeForge ...... 15 GROUP ORGANIZATION AND ACTIVITY PATTERNS OF DESERT BIGHORN SHEEP MaryEllen Chilelli, Paul R. Krausman...... 17 TRANSPLANTING DESERT BIGHORN SHEEP-A REVIEW MaryM.Rowland,JohnL.Schmidt ...... 25 EVALUATION OF A WILD-RELEASE OF DESERT BIGHORN SHEEP James C. deVos, William Ough, Daisan Taylor, Richard Miller, Sandra Walchuk, Richard Remington...... 29 ESTIMATING A BIGHORN POPULATION BY MARK-RECAPTURE Robert C. Furlow, Milton Haderlie, Robert Van den Berge...... 31 ABERRATIONS OF THE TOOTH ARCADE AND MANDIBLE IN DESERT BIGHORN SHEEP Robert L. Glaze, Thomas D. Bunch, Paul Webb...... 33 THE LOSS OF TWO POPULATIONS OF DESERT BIGHORN SHEEP IN CALIFORNIA James R. DeForge, Joan E. Scott, Glenn W. Sudmeier, Richard L. Graham, Stephen V. Segreto...... 36 REINTRODUCTION OF DESERT BIGHORN SHEEP INTO COLORADO NATIONAL MONUMENT RonaldR.Ravey,JohnL.Schmidt ...... 38

Bighorn Illustations by Pat Hansen TABLE OF CONTENTS - STATUS REPORTS - Page 1980 BIGHORN SHEEP STATUS REPORT - UTAH JamesW.Bates ...... 42 ARIZONA BlGHOWN SHEEP STATUS REPORT Richard R.Remington ...... 44 STATUS OF A TRANSPLANTED BIGHORN POPULATION IN ARIZONA USING AN ENCLOSURE JohnR.Morgart,PaulR.Krausman ...... 46 CONDITION AND TREND REPORT FOR THE 1980 SHEEP POPULATIONS IN NEVADA Robert P.McQuivey ...... 50 HISTORY AND STATUS OF BIGHORN SHEEP IN THE GUADALUPE MOUNTAINS, NEW MEXICO Bruce L. Morrison ...... 52 RESULTS OF A DIRECT RELEASE DESERT BIGHORN TRANSPLANT IN THE VIRGIN MOUNTAINS OF NEVADA kobert P. McQuivey, Dave Pulliam...... 55 A SUMMARY OF CAPTURE EFFORTS IN ARIZONA SINCE 1977 JamesC,deVos,Richard Remington ...... 57 STATUS OF THE STONEWALL MOUNTAIN DESERT BIGHORN SHEEP REINTRODUCTION PROJECT OF CENTRAL NEVADA RobertP.McQuivey ...... 60 STATUS OF DESERT BIGHORN SHEEP IN TEXAS - 1981 Charles K.Winkler ...... 63 MOVEMENTS AND MORTALITIES OF DESERT BIGHORN SHEEP IN THE SAN ANDRES MOUNTAINS, NEW MEXICO Richard Munoz ...... 64 NEW MEXICO BIGHORN SHEEP STATUS REPORT - 1981 AndrewV.Sandoval ...... 66 STATUS OF POPULATION MODELING OF THE RIVER MOUNTAIN HERD David M. Leslie, Jr., Charles L. Douglas...... 69

Typesetting & Layout by Shersten Zoller Printed by University of Nevada, Las Vegas

How do people behave in bighorn habitat? How do bighorn AN ANALYSIS OF sheep contribute to the recreational experience of people? And what beliefs do they hold concerning the effects of their RECREATIONAL USE activities on the sheep? Comprehensive evaluations of recreational impacts on bighorn sheep necessitate a greater PATTERNS IN understanding of these human aspects of relationships between recreators and bighorn. Expanding our understanding DESERT BIGHORN of these relationships was the primary purpose of a study conducted from September 1979 to September 1980 in desert HABITAT: bighorn habitat in Pusch Ridge Wilderness (PRW), Arizona. THE PUSGH RIDGE: The background to the problem, study area, methodology and other'details of the study have been described by Purdy and WILDERNESS CASE Shaw (1980). The specific objectives of the study were to:

1. determine numbers and activities of recreators using

, upper reaches of Pima, Finger Rock, and Romero Can- yons (Fig. 1)--popular travel routes in bighorn habitat in PRW-and other interior areas of PRW; Ken G. Purdy and ~illiamW. Shaw School of Renewable Natural Resources 2. determine preferences and perceptions regarding re- University of Arizona sources and management of PRW, for individuals using Tucson, AZ 85721 the areas in objective one;

3. estimate numbers of recreators using lower portlons of Abstract: Recreational use of the Pusch Ridge Wilderness, Pima, Finger Rock, and Romero Canyons; Arizona, may present disturbances to mountain sheep (Ovis canadensis mexicana). This report examines the recreational 4. determine degree of interaction between recreators and uses and users of bighorn habitat in the wilderness area. bighorn sheep in PRW; and Photoelectric trail traffic counters, unmanned survey stations, self-administered questionnaires, telephone surveys, and 5. assess recreational impacts on bighorn sheep in PRW direct observations were used to obtain patterns of recrea- and develop management recommendations. tional use and activity data, to determine the significance of sheep to recreators, and to assess potential bighorn distur- Data were collected using the following techniques and in- bances. Findings indicate that use patterns can be broadly struments: photoelectric trail traffic counters, unmanned described by 2 types of visitors: lower canyon visitors and survev stations, self-administered questionnaires, telephone backcountry visitors. The majority of users are lower canyon surveys, direct observation. visitors and appear to present little threat of bighorn disturbances. While less than 10% of the total users can be considered backcountry visitors, their activities and lengths of stay may pose a greater threat to the bighorns. Backcountry visitors generally believe their activities do not adversely affect the bighorns. However, they do favor recreational use restrictions if necessary for the welfare of the sheep population. Several recommendations are made as safeguards against humanlbighorn sheep conflicts in the wilderness area.

INTRODUCTION The nature of mountain sheep habitat presents a paradox to the welfare of sheep. The aesthetic qualities, psychological benefits, and physical challenges to be.found in many areas occupied by bighorn sheep often serve as lures to outdoor

recreators that desire experiences with those attributes. The TUCSON result can be intensive competition between recreators and sheep for the same resources and space.

Unfortunately, information regarding effects of recreational MILES N use on bighorn populations has been inconclusive. Never- - Wilderness Boundary theless, numerous studies have clearly indicated the irnpor- - - - - Trails tance of evaluating humanlbighorn interactions in order to Study Ares determine the effects of human use on the physiology and Trall Counter Location behavior of bighorn (Nelson 1966, Geist 1971, Graham 1971, Survey Station Location Light and Weaver 1973, Elder 1977, Hicks 1977, DeForge 1980). Although our understanding of bighorns' reactions to specific recreational activities and human actions is limited, we unfortunately have even less knowledge about human aspects of humanlbighorn relationships. This includes the existence of a Figure 1. Area map of Pusch Ridge Wilderness (PRW) recreational relationship between the two, and positive human and locations of research equipment within benefits that may be derived from it. Several questions arise. the study area.

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -1- RESULTS AND DISCUSSION Table 1. Respondents' beliefs concerning the effects Total Trail Use. Data obtained from trail traffic counters of their recreactional activities on bighorn located near trail heads in the study canyons provided overall sheep in Pusch Ridge Wilderness. annual trail use estimates and indicated a minimum of approximately 34,000 visitors. Of that use, 75% was in Pima Can- yon (Fig. 1). Finger Rock Canyon received 19% of the use and Romero Canyon received 6%. Characteristic of the seasonal Personal Activities Do Affect the Sheep trends of recreational use in the Southwest, trail use peaks in (N = 28) 33 % fall and spring and is lowest in summer. Ramifications of Reason: those trends on mating and lambing activities are unknown. Cause sheep to avoid recreational use areas However, earlier reports from Arizona (Russo 1956) suggested Activities displace sheep from habitat that lambing peaked at a time when the human use in PRW may be reducing the amount of suitable lambing sites. Adds to the cumulative effect of recreational use on sheep Observations used to validate the accuracy of trail traffic counts indicated the traffic counters were between 91 and Personal Activities Do Not Affect the Sheep 99% accurate. However, 14 accounts of counter vandalism (N = 47) 56 % necessitated frequent inspections and maintenance in order Reason: to keep the counters operational. Conduct no disturbing activities Unmanned survey stations in Backcountry Uses and Users. Confine activities to hiking trails backcountry areas appeared to be an efficient method for collection of visitor information and allowed estimates of Do not use bighorn habitat areas numbers of people using interior regions of sheep habitat. A If bighorn are not seen, then activities total of 25 hours of observations indicated that 64% of the cannot effect them visitor groups complied by completing a self-administered Bighorn are not afraid of people questionnaire (SAQ). Responses from 844 SAQ's were used to Do not visit PRW frequently enough to evaluate backcountry use of desert bighorn habitat in PRW. effect sheep The 844 backcountry visitor groups surveyed totaled 1,958 peo- Sheep can run away from humans into ple. Expansion of this figure, based on a 64% compliance rate undisturbed areas indicated that 1,384 parties, or more than 3,200 people, travel- Other ed in the backcountry. Although data indicated Pima Canyon received the majority of total trail use (accounted for near the trail head), nearly 60% of the backcountry trail use took place were: 1) geological formations, 2) vegetation, and 3) wildlife, in Finger Rock Canyon (Fig. 1). Pima and Romero Canyons respectively. Other responses included, in order of decreasing received the second and third greatest backcountry trail importance, water, solitude, vistas, and trees. utilization, respectively. Personal interviews indicated that Bighorn Sightings by Backcountry Visitors. Users also were Finger Rock trail users often pursue a popular backcountry asked to report bighorn sheep sightings. Those reports were area destination. The other study canyon users indicated they viewed cautiously. Locations were often general, and few were less inclined to pursue particular destinations in the details were provided to indicate the circumstances of the en- backcountry areas of those trails. counter. Nevertheless, desert bighorn sightings by PRW users appear to be rare occurrences. Only 10 respondents (1%) Characteristics of PRW backcountry visitors and their ac- reported viewing bighorns in PRW. However, 7% reported tivities were extremely similar to those of other wilderness bighorn sightings on previous trips to the area. Of those areas (Hendee et al. 1978). PRW users were predominately sightings, 53% took place at locations in or near Pima Can- male, and 74% of the parties consisted of 1 or 2 individuals. A yon. The greatest frequency of sightings occurred in February length of stay of only 1 day was reported by 78% of the users. and March, and all but 2 of the sightings occurred within the And while the majority of respondents indicated that they had last 5 years. been to the area before, they also reported having only 3 or fewer visits during the previous 12 months. Telephone Survey: Additional Insights. Due to the fact that only a limited amount of information was obtained through the Backcountry users were requested to respond to 4 questions on-site SAQ, a telephone survey of 84 randomly selected SAQ regarding the extent of their off-trail travel. Data indicated respondents was utilized to provide further insights into the most use was limited to hiking on or near the trails. Over backcountry users and uses of PRW. One function of the 20% of the users reported frequently traveling up to Vi mile telephone survey was to allow more complete data to be col- (402 m) from the trail with 14% indicating frequent off-trail ex- lected regarding the sociodemographic characteristics of the cursions of up to % mile (805 m). Additionally, 14% of the users. Again, results were similar to those established in users indicated cross-country travel of greater than V2 mile previous wilderness user studies (Hendee et al. 1978). Users of (805 m) in PRW. Personal observations of bighorn bedding PRW were predominately young and well educated. Mean age sites and other utilization areas in relation to trail locations of respondents was 33, and over 60% possessed 4 or more suggest that off-trail use greater than 1h mile (402 m) will years of college. Nearly 90% of the visitors reside 9 miles or substantially increase the possibility of human interactions less from Tucson. Furthermore, when questioned about the with bighorn sheep. reasons for selection of PRW as a recreational area, nearly 60% of the respondents stated that proximity to Tucson was In an attempt to determine backcountry users' preferences for the resources of the area, including the desert bighorn sheep, the most important factor. No users indicated that the visitors were requested to rank the 3 resources that they found presence of bighorn sheep was the primary reason for visiting PRW. most appealing in PRW. Recreators seldom experience encounters with bighorn sheep in PRW, and less than 1 % of the Telephone survey respondents reported that day hiking was responses specifically indicated bighorn sheep as one of the their primary activity; backpacking was pursued by less than most appealing resources. The 3 most frequent responses 25% of the individuals. Photography and wildlife observation -2- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS Knowledge and Attitudes About Bighorn Sheep. Earlier studies have found that the accuracy of wildlife perception is Table 2. Respondents' preferences regarding recrea- strongly influenced by familiarity or recreational contact with tional use restrictions with a hypothetical. wildlife (Bryan and Jansson 1973). The results of this study ly declining bighorn population suggest that the absence of those factors in many users of PRW does, in fact, decrease the accuracy of their perceptions of the bighorn population. Over 90% of the survey respondents Most Least indicated they were aware of the existence of desert bighorn Favorable Favorable sheep in PRW. However, 67% had no information concerning the size of the population. Only 29% of those providing Policy N%N% estimates reported a size similar to tne 1979 estimates of 70 to 100 animals indicated by the Arizona Game and Fish Depart- ment. Nearly 60% of the respondents stated they had no infor- Voluntary Restrictions by Users in mation on the distribution of bighorns in PRW. Yet, the majori- Critical Bighorn Areas During ty of those who did offer their understanding of the distribu- Specific Seasons of the Year 25 30 3 4 tion appeared to be fairly well informed. Mandatory Restrictions of Users in Critical Bighorn Areas During Respondents demonstrated several interesting perceptions Specific Seasons of the Year 32 38 6 7 regarding the effects of recreational activities on the bighorn sheep. As illustrated in Table 1, the majority of respondents felt as if their activities in PRW had little, if any, effect on the Permit System That Would Limit sheep. Most of these individuals indicated they generally con- the Amount of Use Year-Round 17 20 33 39 fined their travel to the trails and conducted no disturbing ac- No Change in Existing Policy tivities in the area. Other justifications provided suggested (i.e. No Restrictions on they were not using bighorn habitat areas, bighorns are not Recreational Use) 6 7 42 50 afraid of people anyway, and that if they did not see the sheep, they could not possibly be affecting them. While it is possible Other 4500 to understand how beliefs such as these might exist, several of the previously mentioned humanlbighorn interaction studies have demonstrated that they are not necessarily true. were other frequently reported activities. Respondents also indicated that generally, they had no particularly favorite area in Of those individuals suggesting their activities did have an ef- PRW. A small percentage of the users sought areas in PRW fect on the sheep, most believed their presence in recreational (generally off-trail), where they felt they would have a greater use areas caused sheep to avoid those areas. Eleven percent chance of observing the animals. had no opinion regarding effects of their activities on bighorn sheep. The extended presence of a recreator in one particular area increases the probability they will cause somitype of impact(s) Although respondents generally believed they did not per- on the area. Cam~sitesare excellent exam~les.Res~ondents sonally affect sheep, 70% believed that recreational activities of the SAQ provided indications of the areas'which are current- of others certainly did affect bighorn. Over 30% of the ly most utilized for camping in bighorn habitat. Those results respondents indicated that bighorn hunting had an obvious indicate that several of the most popular campsites were negative effect on the population. Most of the individuals pro- located extremely close to wildlife water catchments. Extend- viding that response expressed opposition toward hunting ed use of those areas may be deterring wildlife, including bighorn sheep in PRW. Slightly less than 30 percent believed bighorn sheep, from using water during critical periods. In the combined effects of other people in PRW (apparently ex- order to predict locations that may be expected to receive cluding themselves) caused sheep to avoid areas. Other greater camping pressure than others, the components of a responses indicated hikers with dogs, cross-country travelers, perceived "good campsite" needed to be identified. Data in- people specifically attempting to obtain close observations of dicated that the 3 most important components were nearby the sheep, and large travel groups were likely to disturb water, a level area, and trees. Additionally, visitors used water bighorn. at seeps and springs near wildlife water catchments. Those who felt as if recreational activities of others had little effect on sheep primarily believed PRW received too little Value of Bighorn Sightings. The potential value of wildlife to human use to have any impacts. Other responses indicated the wilderness experience has been well described by beliefs that other people generally stay on trails and that Schoenfeld and Hendee (1978:33) "The fact that many people bighorns are probably habituated to human use. As before, are not deliberately seeking contact with wildlife makes little 11% had no opinion concerning the recreational effects of difference; the incidental contact--the chance observation others on the sheep. under natural conditions--can enrich immeasurably the many satisfactions that accrue to wilderness users from the overall Finally, respondents were given a hypothetical situation of a experience." Not only may direct wildlife encounters have declining bigh~rnpopulation in PRW and were asked to in- value to the wilderness user, but simply knowing that the dicate their preference regarding implementation of 1 of 4 possibility exists may be an important and beneficial part of possible courses of action concerning restrictions of recrea- one's wilderness experience. Users of PRW indicated thevalue tional use in PRW. Responses indicated a preference for of bighorn sheep sightings to their experience in a question mandatory restrictions of recreational use in specified bighorn regarding their most enjoyable types of wildlife encounters. All habitat areas during certain periods of the year (Table 2). The 10 of the telephone respondents that reported previous second most popular alternative was voluntary restriction. bighorn sightings felt as if they had experienced a rare occurrence and suggested those encounters were the most in- In an independent question pertaining to the above teresting of all previous wildlife encounters. Of those users, preferences, users indicated that the least appealing alter- 60% believed the sightings were the highlight of all past native was no change in current use policy. recreational experiences in PRW. Results appear to provide some indication of the overall value

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -3- of bighorn sheep to backcountry users in PRW. Although most leashed dogs produce maximal withdrawal responses in visitors are unable to directly experience the sheep, the "ex- bighorn sheep (MacArthur et al. 1979). Personal observations istence value" of the bighorns (as a vital component of PRW) in PRW indicated that many recreators are accompanied by appears to be strong enough for them to advocate restrictive their dogs while on backcountry excursions. Furthermore, few use measures for the welfare of the sheep. Other responses of the animals have been observed on leash. Due to the poten- (Table 2) indicated a permit system would be too restrictive. tial which this activity has for dramatically increasing stress on the sheep, the presence of dogs in backcountry areas of bighorn habitat should be discouraged. CONCLUSIONS AND MANAGEMENT RECOMMENDATIONS PRW user-education could be extremely useful for increasing Bighorn sheep are a unique and valuable resource. Unfor- awareness regarding needs of the bighorn sheep. Although tunately, the general trend over the past 100 years has been a most visitors are currently aware of the existence of desert reduction of sheep habitat in North America. Human use of bighorns in PRW, they are relatively uninformed of the size and bighorn habitat is expected to increase as outdoor recreation distribution of the population. Most importantly, users need to becomes more popular. Herein lies the problem and it will re- be made aware of the possible consequences of their ac- quire special management consideration to avoid detrimental tivities on sheep. This study indicates that backcountry users effects to bighorn sheep. The future well-being of a remnant believe their activities in PRW have little, if any, effect on the population of desert bighorn in PRW will require planning and sheep. Whereas this is yet to be fully determined, it is highly sound management of the herd and of the human uses of its possible that serious disturbances are taking place that will habitat. The results of this study should provide managers cause negative influences on the total population. Informa- with a basic understanding of the recreational uses and users tional signs placed in backcountry areas or distribution of of bighorn habitat in PRW, consequently laying a ground- short pamphlets could be utilized to provide users with a work for further investigarions concerning the physiologi- general knowledge of the population and information on callbehavioral effects of this use upon the sheep. measures which should be taken to ensure the well-being of the sheep. The information should be resented in a ~ositive The general pattern of recreational use in bighorn habitat in context 'and promote reduction of 'potentially disturbing PRW appears to be one of short lengths of stay by individuals recreational activities. The major emphasis of this information who primarily concentrate their activities around the major should be placed on discouraging the following activities: hiking trails. PRW users can be categorized in 2 ways: (1) lower (1) cross-country travel in backcountry areas, (2) camping near canyon users and (2) backcountry users. wildlife water catchments, and (3) traveling with dogs in back- The majority of PRW visitors use the lower canyons and have country regions. Backcountry users appear to be quite con- most frequently confined their activities to the lower reaches scientious and committed to the ideals of Wilderness, of the recreational areas, seldom penetrating more than 2 or 3 therefore, this suggested tool could be extremely valuable in miles (3.2-4.8 km) into the wilderness. Those individuals seem altering recreational activity patterns. Hendee and Burdge to desire the benefits of wilderness recreation without exert- (1974) provide further support for this proposal by maintaining ing much physical effort in doing so. The intensities of recrea- that wildlife harassment can be reduced if recreators under- tional activities in most lower canyons over the past years stand the impact of their activities and are offered alternatives have probably precluded bighorn sheep use of these areas. In that satisfy their needs without causing stress to wildlife. addition, given the demand for these activities from the grow- Two types of social values seem to pervade the manner in ing Tucson area, they would most likely be quite difficult to which users of PRW perceive the resources of the area. The control. From a practical standpoint then, efforts to protect first would be that which is formulated through direct ex- the bighorn sheep from recreational impacts should focus on periences with wilderness attributes. Examples of these pro- the uses of the backcountry areas. vided by users are geological formations, vegetation, and wildlife. The value of bighorn sheep to PRW visitors is not Activities of backcountry users would appear to pose the derived as much from this type of formulation as it is that of greatest threats to bighorn. Those users travel greater the second type--an existence value. Although users seldom distances into PRW, often stay for longer periods of time, experience direct encounters with desert bighorn, they never- utilize more of the resources, and generally have a greater theless indicate the value of their existence as a vital com- chance of encountering and disturbing bighorn sheep. Results ponent of PRW by demonstrating a willingness to comply with of this study indicated few humanlbighorn encounters occur- mandatory use restrictions in areas critical to the sheep. red in PRW. However, the number of human disturbances is The long-term future of desert bighorn in PRW is by no means likely to be much greater than r+orts would indicate. Unfor- secure. Until a better understanding of the biological tunately, the effects of indirect eiwounters in PRW have not parameters of the population is obtained and the effects of in- been determined. Behavior of bighorn sheep towards humans creasing human use of its habitat can be determined, manage- appears to be a reflection of the way humans behave towards ment should take basic precautions against recreational sheep. If disturbances continue, sheep may completely aban- overuse of sheep habitat. At this time, stringent restrictive use don habitat near recreational areas. Bighorns may then face measures do not appear appropriate. However, the following overcrowded conditions, which most frequently lead to recommendations are made as safeguards against stressful situations, paving the way for disease and death humanlbighorn sheep conflicts in PRW: (DeForge 1976). 1. Continue to monitor trail traffic in lower Pima Canyon Cross-country travel in bighorn habitat and backcountry camp- with the existing lower traffic counter in order to obtain ing at or near wildlife water catchments are 2 activities long-term indications of total canyon use. threatening the habitat of bighorns. For the welfare of the sheep, such activities should be discouraged, especially dur- 2. Provide backcountry users of bighorn habitat (especial- ing critical periods such as lambing season and drier months ly in Pima Canyon) with information that is designed to of the year. increase users' level of knowledge of bighorn sheep in PRW. This is perhaps best accomplished by locating in- Another potentially harmful activity worthy of special con- formational signs'near backcountry trails which are de- sideration is that of backcountry travel with dogs. Previous signed to make visitors aware of the possible conse- studies have demonstrated that humans accompanied by quences of activities in bighorn habitat in addition to

-4- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS deterring the following specific backcountry activities: (i) backcountry travel with dogs TRANSFERRINS OF (ii) cross-country travel (iii) camping within l/4 mile (402 m) of wildlife water DESERT BIGHORN IN catchments. ARIZONA, NEVADA, Enforce existing regulations against camping within lh mile (402 m) of wildlife water catchments, especially AND UTAH in Pima Canyon, by using a site-specific informational signs andlor alteration of nearby camp sites with natural materials (e.g. large rocks) to a degree that is unappealing to users. Provide no improvements of backcountry trails in Pima Thomas D. Bunch Canyon in order to maintain low volumes of backcountry Dept. of Animal, Diary and Veterinary Sciences use. Utah State University Obtain accurate PRW bighorn population data including Logan, UT numbers, health, productivity, lambing areas, distribu- Paul Webb tion, resource utilization, and seasonal movements. Arizona Game and Fish Department Use information from recommendation 5 as data base Phoenix, AZ for monitoring the physiological and behavioral effects of recreational use on bighorn sheep in PRW. J. Juan Spillett Dept. of Wildlife and Fisheries Sciences LITERATURE CITED Texas A & M University College Station, TX Bryan, R.B. and M.C. Jansson. 1973. Perception of wildlife hazard in national park use. In J.C. Hendee and C.A. Schoenfeld, eds. Human dimensions in wildlife programs. Abstract: Transferrin phenotypes and allelic frequencies Wildl. Mgt. Inst. Washington, D.C., pp. 129-142. were established for 120 desert bighorn (Ovis canadensis) DeForge, J.R. 1976. Stress: Is it limiting bighorn? DBC from wild populations in Arizona, Nevada, and Utah. Transfer- Trans. 27-29. rins DE and EE were observed in animals from Arizona, EE in . 1980. Ecology, behavior, and population dy- bighorns from Nevada and DD, DE, and EE in Utah specimens. namics of desert bighorn sheep, Ovis canadensis nelsoni, Significant differences between the desert bighorn of Nevada in the San Gabriel Mountains of California. M.S. thesis, and Utah in the D and E allelic frequencies were observed. The California St. Polytechnic Univ. Pomona, CA, 133 pp. frequency of the E allele in desert bighorn from Arizona was closer to that of the Nevada sheep. Differences in transferrin Elder, J.M. 1977. Human interactions with Sierra Nevada big- type and allelic frequency are believed to reflect geographical horn sheep: the Mt. Baxter herd. M.S. thesis, Univ. Michi- isolation. gan, Ann Arbor, MI, 93 pp. Geist, V. 1971. Mountain sheep: A study in behavior and evolution. The Univ. of Chicago Press, Chicago, IL, 383 pp. Transferrins (Tf) are the iron-binding globulin which form part of the Beta-globulin fraction of serum proteins. This protein Graham, H. 1971. Environmental analysis procedures for big- occurs in various molecular forms (polymorphic) and exhibits horn in the San Gabriel Mountains. DBC Trans. 38-45. multiple band patterns on stained' starch gel after elec- Hendee, J.C. and R.J. Burdge. 1974. The substitutability con- trophoresis. cept: implications for recreation research and management. J. Leis. Res. 6:157-162. In domestic sheep, 9 codominant Tf alleles (I,A,G,B,C,D,M,E, and P) genetically control 2 electrophoretically separable pro- , G.H. Stankey and R.C. Lucas. 1978. Wilderness tein fractions or a "zone pair", and produce an array of Tf Management, US. Govt. Print. Off. Misc. Publ. No. 1365, phenotypes (Osterlee et al., 1967; Stormont et al., 1968). Three Washington, D.C., 381 pp. additional alleles (A+ B+ and E-) have been identified in Hicks, L.L. 1977. Human disturbance of the Mt. Baxter herd wild sheep (Lay et al., 1971; Valdez et al., 1978). of Sierra Nevada bighorn sheep. M.S. thesis, Univ. Michi- gan, Ann Arbor, MI, 57 pp. Comparisons of allelic frequencies have been useful in characterizing certain genotypes of wild sheep. Lay et al. Light, J.T. Jr. and R. Weaver. 1973. Report on bighorn sheep (1971) observed that the D allele occurred at a much higher fre- habitat study in the areas for which an application was quency in populations of urial (Ovis vignei) in northeastern made to expand the Mt. Baldy winter sports facility. Cajon Iran, whereas the A allele was more prevalent in northwestern Ranger District, San Bernardino Natl. Forest, USFS, 39pp. populations of Armenian sheep (0. orientalis). Bunch et al. MacArthur, R.A., R.H. Johnston, and V. Geist. 1979. Factors (1974) and Spillett et al. (1975) observed only Tf EE in Nelson influencing heart rate in free-ranging bighorn sheep: a desert bighorn (0.c. nelsoni) of Nevada, while the same race in physiological approach to the study of wildlife har- Utah maintained Tfs DD, DE and EE. rassment. Can. J. Zool. 57(10):2010-2021. In this report we further describe transferrin phenotypes for Nelson, M. 1966. Problems of recreational use of game ranges. desert bighorn in Arizona, Nevada and Utah and compare the DBC Trans. 13-20. allelic frequencies between the bighorn populations in these Purdy, K.G. and W.W. Shaw. 1980. Recreational use of desert states. bighorn habitat in Pusch Ridge Wilderness. DBC Trans., pp. 52-56. MATERIALS AND METHODS Russo, J.P. 1956. The desert bighorn sheep in Arizona. Blood samples from 120 desert bighorn sheep were drawn Wildl. Bull. NO. 1. Ariz. Game & Fish, Phoenix, AZ, 153 pp. from the jugular vein of captured animals using sterile techni- Schoenfeld, C.A. and J.C. Hendee. 1978. Wildlife management ques. Serum was then obtained from clotted biood and stored in wilderness. Wildl. Mgt. Inst. Washington, D.C., 172 pp. at - 20°C. Horizontal starch-gel electrophoresis was used to

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -5- Table 1. Transferrin phenotypes and allelic frequencies in desert bighorn from Utah, Arizona and Nevada.

No. of Animals Locality Subspecies Tf Phenotype Allelic Frequency

26 Utah 0.c. nelsoni Arizona 20 Black Mountains O.C. nelsoni 6 Plomosa Mountains 0.c. mexicana 3 Harquahala Mountains 0.c. mexicana 25 Kofa Mountains 0.c. mexicana 43 Nevada 0.c. nelsoni

identify transferrin phenotypes. Eight sera were run We can not presently explain why Tf DD is absent in Arizona simultaneously in each gel and compared to reference sera ex- desert bighorn populations. Random assortment of alleles hibiting Tf DE. ~eo~ra~hicorigin of 'bighorn sampled is shown would be expected to result in bighorn homozygous for the D in Table 1. allele, unless there is strong selection against this cornbina- tion. Investigations have indicated some association between RESULTS AND DISCUSSION transferrin types and reproductive performance in domestic Transferrins DE and EE were observed in desert bighorn from livestock. The reduction in reproductive rate is usually small Arizona, Tf EE in Nevada sheep, and Tfs DD, DE and EE in Utah (Fesus and Rasmusen, 1971a and b, Rasmusen and Tucker animals (Table 1). Allelic frequencies of Nevada and Utah 1973; Spooner, 1974) however, in local populations specific desert bighorn differed markedly. Only the E allele was observ- associations may result in a high reproductive impairment (Im- ed in Nevada's desert bighorn sheep, whereas in Utah's desert lah, 1970). The same adverse effects may occur in small, highly bighorn sheep the E allele occurred at a frequency of 0.17. inbred populations of desert bighorn sheep and may account Allelic frequencies in desert bighorn from Arizona ranged be- for the high frequency of occurrence of specific transferrin tween the values established for Nevada and Utah ar~imals. phenotypes. Allelic frequencies did not differ significantly among popula- LITERATURE CITED tions of Arizona bighorn. However, the occurrence of Tf EE was higher in sheep from the Black Mountains, with the allelic Bunch, T.D., W.C. Foote and J.J. Spillett. 1974. Transferrins of frequency (0.88) being closer to the value observed in bighorns two populations of Nelson's desert bighorn (Ovis from Nevada. canadensis nelsoni). DBC Trans. 38-39. Fesus, L. and B.A. Rasmusen. 1971a. The distribution of Although the selective advantages of transferrin polymor- transferrin and hemoglobin types in families of Suffolk phism in desert bighorn remain unknown, the value of transfer- and Targhee sheep. Anim. Blood Grps. Biochem. Genet. rins as genetic markers can be used to separate Nevada's 2~39-43. desert bighorns from Utah's population of desert bighorn. . 1971b. Transferrin types and litter size in These differences most likely reflect the geographical isola- the pig. Anim. Blood Grps. Biochern. Genet. 257-58. tion of these 2 populations of sheep. Arizona populations of Imlah, P. 1970. Evidence for the Tf locus being associated with desert bighorn comprise 2 taxa: (Ox. nelsoni and 0.c. mex- an early lethal factor in a strain of pigs. Anim. Blood Grps. icana). The higher frequency of occurrence of the E allele in Biochem. Genet. 1:5-13. desert bighorn endemic to the Black Mountains may indicate a Lay, D.M., C.F. Nadler and J.D. Hassinger. 1971. The fairly close phylogenetic relatibnship to desert bighorn sheep transferrins and hemoglobins of wild Iranian sheep (Ovis in Nevada. linnaeus). Cornp. Biochem. Physiol. 40B:521-529.

Osterlee, C.C. and J. Bouw. 1967. Nomenclature of transferrin types in sheep. Immunogenet. Letter. 5:lO-12. Rasmusen, B.A. and E.M. Tucker. 1973. Transferrin types and reproduction in sheep. Anim. Blood Grps. Biochem. Genet. 4:207-220. Spooner, R.L. 1974. The relationships between marker genes and production characters in cattle, sheep and pigs. First World Cong. Genet. Applied Livestock Production, Madrid. Vol. 1, 267-271. Storrnont, C., Y. Suzuki, G.E. Bradford and P. King. 1968. A survey of hemoglobins, transferrins and certain red cell antigens in nine breeds of sheep. Genetics. 60:363-371. Spillett, J.J., W.C. Foote and T.D. Bunch. 1975. Chromosome and blood analyses of wild and domestic sheep. DBC Trans. 46-50. Valdez, R., C.F. Nadler and T.D. Bunch. 1980. Evolution of wild sheep in Iran. Evolution 56-72.

-6- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS I lands as Forest Reserves. The first Forest Reserves in Nevada HISTORY OF BIGHORN were designated in 1904; however, it wasn't until 1919 that all of the 2.5 million acres that were to make up the present Hurn- TRANSPLANTS ON THE boldt National Forest were so designated. By 1910 the nomadic bands of domestic sheep were removed, the grazing HUMBOLDT NATIONAL conflicts between ranchers resolved and grazing allotment boundaries established. FOREST - PART I Domestic sheep and cattle numbers for 2 Ranger Districts, Mt. City and Jarbidge, encompassing 765,718 acres are:

Domestic Warren E. Kelly Sheep Cattle Humboldt National Forest Elko, NV 89801

l NTRODUCTION Historically the Humboldt National Forest had three races or subspecies of bighorn sheep (McQuivey, 1978; Monson and In 1980 Humboldt National Forest grazed 54,000 cattle and Sumner, 1980). The California subspecies was found in the 79,500 domestic sheep and provided 240,000 animal unit Santa Rosa Mountains; the Rocky Mountain subspecies oc- months of use. In addition to domestic livestock, there were cupied the Ruby, Independence, Jarbidge, Ward, Snake, Mt. 34,500 mule deer, 350 elk, 140 bighorn and 380 antelope utiliz- Moriah, and Schell Mountain Ranges. The desert bighorn were ing the forest. found in the White Pine and Quinn Ranges. Bighorn were probably the most numerous large wild ruminant in this area in Along with reductions in livestock numbers, grazing systems the late 19th century. By the mid-1930's both the Rocky Moun- were put into practice and seasons of use were changed. Many tain and California bighorn had been eliminated from the range improvements such as water developments and forest. reseeding projects were accomplished. Ranges slowly began to show improvement; both soil and vegetation were beginning EARLY GRAZING PRACTICES an upward trend and higher value plants were on the increase. From 1889 to 1905 many bands of nomadic domestic sheep RESTOCKING WILD SHEEP roamed over the state. The best estimate we have today is that With range conditions improving and domestic sheep numbers about 2.5 million sheep grazed through the valleys and moun- decreasing, thoughts could be turned to restocking ranges tains in their annual movements. These nomadic bands of with wild sheep. Some of these thoughts came on us a little sheep competed with the livestock or resident ranchers. This too fast. Between Christmas and New Year's Day of 1974, the was a prime example of the sheepman-cattleman conflict in Department of Fish and Game informed us that personnel of the west. Fortunately it didn't turn into a shooting war. Stories the state of Wyoming were trapping Rocky Mountain bighorn were told how sheep herders would actually race each other to and were expected to have animals on their way to Nevada in be the first to get to the best forage areas and campsites in the the first week of January. This presented several slight higher mountains. This management practice caused an enor- problems: mous amount of trampling, accompanied by severe grazing, 1. Since the the passage of the National Environmental which left the county a dust bowl. Owners of these sheep, hav- Policy Act in 1969 (NEPA) each Federal action must ing no ranch and property, moved their animals north in the have an environmental analysis and an environmen- spring and back south for the winter. Under these manage- tal assessment report written, to determine if an ment conditions livestock were on the range too early in the Environmental Impact Statement was necessary. spring and stayed too late in the fall. Many plants were heavily 2. An environmental assessment for the introduction or grazed prior to seed ripe and severely grazed during summer reintroduction of any wildlife species (FSM 2640.41) on and fall, further reducing plant vigor. These grazing practices any national forest must be approved by the Regional resulted in changes in plant composition and succession. Forester. Many native grasses of high forage value nearly disappeared 3. It takes a minimum of 4-6 weeks to do the environ- and were replaced with lower quality grasses of less palatabili- ty and nourishment. Cheat grass (Bromus tectorum) often mental analysis, write the environmental assessment and get the document reviewed by District referred to as bronco grass by early day ranchers, began to in- Rangers, Wildlife Staff, For~stSupervisor and vade many of these over-used ranges, further creating pro- approved by the Regional Forestw. blems of plant competition and causing severe fire hazards. Large range fires that would burn for weeks were common. 4. The Forest Service had less than 2 weeks to complete the analysis, write the report and From 1905-1920 bighorn populations were either drastically have it approved. reduced or completely eliminated, largely due to competition for food, water and space, and from diseases and parasites The environmental assessment was written and approved. The carried by their domestic cousins (Kelly, 1979). A report by the Rocky Mountain bighorn were released on the forest. This en- first Forest Supervisor of the Humboldt National Forest stated tire operation emphasized the need for transplanting that bighorn were common in the Ruby Mountains from guidelines to cover these situations. 1908-1910 (Tremewan, 1964). The last Rocky Mt. bighorn was NEW GUIDELINES observed in 1921. Mr. Hugh Martin reported large numbers of bighorn on Tennessee Mountain and in Copper Basin in 1889 While this environmental assessment was being written, new (Martin, 1964). The California bighorn was last observed in the guidelines w6re being formulated between the Nevada Dept. of Santa Rosa Mtns. in the mid-1930's. Fish & Game (NDFG) and the Forest Service (FS). Because of these nomadic bands of domestic sheep, resident In January 1975 a Memorandum of Understanding between the ranchers petitioned President Roosevelt to designate certain FS and the NDFG was approved by the Director and the

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -7- Regional Forester. In the appendix of the memorandum (FSM any transplants of wildlife it plans to initiate on lands 2611.1-33) were specific policies and guidelines that were to under its administration. be followed relative to introductions and reintroductions of Following these directions in the memorandum the FS com- wildlife. They are as follows: pleted 2 environmental assessments for the reintroduc- 1. Applications to introduce native or exotic species of tion of California bighorn sheep into 2 areas of the forest. The fish (those species that do not or have not existed preparation of these 2 EA's took considerable time during the within the continental U.S. within recorded historical field season, especially time that hadn't been considered in times) and wildlife on national forest lands will be our project work planning. At our next interagency meeting, made in writing to the concerned Forest Supervisor. the Director and the Forest Supervisor agreed that the agency Applications will be made far enough in advance proposing the introduction of any wildlife species would be (preferably 6 months to 1 year) so the FS will responsible for preparing the environmental assessment. have sufficient lead time to properly evaluate the impact on other uses and resources. RESULTS 2. Proposed introduction sites will be jointly examined by FS and Fish & Game Dept. representatives during In the summer of 1977 the Department requested that bighorn the field season following receipt of the application. be released into the Snake Range on the Ely Ranger District. Mike Wickersham of the Department prepared the draft of the 3. For desirable introductidns, FS and Fish and Game EA. I reviewed it and made the necessary changes to conform Dept. personnel will jointly prepare a brief plan with FS policy, had it reviewed by our staff and the District of management,.Such a plan will provide for manage- Ranger, revised it and sent it to the Regional Office for ap- ment of habitat and will maintain satisfactory proval. Since then the Department has made 2 releases of forage, soil, and other resource conditions. The plan Rocky Mountain bighorn into this area. will be submitted to the Regional Forester and the Director for approval. To date, 4 areas of the forest have approved environmental 4. For fish and wildlife introduction proposals considered assessments for the reintroduction of bighorn sheep. One or undesirable by the FS, the Forest Supervisor will more releases have been made into each area. A total of 74 recommend disapproval to the Regional Forester who animals has been released on the forest, 26 California bighorn will advise the Director in writing, giving the and 48 Rocky Mountain sheep. Last year's population reasons for disapproval. estimates indicated an increase to 33 California bighorn and 72 Rocky Mountain bighorn. 5. The transplanting or mtroduction of big game animals or other species considered exotic to the area must Due to problems encountered, the release of California be approved by the Regional Forester. Each approved bighorn into the Jarbidge Wilderness area was possibly the transplant will be covered by a separate cooperative most frustrating, yet most gratifying experience a Wildlife agreement if deemed necessary. Biologist could have. When the Environmental Assessment 6. Forest Supervisor will be advised well in advance by was prepared local ranchers protested the reintroduction. the Department of the specific site and date of Several contacts were made by the District Ranger, Forest approved introductions including the number, sex, Wildlife Biologist and a Fish and Game Biologist. We found conditions, and other pertinent information. out that if the sheep were released in the wilderness areas, the 7. The Department will be responsible for securing ad- ranchers would withdraw their protest. Both the Department vance concurrence of landowners and other land and the FS agreed to this. There is a primitive road to the edge management agencies in areas affected by recom- of the wilderness--however, it is not passable in winter. The mended transplants. It will also be responsible for the other alternative was to move the sheep by helicopter to the neck-banding and/or ear-tagging of all game animals release site. transplanted to approved sites and for furnishing Everything seemed to come together at the same time. The reasonable assurance that they are free of infectious North American Wild Sheep Foundation gave the ldaho Dept. disease. of Fish & Game funding for the capture operation. The Hum- 8. During the project planning stages, the Forest Service boldt National Forest got sufficient funding for helicopter ren- will inform the Department and secure concurrence in tal and the sheep were transplanted to the release site.

Table 1. Numbers of bighorn released in each area.

Date EA Date of Current Origin Area Completed Release Rams Ewes Lambs Population of Bighorn

Mt. Moriah Jan. 1975 Jan. 1975 5 11 35 Wyoming ~antaRosa Oct. 1975 Mar. 1978 2 7 3 21 British Col. Snake Range Aug. 1977 May 1979 2 6 10 Colorado Snake Range Aug. 1977 Mar. 1980 3 9 12 Colorado Mt. Moriah Jan. 1975 Jan.1981 5 10 15 Wyoming Jarbidge Oct. 1975 Feb. 1981 1 4 2 Idaho Jarbidge Oct. 1975 Mar. 1981 - 6 * 1 12 Idaho *Two mortalities occurred in the transplanting operation

-8- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS I'm not sure we can label any of these bighorn reintroductions as successful at this time, however, the animals have ap- STATUS AND peared to adjust to their new habitat and reproduction has stayed ahead of mortalities. Another four to five years should DISTRIBUTION OF give us this answer. SUMMARY BARBARY SHEEP Bighorn populations began to decline in the early 1900's and both the Rocky Mountain and California races of bighorn IN THE SOUTHWEST became extinct from the Forest by the mid-1930's. The cause of this die-off was attributed to habitat alteration and to the UNITED STATES disease and parasites carried by domestic sheep. The reestablishment of bighorn populations into their historic ranges on the Humboldt National Forest began in January of 1975 when 16 Rocky Mountain bighorn from Wyoming were released into the Smith Creek Drainage of Mount Moriah. C. David Simpson and Leslie J. Krysl When this release took place the Memorandum of Understand- Dept. of Range and Wildlife Management ing between the Department and the FS had just been approv- Texas Tech University ed by the Director and the Regional Forester. The Memoran- dum outlined guidelines each agency was to follow for the introduction or reintroduction of wildlife populations. Using Abstract. Dispersal of Barbary sheep (Ammotragus lervia) these guidelines 3 environmental assessments have been from accidental or intentional release sites has resulted in the prepared. All 3 of these areas now have populations of successful establishment of free-ranging populations in the bighorn. southwestern United States totalling about 6500 animals. The distributions of these free-ranging populations in 1980 are Although we had communication problems, no one lost sight that the most important objective was to get bighorn back into mapped for Texas and New Mexico, based on confirmed, their historic ranges. isolated sightings away from release sites. Dispersal routes and mechanisms are related to topograpohic and habitat LITERATURE CITED selection. The magnitude of Barbary sheep dispersal, their Kelly, W. E. 1979. A comparison of three bighorn areas on the preference for traditional desert bighorn sheep (Ovis canaden- Humboldt National Forest. DBC Trans.,pp. 37-39. sis) habitats, and the absence of control techniques for this Martin, H. 1963. Eyewitness account of early day wildlife species represent serious concerns of desert bighorn biologists. This paper examines the present status and pro- occurrences and range appearance in the Gold Creek area. Unpubl. rept. USFS files, 4 pp. gressive dispersal of Barbary sheep so that managers can develop combative strategies to prevent further incursions in- McQuivey, R.P. 1978. The desert bighorn sheep of Nevada, to desert bighorn range. Biological Bulletin No. 6, Nev. Dept. of Fish &Game, 81pp. Monson, G. and L. Sumner. 1980. The desert bighorn, its life INTRODUCTION history, ecology and management. Univ. of Ariz. Press, 370 pp. The Barbary sheep has been shown to present a very real Tremewan, S. 1964. Early day range, livestock and wildlife threat to the already beleaguered desert bighorn (Barrett 1967, observations. Unpub. rpt, USFS files, 12 pp. Simpson et al. 1978, Seegmiller and Simpson 1979). Each year , brings more data to the fore on the spread of Barbary sheep in- ' USDA-Forest Service. Title 2600-Wildlife and fish manage- to remaining habitats occupied by desert bighorn, emphasiz- ment. Memorandum of Understanding, Forest Service1 ing the urgency of research into control and management of Nev. Dept. of Fish & Game. Sec. 2611.1-25 to 2611.1-37. the former species. Recent confirmed sightings of a small remnant herd of desert bighorn in the Guadalupe Mountains, from where this species was previously thought to have been extripated, is a case in point. Relatively little attention has been paid to the southward spread of Barbary sheep from the Hondo Valley, New Mexico, prior to these sightings. Attempts to clear the southern Guadalupe range of Barbary sheep subsequent to the reappearance of desert bighorn in this area met with no success, despite considerable agency effort and expenditure. This situation served to emphasiza further the need to monitor carefully and, if possible, limit Barbary sheep dispersal and establishment until mansgement method- ologies can be developed to control this exotic. Research on free-ranging Barbary sheep to date has resulted in an accumulation of basic biological data on this species. At a recent symposium on its ecology and management (Simpson 1980), 25 presentations covered federal and state agency policies toward Barbary sheep, systematics, historical reviews, habitat use, dispersal and home range, food habits and competition with endemic ungulates, behavior, and diseases. One paper addressed the status and distribution of free-ranging Barbary sheep in Mexico (Rangel and Simpson 1980) and discussed dispersal from escape sites. However, nowhere in the literature since Ogren (1965) is there any status and distributional information for this species in the southwestern United States. This paper documents recent

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -9- dispersals of free-ranging Barbary sheep from original release counties in west and central Texas. These data were cor- sites and evaluates dispersal trends as they threaten further related with information in a similar survey conducted by incursion into desert bighorn sheep populations. TP&W (Harmel 1980) and records on our personal files, then mapped to show distribution of Barbary sheep in Texas. ACKNOWLEDGEMENTS Data on Barbary sheep distribution in New Mexico has been We wish to thank members of the Exotic Ungulates Committee collected since 1978 as part of the efforts of the Exotic of the Desert Bighorn Council for their support and input. Ungulates Committee of the Desert Bighorn Council. District Special appreciation is expressed to the USDA Soil Conserva- and state level personnel from all agencies in the state were tion Service (SCS) in Texas who kindly conducted a county- contacted during 1978-79 for their input to this study. All loca- level survey of free-ranging Barbary sheep in that state, the tions were verified upon receipt whenever possible through the Texas Department of Parks and Wildlife (TP&W), and the New agencies responsible for land management where the sighting Mexico Department of Game and Fish (NMGF) for access to was recorded. Confirmed locations were plotted on large-scale data from their recent surveys. Various other federal and state maps of New Mexico; if 5 independent herd sightings were agency personnel also have supplied important information on recorded in a local area, that area was considered to have a new sightings and dispersal areas throughout the Barbary resident population. sheep range; we thank each of these contributors for their continued interest in documenting the spread of Barbary sheep In 1980, NMGF surveyed various agencies and private land- across ranges in the Southwest. owners to update their data on distribution and densities of Barbary sheep throughout the state (Morrison pers. comm.). METHODS Data from this survey were incorporated with previously Published literature, agency reports and individual knowledge documented locations and plotted to show Barbary sheep were used by the Council's Exotic Ungulates Committee to distribution in New Mexico in 1980. establish locations of known Barbary sheep release sites in lnformation on the Californian Barbary sheep population was the southwestern .United States. These release sites were obtained from Barrett (1966, 1980) and Johnston (1980). Barrett documented and mapped, along with data on numbers, sex, (pers. cornm.) also suggested factors which regulated Barbary and ages of animals released where these were known. Loca- sheep dispersal in California. tions of captive herds (behind game-proof fencing) were also established against future escapes to the wild by confined RESULTS animals. History of Introduction. All the known introductions (both in- In addition, the SCS in Texas circulated a questionnaire to 13 tentional and accidental) of Barbary sheep in the administrative Area Offices thought to have Barbary sheep in southwestern U.S. into the wild were evaluated and are their district. lnformation was requested on both confined and documented by states (Table 1). Detailed sex and age data on free-ranging animals, escapes, locations, quantitative data on released animals are shown where these could be established. sex and ages of first sighting animals, and habitat information Numbers are not known for escaped animals but, with the ex- for each county. All Area Offices responded fully, covering 139 ception of 2 major escapes recorded in the Hondo Valley of

Table 1. Known introductions of Barbary sheep to the wild in Texas, New Mexico and California with population estimates for 1980.

Adult Adult Juveniles 1980 State and Locality Date Males Females (Males and Females) Total Source Estimate

TEXAS: 3,750 Palo Duro Canyon (R) 1957 8 13 (10) Jackson 1951 Palo Duro Canyon (R) 1958 4 9 -- Wallace 1959 Trans-Pecos Region (R) 1960's unknown unknown unknown Decker 1978 Edwards Plateau (E) 1960's unknown unknown unknown SCS survey 1980 NEW MEXICO: 2,500

Canadian River (R) 1950 4 8 0 0 Morrison 1980 Canadian River (R) 1950 14 20 5 6 Morrison 1980 Canyon Largo (R) 1956 unknown unknown unknown unknown Morrison 1980 Hondo Valley (E) Various unknown unknown unknown unknown Dickinsons & Simpson 1980* CALIFORNIA: 250 Hearst Ranch (E) 1953 unknown unknown unknown unknown Barrett 1980 COLORADO: (D) 0-10 OKLAHOMA: (D) 25-40 ARIZONA 0

TOTAL

R5 released animals; E5 escaped animals; d5 dispersed animals 'Revised estimate based on further discussion with Joe McKnight, rancher in Hondo Valley, New Mexico.

-10- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS Mew Mexico, most escapes were considered to have been Establishment and Dispersal. Released and escaped limited to only a few head. animals in Texas have established free-ranging populations Five releases were recorded in Texas, the most successful be- over the Panhandle, the Rolling Plains, and the Trans-Pecos ing the 2 TP&W releases in Palo Duro Canyon (Jackson 1964, regions (Fig. 1). Growth and dispersal of the Palo Duro Can- Simpson et al. 1978). Three other releases were made by yon population has been discussed by Simpson et al. (1978). private landowners in the Trans-Pecos but details of these Recent sightings on a ranch in Oklahoma about 20 miles north were not recorded (Fig. 1). Four escapes were recorded for the of the Red River gorge (Johnson pers. comm.) probably Edwards Plateau and 1 for the Rolling, Plains (Table 2) resulting resulted from dispersals out of Palo Duro Canyon. Dispersal in establishment of 2 small free-ranging populations (Arm- from escape sites in the Edwards Plateau and Rolling Plains strong, pers. comm.; Kilpatrick, pers. comm.). seem to have been minimal, perhaps because of dense human settlement and development or due to the fact that Barbary In New Mexico, NMGF made 2 releases in the Canadian River sheep are not a protected game animal in that area and can be drainage, and 1 unauthorized release in the Canyon Largo area harvested year-round. Sheep from the 3 release sites in the

Figure 1. Distribution of Barbary sheep in Texas in Confirmed sightings 1980 compiled from various sources. Arrows 0 Confined herds indicate major dispersal directions based on frequency of sightings. + Release sites

(Ogren 1965, Morrison 1980), all of which have resulted in suc- Trans-Pecos have dispersed widely through most of the moun- cessful population establishment (Fig. 2). Animals are known tain ranges in that region. This semi-arid terrain wifh low to have escaped at various times from an enclosure in the Hon- human populations is climatically and vegetationally similar do Valley, giving rise to the free-ranging Barbary sheep popula- to their native north African habitat. The estimate of about tion in that area of the state (Dickinson and Simpson 1980a, 3,750 free-ranging Barbary sheep in Texas obtained during the Morrison 1980). SCS survey agreed closely with the 3,709 figure given by Arm- In California, the remnants of the Hearst Castle Barbary sheep strong (1979). collection escaped when the estate was neglected in the early Five free-ranging populations are permanently established in 1950's (Barrett 1966). Since that time the species has become New Mexico, 2 of which did not result from deliberate releases established successfully in the surrounding county (Barrett (Fig. 2). The population established in the southern Guadalupe 1980). Mountains clearly had its origins in the Hondo Valley herd

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -11- (Dickinson and Simpson 1980a). The herd north of the Grants Factors Influencing Dispersal. Dispersal outward from oc- area apparently resulted from long-range dispersal, but cupied range was initiated by rams, followed later by ewes and whether the origin was the Canadian River herd or down the lambs (Dickinson and Simpson 1980a). Analysis of the SCS Continental Divide from Canyon Largo animals is unknown. survey question on sex and age of first sightings of Barbary There were approximately 2,500 free-ranging Barbary sheep in sheep in an area had 22 respondents, 21 of which indicated New Mexico in 1980 by calculations obtained from our data, adult rams were seen on these occasions. Only 3 of 22 first which agrees with the recent NMGF survey findings (Morrison sightings were of ewes accompanying adult rams or of a lone pers. comm). ewe. These data, in addition to the recent lone ram sighting in Dispersal away from the Canadian River drainage has occur- western New Mexico where no Barbary sheep had been record- red in most directions, but the greatest movement appears to ed previously, substantiated Dickinson and Simpson's (1980a) have been to the north and the west as indicated by the arrows findings. in Figure 2. Three separate records of Barbary sheep in Barbary sheep appear to exhibit a broad habitat plasticity in southern Colorado in the early 1960's probably were due to their distribution. They have been reported as successfully northern dispersals from the Canadian release. No recent established in Post Oak Savannah (Solbert 1980), the Edwards sightings have been obtained from Colorado so presumably Plateau vegetation type (Ramsey and Anderegg 1972), the Roll- there are no free-ranging populations established in that state. ing Plains (Simpson et al. 1978, Gray 1980), in the semi-arid The Hondo Valley herd has moved northward into the Jecarilla Canadian River drainage (Ogren 1965), and in the arid moun- and Capitan mountains but the majority of movements have tains of the Chihuahuan Desert (Dickinson and Simpson 1979, been northeast, west and south through the Sacramento and 1980b, Rangel and Simpson 1980). They also are successfully Guadalupe ranges. This latter movement undoubtedly resulted established in the Pinyon-Juniper vegetation typical of the in arrival of Barbary sheep in the important stronghold of southern foothills of the Rocky Mountains in Canyon Largo desert bighorn, the San Andres range. The Canyon Largo in- (Bird and Upham 1980). Johnston (1980) reported on habitats troduction has expanded 'its range onto the adjacent public used by Barbary sheep in California, demonstrating the lands (Bird and Upham 1980), but no confirmed records are species' plasticity, but adding little to the Barbary available of long-range dispersal from this area. This may be sheepldesert bighorn sheep interface under discussion here. due to the dense vegetation of the area and lack of suitable However, if population growth and dispersal are indicative of dispersal corridors away from the present range. A recent preferred vegetative conditons, there is little doubt that the sighting (1979) of a Barbary ram north of Glenwood in the San semi-arid and arid conditons of Palo Duro Canyon, the Trans- Francisco River drainage represents a new dispersal record of Pecos and southeastern New Mexico are optimal habitat for almost 200 miles from the nearest known release site (Gregory Barbary sheep. pers. comm.). Barrett (1980) reported that although Barbary sheep numbers Only 1 srudy has been made of Barbary sheep vegetation type increased in California following the escape in 1953, the selection in traditional desert bighorn range. Dickinson and population probably peaked in the mid-1960's at about 320 and Simpson (1979) showed that of 12 vegetative series equally then declined to the present relatively stable population level available to Barbary sheep in the Guadalupe Mountains, only 2 of 160 head. Dispersal of up to almost 40 miles has been series were documented as used by sheep. All sightings made recorded for this population (Barrett 1980), but the general in this study fell in the Southwestern Desert Scrub formation range of the species has remained within 10 miles of the (USFS vegetative series maps), with 83.3% occurring in the original release site. SD 9 (Sotol-Ocotillo-Lechequilla) series, and the remaining 16.7% were in the SD 15 (Mariola-Goldeneye-Yucca) series. The collective total of all these introductions probably Dickinson and Simpson (1979) concluded that the total numbered approximately 400 animals. Over 1,000 animals have absence of Barbary sheep sightings in the other available been taken by hunters in Palo Duro Canyon since the Barbary vegetation types during their 18-month study indicated this sheep season was opened in Texas in 1963 (TP&W dept. rec.) species preferred SD 9 and SD 15 andlor factors closely and 1,008 animals have been harvested in New Mexico (Mor- associated with these 2 series in the Guadalupe Mountains rison 1980). Despite this hunter-harvest in excess of 2,000 study area. head, our data indicate the overall population of Barbary sheep in the southwestern U.S. had increased to approximate- Past sightings of Barbary sheep in other areas of the Guada- ly 6,500 free-ranging sheep by 1980. lupe Mountains indicate the species is not limited to these

Table 2. Summary of responses to survey on Barbary sheep conducted through Soil Conservation Service Area Offices in western Texas with population estimates for each region.

Number No. Counties No. Counties No. Known No. Counties Estimated' State Counties with Barbary with Captive Escapes (E) or with Free-Ranging Free-Ranging Region Surveyed Sheep Animals Release (R) Animals Population 1980

Panhandle Rolling Plains Edwards Plateau Trans-Pecos

TOTAL 139 37 14 10 26 +- 3,750

'Based on information compiled from all sources.

-12- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS range sites on the steeper slopes of canyon walls. Barbary sheep utilization in the Canadian River drainage also showed population concentration on precipitous slopes (Schwartz pers. comm.), as was found in the Hondo Valley (Dickinson pers. comm.). Barrett (1980) and Johnston (1980) both substantiated the importance of steep, inaccessible country to the California Barbary sheep population.

Wallace (1959) described dispersal from the Palo Duro Canyon release sites as following the edge of the Caprock, and Dickin- son and Simpson (1980a) showed that precipitous terrain was significant in the southward dispersal of Barbary sheep from the Hondo Valley of New Mexico. Thus, population dispersal and range extension pathways of Barbary sheep appear to follow broken topography as a general rule, although some ex- ceptions have been recorded (Simpson et al. 1978).

DISCUSSION Several authors have discussed the potential threat to desert bighorn represented by Barbary sheep. Barrett (1967) did not envision the 2 species as becoming sympatric 11 years ago, and even when Simpson et al. (1978) published their paper, there was no documented case of sympatry. By the time Seegmiller and Simpson (1979) discussed the problem, Bar- bary sheep were sympatric with desert bighorn in the San An- dre~range. Today, as we review the dispersal and establishment of Barbary sheep in the southwest US. in 1980, this LJ 0 Established Free-Ranging species is sympatric with desert bighorn on 3 traditional Populations bighorn ranges. Confirmed Sightings Introduced species in new environments either require Con- + Release Sites tinued supplementary support to survive at all, or flourish and become extremely successful if the habitat proves favorable (Petrides 1968, Pianka 1974). However, in the latter case, they Figure 2. Distribution of Barbary sheep in New Mexi- usually exhibit an exotic vigor and seldom respond to their co in 1980 compiled from various sources. new environments in exactly the same manner as they did in their native habitats (de Vos and Petrides 1967, Petrides 1968). Arrows indicate major dispersal directions As the Barbary sheep clearly represents a successful introduc- based on frequency of sheep sightings. tion, it can be expected to occupy a diversity of habitats and to be a highly aggressive competitor in its utilization of available range resources (Pianka 1974). Dickinson and Simpson (1980b) showed that Barbary sheep vegetation series. Barbary sheep have dispersed long preferred slopes over top and bottom sites, and the same distances through vegetative types ranging from ponderosa authors (1979) found this species selected the SD 9 and SD 15 pinelwhite pine forest to tarbushlcreosotebush flats. However, vegetation series associated with precipitous and broken ter- the SD 9 and SD 15 vegetative series predominantly are rain in the Guadalupe Mountains. In a survey of desert bighorn associated with bluffs and precipitous terrain (> 80% in the habitat in New Mexico these vegetation types represented 2 Guadalupe Mountains study area). These habitats are ap- highly important features of the Guadalupe desert bighorn parently more suited to colonization by Barbary sheep sub- range (Sandoval pers. comm.), thus competition between the 2 populations and may be preferred as dispersal corridors species seemed inevitable. Seegmiller and Simpson (1979) (Dickinson and Simpson 1979). have pointed out the probability for survival of desert bighorn in a sympatric situation, especially should complete niche Analysis of the SCS survey findings showed that all 31 overlap occur. While they rightly consider that total niche respondents to the question on habitat in which Barbary overlap between the 2 species throughout the bighorn range is sheep were first sighted indicated Rough BreakslCaprock unlikely to occur, the evidence presented above does not areas. Breakdown of the 30 dispersed animal observations preclude total niche overlap in specific localities. recorded in New Mexico in Fig. 2 showed 27 were associated Population estimates for any species which occupies remote with or adjacent to rough terrain. and relatively inaccessible country are, at best, educated guesses. The estimates of total free-ranging Barbary sheep in Topography and slope are of major importance to Barbary each state in 1980 given in Table 1 represent a conservative sheep habitat and apparently take precedence over vegetative figure based on population by population evaluation in types. Dickinson and Simpson (1980a) found Barbary sheep in cooperation with several management agencies. Thus, the ap- the Guadalupe Mountains remained between 4000' and 7000' proximately 400 Barbary sheep originally released to the wild elevation, and that the majority of their activity was concen- had increased to some 6,500 animals by 1980, covering a large trated on slopes rather than on top or bottomlands (Dickinson area of the Southwest (Fig. 3). These figures are of particular and Simpson 1980b). In Palo Duro Canyon, Simpson and Gray significance when compared with recent estimates of desert (in review) also recorded this phenomenon; while there was bighorn sheep numbers in the United States. Wishart (1978) some seasonal variation in location of animals, the greatest and Wilson (1979) estimated total desert bighorn numbers at degree of topographic use in all seasons was of Rough Breaks between 13,000 and 14,500 animals, but Valdez (1981), in a

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -13- detailed mountain range by mountain range survey, only found centers for westward emigration of Barbary sheep into Arizona 11,600-11,700 sheep remained by 1980. Thus, despite intensive (Fig. 3). conservation and management throughout their range over the Research on the Californian population (Barrett 1980, past 50 years, the desert bighorn populations have continued Johnston 1980) has not indicated that this population of Bar- to decline. On the other hand, the unmanaged and heavily bary sheep poses a threat to bighorn sheep in the present cir- hunted Barbary Sheep populations have expanded and cumstances. Not only do resources appear to be limiting dispersed widely through the Southwest (Fig. 3). and in 25 population numbers, but hunter-removal of dispersing animals years have increased to more than half the total desert bighorn appears to be effectively preventing colonization of new range. numbers. However, this situation could change rapidly if protective For the Texas herd, growth and dispersal from the.Palo Duro legislation were enacted in favor of Barbary sheep, or dispers- Canyon population has been discussed elsewhere (Simpson et ing animals were permitted to cross east into historic bighorn al. 1978, Gray 1980, Gray and Simpson in review). The alarming range (Fig. 3). increase in Barbary sheep in the Trans-Pecos region is of in- The failure of this species to become successfully established terest and concern to desert bighorn biologists. The fact that 3 in Colorado would indicate that range expansion to the north relatively small introductions made in the 1950's and 1960's may be limited by some habitat restraints, perhaps safeguard- have grown into a population of over 1,000 free-ranging ing this state from Barbary sheep invasion. Judging by the animals is alarming in itself. The main lesson to all land enormous westward range expansion exhibited by Barbary management agencies, however, lies in the dispersal of this sheep in the 19701s, however, it is this direction that the population to every mountain range in the region. Not only greatest threat apparently lies (Fig. 3). The arrival of the have Barbary sheep clearly demonstrated their ability to sur- species at the southern end of the Continental Divide and its vive and thrive in desert conditions, in the process they have appearance on the threshold of Arizona is not to be viewed taken over virtually all the traditional desert bighorn habitat in lightly. Whereas Texas and New Mexico had only 117 desert the Texas Trans-Pecos region (Fig. 1). bighorn left in 1980, Arizona had 4,000 of the remaining The Barbary sheep herd in New Mexico again epitomizes the animals (Valdez 1981). exotic vigor of the species, and its wide-range dispersal and A certain degree of complacency has been exhibited by some colonization of a diversity of habitats demonstrates a new agencies whose jurisdiction has not, as yet, been invaded by found plasticity probably missing in its native African environ- the Barbary sheep. Too much uncertainty exists as to the out- ment. The last 10 years have shown this species dispersing come of competition between desert bighorn and Barbary widely in eastern New Mexico, and 1980 distributions indicate sheep, however, to risk further infiltration into traditional it has probably colonized all suitable areas in that half of the bighorn range. This insidious exotic must be stopped at all state (Fig. 2). Movement also has occurred in northern parts of costs before it spreads any further, at least until the outcome the state, resulting in sightings from areas considered un- of interspecific competition is known. The future survival of suited to permanent occupancy by this species. However, this the desert bighorn in the U.S. may be in the balance and it is movement has led to the establishment of populations in the responsibility of every conservationist to see that the out- northwest New Mexico which may act as future dispersal come is in favor of the native desert bighorn sheep.

Figure 3. Barbary sheep distribution in the southwest U.S. and Mexico in 1980 related to historic bighorn nabitat.

-14- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS LITERATURE CITED qrmstrong, W.E. 1979. Survey of exotics in Texas. Texas Parks STRESS: CHANGING Wildl. Dep. Job Compl. Rept. Proj. No. W-109-23, Job 6, 14 PP. ENVIRONMENTS AND 3arrett, R.H. 1966. History and status of introduced ungulates on Rancho Piedra Blanca. M.S. thesis, Univ. Michigan, THE EFFECTS ON Ann Arbor, MI. 141 p. . 1967. Some comparisons between the Barbary DESERT BIGHORN SHEEP sheep and the desert bighorn. DBC Trans., pp. 16-26. . 1980. History of the Hearst Ranch Barbary sheep herd. Proc. Syrn. Ecol. Manage. Barbary Sheep, Texas Tech Univ., Lubbock, pp 46-50. James R. DeForge Bird, W. and L.L. Upham. 1980. Barbary sheep and mule deer Society for the conservation of Bighorn Sheep food habits of Largo Canyon, New Mexico. Proc. Syrn. Ecol. Manage. Barbary Sheep, Texas Tech Univ., Lubbock, Upland, CA pp. 92-96. de Vos, A. and G.A. Petrides. 1967. Biological effects caused Abstract: The deterioration of the bighorn's environment can by terrestrial vertebrates introduced in non-native environ- cause stress, which can lower the animal's resistance to ments. 10th Tech. meeting, IUCN. Pubs. News Ser. No. 9: disease. Some of the recent bighorn die-offs may be stress 113-119. related and possibly triggered by environmental changes. In Decker, E. 1973. Exotics pages 229-256. In Schmidt, J.L. and order to better understand the effects of stress, we should D.L. Gilbert (Eds.). Big Game of North America, Ecology combine studies on behavior, physiology, and medical and Management. Wildl. Manage. Instit. and Stackpole research and relate the data to environmental conditions. Books, Harrisburg, PA, 494 pp. Behavior studies alone only give information on outward reac- and C.D. Simpson. 1979. Dispersal and establish- tions and do not supply a complete picture of the effects of ment of Barbary sheep in the Southern Great Plains. Final stress. Rept. to USDA Forest Service, Rocky Mtn. For. & Range Exp. Stn., RM 1713, Lubbock, TX, 52 pp. Stress can be defined as any stimulus or succession of stimuli and . 1980a. Dispersal and establish- of such magnitude as to tend to disrupt the homeostasis of an ment of Barbary sheep in southwest New Mexico. Proc. organism. Thus the deterioriation of an animal's environment Sym. Ecol. Manage. Barbary Sheep, Texas Tech Univ., can induce stress. Stress is an adaptive phenomenon direct- Lubbock, pp. 33-45. ing the animal's responses toward coping with environmental and . 1980b. Home range, movements, change. An animal meets changes by producing appropriate and topographic selection of Barbary sheep in the responses which reduce stress. But as mild stress helps to ad- Guadalupe Mountains, New Mexico. Proc. Syrn. Ecol. just the individual to his environment, as stress increases, the Manage. Barbary Sheep, Texas Tech Univ., Lubbock, pp animal's ability to cope and survive is lessened. The bighorn 78-86. differ from some ungulates in their attempts to escape from stressful situations. Two points need consideration: (1) Gray, G.G. 1980. Aspects of Barbary sheep (Ammotragus Bighorn usually do not explore for new territory, as deer do, lervia) biology in Palo Duro Canyon, Texas. PhD disserta- and therefore are not considered to be good dispersers. tion, Texas Tech Univ., Lubbock, 175 pp. Whether sheep are poor dispersers due to a loss of pioneering and C.D. Simpson. Population characteristics habits, or whether environmental limitations prevent this ex- of free-ranging Barbary sheep, Ammotragus lervia ploration, is academic. For either reason, the bighorn is usual- in Palo Duro Canyon, Texas. Ms. in review. ly loyal to existing home range. (2) The bighorn live in an open Harmel, D.E. 1980. Statewide census of exotic big game ani- environment and rely on their eyesight and an acute ability to mals. Performance Report, Project No. W-109-R-3, Job No. negotiate rocky precipitous terrain to avoid adverse stimuli. 21, 33 pp. Whereas deer can avoid disturbance by hiding, thus minimiz- Jackson, A. 1964. Texotics. Texas Game Fish 22(4):7-11. ing the trauma, the bighorn must set a flight distance between Johnston, D.S. 1980. Habitat utilization and daily activities himself and the object eliciting the responses. Since the of Barbary sheep. Proc. Sym. Ecol. Manage. Barbary bighorn is not likely to disperse, when confronted with adverse Sheep, Texas Tech Univ., Lubbock, pp. 51-58. stimuli his usual action is to reduce his range. resulting in the direct reduction of resources. This lack of beha:.ioral or evolu- Morrison, B.L. 1980. History and status of Barbary in New tionary options possibly accounts for the bighorn's sensitivity Mexico. Proc. Sym. Ecol. Manage. Barbary Sheep, Texas to environmental disturbances. Tech Univ., Lubbock, pp. 15-16. Ogren, H.A. 1965. Barbary sheep. New Mexico Dept. Garr~e& The body responds to stress by one of three pathways: (1) Fish, Bull. No. 13, Santa Fe, NM, 117 pp. voluntary motor response, (2) the sympathetic nervous system by which the adrenal medulla stimulates release of Petrides, G.A. 1968. Problems in species introductions. acetylcholine and induces the flight or fight reaction, or (3) the IUCN Bull. 2(7):70-71. neuroendocrine system through which the adrenal cortex releases cortisol and other glucocorticoids that cause protein and fat catabolism and blockage of the immune response (Fowler 1978). In order to produce sufficient hormones to regulate body functions under stress conditions, the adrenal cortex enlarges. Continuous adrenal cortex stimulation and excessive production of cortisol can cause a sudden and complete breakdown in the endocrine mechanism. Many of the effects of stress are functional, leaving no

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -15- definitive physical lesions to mark their presence (Fowler and relating this data to environmental conditions. MacArthur 1978). Tissues and organs become weakened by prolonged et a/. (1979) have produced important quantitative data. Work stimulation, lowering resistance by impaired antibody of this type needs to be continued and is far better than responses to diseases such as pneumonia, scabies, and behavioral studies alone to indicate stress. In addition to heart lungworm, and eventually leading to death. The actual causes rate monitoring, the endocrine system needs to be evaluated. of death may be the pneumonia, parasitism, or starvation, but Levels of serum cortisol and immunoglobulins need to be stress has paved the way for the development of the ailments studied. Too often researchers and managers take a "hands and thus in reality has become the primary cause of this loss off" approach to bighorn management. Jendron could not of life. Research has shown a number of other effects due to have found amyloidosis nor Spraker have found Pasteurella stress, including inhibition of reproductive functions and in- pneumonia without fresh necropsy specimens. New Mexico creased behavioral abnormalities. could not have treated their scabies outbreak, nor could Col- orado have found and treated their lungworm-pneumonia pro- The large and sudden die-offs reported in bighorn literature blem (Hibler eta/, 1977) without a "hands on" approach. cause us to question whether stress is involved in many bighorn losses. Did stress lower the resistance of these The bighorn generally has shown a high sensitivity to en- animals to disease? For example, the Waterton Canyon vironmental changes. They maximize their fitness best in a bighorn die-off in Colorado is suspected to be related to stress predictable environment. When predictability is anything less of dam construction, low burdens of lungworm, and confine- than optimal, physiological changes occur, lessening the ment to a small area by heavy vegetation and restricted water animal's ability to survive. As long as the environment con- availability (Brian W. Simmons, personal communication). tinues to be degraded, we can expect the bighorn to be under New Mexico's large die-off from scabies (Sandoval 1980): was stress, and we might well see the continuation of epidemics this mite always present in the range? If so, what weakened and die-offs. The decline of the bighorn in many areas of North the animals' resistance, allowing the parasite to overtake this America demands that we use every possible method to population? Was stress a factor? Bighorn have disappeared research and evaluate bighorn problems if we are to in- from 16 mountain ranges in California in the last third century telligently manage this species. (Weaver 1979, DeForge et a/. 1981). Why? Does stress induced by California's swelling human population play a part in these LITERATURE CITED losses? DeForge, J.R., C.W. Jenner, A.J. Plechner, and G.W. Sudmeier. The die-off of the captive herd in the Lava Beds National Monu- 1979. Decline of bighorn sheep (Ovis canadensis), the ment, California, due to pneumonia (Dave Jessup, personal genetic implications. Desert Bighorn Counc. Trans. communication): what happened? Spraker (1977) studied three 63-66. all-age die-offs of captive bighorn sheep in Colorado and DeForge, J.R., J.E. Scott, G.W. Sudmeier, R.L. Graham, and believed that these die-offs were related to the stress of cap- S.V. Segreto. 1981. The loss of two populations of desert tivity. These sheep had enlarged adrenal cortexes, which bighorn sheep in California. Desert Bighorn Counc. Trans. Spraker concluded resulted in the animals losing their 36-38. resistance and being overcome by Pasteurella pneumonia. Fowler, M.E. Restraint and handling of wild and domestic Hornaday (1908) reported 73 years ago that bighorn in captivity animals. Iowa State Univ. Press, Ames. pp. 53-62. die of pneumonia. Today pneumonia is still the "scourge" of Hadlow, W.J. and W.L. Jellison. 1962. Amyloidosis in Rocky bighorn, but the reason why is just as confusing as in Horna- Mountain bighorn sheep. J. Am. Vet. Med. Assoc. 141(2): day's time. It appears that we have progressed little. 243-247. Annette Jendron, a pathologist for the Los Angeles County, Hibler, C.P., T.R. Spraker, and R.L. Schmidt. 1977. Treatment necropsied a bighorn ram in 1979 from the Santa Rosa Moun- of bighorn sheep for lungworm. Desert Bighorn Counc. tains, California, and found amyloidosis (personal com- Trans. :12-14. munication). Little is known about this disease in free-living wild animals, but it is characterized by extracellular accumula- Hornaday, W.T. 1908. Camp-fires on desert and lava. Charles Scribner's Sons, New York. 366 pp. tion of amyloid (a protein) in various organs and tissues of the body and is thought to be a deposit of an antigen-antibody MacArthur, R.A., R.H. Johnston, and V. Geist. 1979. Factors complex formed by some deranged immune response within influencing heart rate in free-ranging bighorn sheep: a the body. It has also been found in Rocky Mountain bighorn physiological approach to the study of wildlife (Hadlow and Jellison 1962). Since stress can cause faulty im- harassment. Can. J. Zool. 57(10):2010-2021. mune response (DeForge et a/. 1W9), is this one more expres- Sandoval, A.V. 1980. Management of a Psoroptic scabies epi- sion of stress? zootic in bighorn sheep (Ovis canadensis mexicana) in New Mexico. Desert Bighorn Counc. Trans. :21-28. MacArthur et a/. (1979) evaluated stress on park bighorn by monitoring heart rate, which we assume correlates with Spraker, T.R. 1977. Fibrinous pneumonia of bighorn sheep. energy expenditure. They were able to demonstrate that heart Desert Bighorn Counc. Trans.:17-18. rate was higher during certain stressful situations, including a Weaver, R.A. 1979. Status of bighorn sheep in California. 20 percent rise in mean heart rate during continuous exposure Calif. Dept. of Fish and Game, Sacramento, CA. 7pp. to nearby humans. Possibly even more significant, an increase in heart rate sometimes occurred in the absence of any outward reaction to stressors. Behavior studies of human impact only detect outward reactions and may not be suggestive of an animal's stress level or acceptance of human interactions. It should also be noted that this study was done on park bighorn, where bighorn encounters with humans are usually positive. One would expect even greater stress, heart rate, and energy expenditure on less tame animals. Stress is a complex phenomenon, which today can best be evaluated by combined studies working toward an ecological evaluation tying in behavior, physiology, and medical research

-16- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS northeast-southwest direction approximately 147 km (91 mi) west of Phoenix (Fig. 1). The Harquala Mountains cover ap- 3ROUP ORGANIZATION proximately 311 km2(120 mi2) and the Little Harquahala Moun- 4ND ACTIVITY PATTERNS tains encompass 179 km2 (69 mi2). Climate 3F DESERT BIGHORN Seasons were delineated using temperature and precipitation data from the Aguila station, elevation 695 m (2,280 ft) (U.S. SHEEP Weather Bureau), from 1975 to 1979. Average annual precipitation was 21.80 cm (8.58 in), with April, May and June (early summer) having the lowest average seasonal precipitation (0.49 cm (0.19 in)). January, February, and March MaryEllen Chilelli and Paul R. Krausman (winter) had the highest seasonal precipitation average (3.02 School of Renewable Natural Resources cm (1.19 in)), and July, August, and September (late summer) Jniversity of Arizona, Tucson 85721 and October, November, and December (fall) had respective precipitation averages of 2.02 cm (0.80 in) and 1.54 cm (0.61 in). Abstract. Seasonal group organization and activity patterns Winter had an average seasonal temperature of 10.3 C (50.5 F), 3f desert bighorn sheep (Ovis canadensis mexicana) were early summer was 20.8 C (69.4 F), late summer was 28.1 C (82.6 studied in the Harquahala and Little Harquahala Mountains in F), and fall was 14.1 C (57.4 F). During the study, the highest western Arizona during 1979 and 1980. Average group size of temperature of 44.4 C (111.9 F) occurred on 30 June 1980 and bighorn in the Harquahala Mountains, ranging from 2.5 to 4.5, the lowest of -6.7 C (19.9 F) on 17 November 1979. was largest in the early summer. In the Little Harquahala MATERIALS AND METHODS Mountains, group size averages varied from 6.1 to 16.2. Mixed groups were larger than ewe groups, with no significant size Fifteen bighorn sheep were captured between 8 November difference (P (0.05) between ram and ewe groups. Group type 1979 and 5 November 1980: 2 yearling rams, 4 adult rams, 2 is related-to season in the Harquahala population. Ewe groups yearling ewes, and 7 adult ewes. Desert bighorn sheep were were more numerous during the first half of the year. In late located with a helicopter, immobilized with M-99, collared with summer and fall, adult ram composition within mixed groups color-coded radio telemetry collars, and released. increased. Adult ewes were the primary leaders in mixed and Sex and age classifications were made according to the ewe groups. Group integrity was not apparent for bighorn methods of Hansen (1965) and Geist (1971). Adult rams were sheep in the Harquahala Mountains. Daily activity patterns placed into horn size classes from I to IV. Group types follow changed seasonally, primarily in bedding and feeding peaks. Geist (1971): ewe groups consist of adult ewes, yearlings, and Breeding behavior peaked from August to October. Newborn lambs; mixed groups are comprised of adult rams, adult ewes, lambs were observed from December 1979 to April 1980. yearlings, and lambs; and ram groups have only adult rams. INTRODUCTION Radio collared sheep were systematically located by aerial This study was conducted in the Harquahala, and Little Har- and ground telemetry. Small fixed-wing aircraft were used for quahala Mountains, Arizona (Fig. 1). In 1978, the Harquahala aerial locations. Ground observations were made with 9 x 36 population was estimated to be between 39 and 45 sheep binoculars and a 20x spotting scope. (Arizona Game and Fish Department 1978). A minimum of 20 Ground surveys were concentrated in the Harquahala Moun- sheep are in the Little Harquahala Mountains. tains. For ground observations, sex and age composition of Research on seasonal activity patterns and alterations in com- each group was recorded to determine if there were significant position of desert bighorn bands is limited. Simmons (1969) differences in the average group size between seasons and studied social organization and behavior of 0.c. mexicana on the Cabeza Prieta Game Range, Arizona. Welch (1969) and Augsburger (1970) delineated activity patterns for 0. c. mexicana in New Mexico. Golden and Ohmart (1976) and Olech (1979) studied summer activity patterns of 0. c. mexicana and 0. c. cremnobates, respectively. Our study was undertaken to describe seasonal differences in group size and composition and to delineate seasonal activity patterns of desert bighorn sheep in western Arizona. The study was conducted from May 1979 to December 1980. We thank J.J. Hervert of the University of Arizona for providing ,373-4 many of the reported observations. Acknowledgment is given c, // - - - * / to other University of Arizona personnel involved in this project \-' -..\. /' including L.L. Ordway, R.A. Ockenfels, and C.J. Chilelli for _Tonopah assisting with data collection, Dr. R.O. Kuehl for assisting with Location of Study ~ras statistical analysis, and B.D. Leopold for preparing the com- I"" puter program for activity pattern data. Drs. N.S. Smith and

W.W. Shaw provided critical review of the manuscript. R. 0 I0 20 I Bauman and ,B. Campbell of the Bureau of Reclamation (BR) Kilometers assisted with the initial phase of the project. J. deVos, R. Rem- ington, and T. Peoples of the Arizona Game and Fish Depart- ment captured and assisted in collaring sheep. Financial support was provided by BR and the U.S. Fish and Wildlife Service.

STUDY AREA Fig. I. Location of the tlarquahala Mountains, Little Location and Physiography Harquahala Mountains, and surrounding The Harquahala and Little Harquahala Mountains lie in a ranges in western Arizona.

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -17- mountain ranges and if composition within ewe and mixed to another, excluding feeding behavior. Standing activity is groups differed between seasons and mountain ranges recorded with notation whether or not the animal is alert, head (Bhapkar 1968). Changes in group composition and percen- up, and looking around. Sexual activity includes lipcurl, snif- tages of mixed and ewe groups were used in delineating the fing the rear or urine of another animal, courting, attempted breeding season, when the number of rams among ewes in- andlor successful mounting. Resource competition is the act creases. Group composition also was used to determine group of pushing another bighorn away from shade, food, water, or integrity, limiting this analdsis among the collared sheep other resources. Aggressive activity includes kicks, clashes, or where individual animals could be identified. Group integrity butts towards other sheep. Attempted and successful suckl- was analyzed using a 2-way frequency table (Dixon and Brown ing is recorded as nursing. Contact greeting includes rubbing, 1979) in a quasi-independence test (Bishop et al. 1975). In- horning, and nuzzling of other sheep, and the various horn dividual bighorn sheep whose movement appear to influence displays described by Geist (1971) are recorded as dominance other sheep to follow them were defined as leaders. Whenever display. observed, leaders of each group were recorded to determine Activity patterns were recorded at 5-minute intervals. Detailed which animals are leaders in different group types (Goodman activity was noted for the period between the activity data 1965). Data were tested using Chi-square analysis at the 0.05 points. An activity hour is defined as 12 activity data points on level of significance, unless otherwise specified. one desert bighorn. Frequency of occurrence of activity pat- Observations of individual animals tend not to be independent terns for each hour during the day were derived for each due to the gregarious nature of desert bighorn sheep. season. However, the basic assumption underlining the activity pat- RESULTS AND DISCUSSION tern research method was that the animals observed are representative of the population. Activity pattern data were Group Size collected to determine the daily patterns and how these A total of 197 desert bighorn group observations (759 sheep) change between seasons. Eleven main activity patterns were was recorded. Group sizes ranged from 1 to 22 (Fig. 2). Average delineated, based upon Geist (1971), with the following defini- group size was largest during early summer in the Harquahala tions. Mountains (Table 1); this seasonal group size differs from the fall average (PC0.10). Average group sizes in winter, late sum- Feeding activity includes browsing, chewing, and walking be- mer, and fall did not differ significantly. Simmons (1969) and tween food items. Watering activity is recorded when the Deming (1953, cited by Hansen 1980) frequently found group animal's head is lowered at a water source. Bedding occurs sizes from 1 to 3. Slightly larger groups of 3 to 5 were reported when the animal is lying down with head down or head up and by Russo (1956), Welles and Welles (1961), Golden and Ohmart the animal is alert. Movement is a direct travel from one point (1976), and Leslie and Douglas (1979).

Harquahala Population

Little Harquahala Population

10 15

Group Size

Fig. 2. Frequency of desert bighorn group sizes in the Harquahala and Little Harquahala Mountains from May 1979 to December 1980.

-18- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS Table 1. Seasonal mean group sizes of desert bighorn sheep in the Harquahala (H) and Little Harquahala (LH) Mountains from May 1979 to December 1980.

Mean Group Size Total Sheep Observed No. Groups

Season H LH H LH H LH

Winter Z.g(O.15) 69 24 Early Summer 4.5(0.49) 16.2(1.15) 207 81 46 5 Late Summer 2.5(0.05) 11.0(6.22) 161 33 65 3 Fall 3.1(0.15) 6.1(1.34) 89 86 29 14

Variances are in parentheses.

Seasonal average group sizes in the Little Harquahala popula- Range, Arizona (Simmon 1969) and in British Columbia (Blood tion varied from 6.1 to 16.2 and were larger than in the Har- 1963) the mean group size of mixed groups were larger than quahala population (Table 1). Larger bighorn group sizes in the ewe groups, which were larger than ram groups. Little Harquahalas may be partly attributed to the smaller area Whereas the overall group size average in the Harquahalas of this range reducing the size of suitable habitat and, thus, was largest in early summer, ewe and mixed groups were bighorn sheep dispersion. significantly larger during winter and early summer than dur- In both populations, the largest average group size occurred in ing the other 2 seasons (Table 2). Ewes were congregating in early summer. McQuivey (1978) noted the highest average the western end of the Harquahala Mountains in winter during group size of 4.7 in spring, and Welch (1969) similarly found the lambing. The large mixed and ewe group sizes in early summer largest groups in late winter and early spring. The larger may have been a response to food abundance; ewes with new groups found here and by other researchers may be attributed lambs remained in the western part of the range during this to the greater availability of food during this season; fresh season. There was no seasonal change among Harquahala vegetational growth was present during April and the first part ram groups. of May, and fruits and seeds were available in June. Welles As with overall group averages, group type averages were and Welles (1961.) related the gregariousness of sheep to the usually larger in the Little Harquahala population (Table 2). relative abundance of their food supply. Once exception occurs in fall when the Harquahala and Little When mixed groups were observed in the Harquahalas, they Harquahala ewe group averages were 1.8 and 1.0, respectively. were larger than ewe groups; this also was the case during fall in the Little Harquahala population (Table 2). No mixed groups Seasonal groups and mixed groups were largest in early sum- were seen during winter. In late summer and fall, mixed groups mer, and ewe groups were greatest in winter. This finding con- in the Harquahala Mountains also were larger than ram forms with reports by Welch (1969) and McQuivey (1978). Har- groups. Only solitary rams were observed in the Harquahalas quahala mean group sizes fall in the range of sizes noted in from January to June. There was no significant difference be- other studies (Deming 1953, cited by Hansen 1980, Russo 1956, tween ewe and ram group size averages during late summer Welles and Welles 1961, Simmons 1969, Golden and Ohmart and fall in the Harquahala population. No ram groups were 1976, and Leslie and Douglas 1979). Group sizes in the Little observed in the Little Harquahalas. In the Cabeza Prieta Game Harquahala population were noticeably larger. The trend in

Table 2. Seasonal group type sizes of desert bighorn sheep in the Harquahala (H) and Little Harquahala (LH) Mountains from May 1979 to December 1980. Meansize - - Season Group type H LH H LH H LH

Winter Mixed Ewe Ram

Early Summer Mixed Ewe Ram Late Summer Mixed Ewe Ram Fall Mixed Ewe Ram

Variances are in parentheses.

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -19- &xed Group

Ewe Group

C] Ram Group

Winter Early Summer Lale Summer Fall SEASONS

Fig. 3. Seasonal desert bighorn group composition in the Harquahala (H) and Little Harquahala (LH) Mountains from May 1979 to December 1980.

group type sizes, mixed groups larger than ewe groups which year (winter and early summer) than the latter half (Fig. 3). were larger than ram groups, was noted here and by other Seasonal comparisons of the percentage of mixed to ewe researchers (Blood 1963 and Simmons 1969). groups show significantly more ewe groups present in the Har- Group sizes in the Harquahala Mountains were smaller than quahalas during winter and early summer; however, in late those reported in more northern populations, with averages summer and fall the percentages of these 2 group types ranging from 5.3 to 16 (Smith 1954, Blood 1963, and Brown observed did not differ. In the Little Harquahalas, the percen- 1974). Berger (1978) suggested that the smaller groups in tage of ewe groups decreased from April to December, with no desert regions may be a response to patchy food distribution. significant difference in the percentages of mixed and ewe However, the Little Harquahala population had group groups during fall (Fig. 3). Although no mixed groups were averages as large as those reported in northern populations. observed in winter during this study, several mixed groups The larger groups in the Little Harquahala population may were observed in the Little Harquahalas during January 1981. partly be a response to the smaller area in this range; however, In the Harquahala population, adult ram composition of mixed further studies in these 2 areas may suggest explanations for groups was significantly greater in late summer and fall than these larger groups. in early summer. Adult ewe and yearling composition of mixed Group Composition groups did not change seasonally. Mixed group lamb compos- Desert bighorn sheep group type is related to season in the ition decreased from early to late summer, with no change in Harquahala Mountains. The seasonal percentages of mixed lamb composition during the latter half of the year (Table 3). In groups changed little in the Harquahalas; whereas, the propor- ewe groups, ewe and yearling seasonal composition did not tion of ewe groups observed was larger in the first half of the change statistically; lambs decreased from winter to early

Table 3. Seasonal composition of desert bighorn sheep mixed and ewe groups in the Harquahala (H) and Little Harquahala (LH) Mountains from May 1979 to December 1980.

Total Percent Percent Percent Percent Percent number arcups adultrams adult ewes vearlinw lambs urdassified

Season Group type H LH H LH H LH H LH H LH H LH

Winter Mixed 0 0 Ewe 20 0 56 16 28 Early Mixed 15 0 25 51 4 13 7 Summer E,, 28 3 71 46 22 4 7 50

Late Mixed 29 1 41 11 45 11 9 0 5 22 56 Summer E,, 17 2 56 46 26 0 18 54 Fall Mixed 17 9 40 14 55 38 5 1 0 38 9 Ewe 6 4 82 100 9 0 9 0

-20- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS summer, and then remained stable for the remainder of the number of activity data points per hour are 90 for winter, 425 year (Table 3). This decrease in the percentage of lambs in ewe ior early summer, 248 for late summer, and 356 for fall. All and mixed groups during winter and early summer was ex- daylight hours are represented, with 75% of the observations pected due to newborn lamb mortality. occurring between 0905 and 1655h. Early morning hours were spent in locating sheep. As a result, the period from 0545 to Adult ewes constituted a larger percentage of ewe groups 0905h is not represented as much as other hours. The daily ac- than mixed groups in the Harquahalas during early summer; tivity pattern changed seasonally, primarily in bedding and this difference was not noted in late summer or fall. In the Lit- feeding peaks. During the active periods, when bedding con- tle Harquahalas during fall, ewe groups consisted solely of adult ewes, but the number of ewes was greater in mixed stituted less than 50% of the activity, feeding was the primary behavior from 0545 to 0755h and 1600 to 2005h in all seasons. groups (Table 3). Differences between the seasons are discussed below. Thus, not only was there a greater proportion of ewe groups in winter and early summer, a larger percentage of ewes were Winter. There were 2 periods in which bedding comprised associated with this group type during these seasons. In late over 50% of the activity, 0900 to 1055h and 1200 to 1355h (Fig. summer and fall, adult ram composition within mixed groups 4). During the active periods, feeding was the primary activity increased. These data indicate the greater association of rams from 0545 to 0755h and 1400 to 2005h. Standing was the main with ewes during late summer and fall. Several researchers nonbedding activity from 0800 to 0855h; and from 1100 to also have indicated that adult rams mingle with ewes in late 1155h, standing and feeding had nearly equal occurrences. summer and fall during the rut and separate from ewes for the Movement became more apparent after 1800h. Nursing was remainder of the year (Welles and Welles 1961, Simmons 1969, observed periodically during the day. McQuivey 1978, and Leslie and Douglas 1979). Early Summer. For early summer (Fig. 5), bedding occurred at least 50% of the time from 0800 to 1155h and 1400 to 1555h. Due to small sample sizes in the Little Harquahalas, com- During the remainder of the day, there were 3 main feeding parisons of sex and age composition of group types between periods: 0545 to 0755h, 1200 to 1355h, and 1600 to 2005h. The the Harquahalas and Little Harquahalas generally could not majority of feeding occurred prior to 0800 and after 1600h. be made. There was no significant difference in lamb composi- Behaviors seen less than 1 % of the time include aggression, tion in fall ewe groups between the 2 ranges. However, the contact greeting, and dominance displays. number of lambs observed during the year was larger in the Lit- tle Harquahalas than in the Harquahala Mountains. This Late Summer. In late summer (Fig. 6), bedding was the main aspect of bighorn sheep ecology should be investigated fur- activity from 0900 to 0955h and 1200 to 1455h. During active ther. In fall, adult rams and ewes constituted a greater percen- periods, feeding was the primary activity from 0545 to 0755h tage of mixed groups in the Harquahalas than the Little Har- and 1500 to 2005h, standing was the main activity from 0800 to quahalas, which may be accounted for by the larger percen- 0855h and 1000 to 1055h, and from 1100 to 1155h feeding and tage of lambs in the Little Harquahalas. Ewe group composi- standing had nearly the same occurrence. Thus, from 0800 to tion during this season did not differ between the 2 ranges. 1455h, when sheep were not primarily bedding, their main activity was standing; both behaviors aid in conserving energy Leadership and Group Integrity during the heat of the warmest season. Olech (1979) observed Generally, adult ewes were the primary leaders in mixed and activity patterns of peninsular bighorn sheep (0.c. crem- ewe groups. In mixed groups, adult ewes were leaders in nobates) during the summer around waterholes. Her results in- 81.8% of the observations (CI =61.3-92.2%). Although Geist dicate greater than 50% activity in mixed groups from 1100 to (1971) never observed large rams following ewes, several 1330h. This activity includes interacting, moving, standing, researchers (Welles and Welles 1961, Simmons 1969, and drinking, and feeding. The greater midday activity of mixed Woolf et al. 1970) noted that ewes generally lead rams. Since groups observed by Olech than found in the sheep during late adult rams primarily associate with ewes only during the summer in this study may be a result of the peninsular sheep breeding season, ewe leadership within mixed groups may be bging close to water. due to the sexual attraction of rams to ewes. Adult ewes also were the primary leaders in ewe groups, comprising 92.8% of The majority of feeding occurred prior to 0800 and after 1500h the observations (CI = 73.1-98.4%). Ram groups were small in this study. During hot weather, Welles and Welles (1961) and leadership changed among the adult rams. In the majority observed sheep browsing in early morning and late afternoon of all leadership cases, adult animals were the leaders; and evening. Sexual and aggressive behaviors occurred most however, leadership is not considered permanent but alter- frequently during late summer. Contact greeting and nates among adult sheep. dominance displays constituted less than 1% of the activity. In the Harquahalas, association was analyzed using those Fall. During the fall (Fig. 7), there was only one peak in which animals which were collared for at least 9 months in 1980. bedding constituted over 50% of the activity, 0900 to 1055h. Group integrity was not apparent in these bighorn groups. During the other periods, feeding was the primary activity, ex- Leslie and Douglas (1979) suggested that group integrity may cept from 1500 to 1555h in which feeding and standing had be density dependent, with cohesion enhanced at lower den- identical occurrences. Feeding was observed primarily prior to sities. They found very flexible intraspecific associations in 0900 and after 1400h, increasing to dusk. Second to late sum- the River Mountain herd in Nevada, with 2.84 bighorn mer, sexual behavior was frequent during the fall; resource sheeplkm2 (7.36 bighorn sheeplmi2). Our results do not con- competition had less than 1% occurrence. form'to the density dependence pattern. In the Little Har- In warm and cold seasons, Welch (1969) found similar activity quahala Mountains there were 0.11 bighorn sheeplkm2 (0.29 patterns, with activity peaks from approximately 0900 to llOOh bighdrn sheeplmi2). The Harquahala Mountains had 0.13 to and in early and late afternoon. Augsburger (1970) observed 0.14 sheeplkm2 (0.32 to 0.38 sheeplmi2). The densities in these sheep feeding from before dawn to noon, with midday bedding 2 ranges were less than in the River Mountains, and still no of 1 hour in the cool season and 2 hours in the warm season. group integrity was noticed. Bighorn sheep then fed and bedded periodically during the Activity Patterns afternoon and evening until they bedded after dark. There were 1,275 activity hours recorded on 651 desert bighorn The social interactions observed among bighorn sheep in the sheep from 2 September 1979 to 31 December 1980. Sheep Harquahala and Little Harquahala Mountains are less intense were observed during all seasons from 0545 to 2005h, except than those described by Geist (1971) in northern populations. in fall when observations did not exceed 1900h. The mean Sexual, aggressive, contact greetings, dominance displays,

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -21- 0Bedding 0Moving rmrmj sexual Nursing

a Feeding Standing Aggression Resource Corn~etition

Fig. 4. Daily activity pattern for desert bighorn sheep in western Arizona, winter 1980.

TIME OF DAY zdos

Fig. 5. Daily activity pattern for desert bighorn sheep in western Arizona, early summer 1980.

-22- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS 0Bedding IMoving llDlll Sexual Nursing

Feeding Standing Aggression Resource Competition

05-45 2d05 TIME OF DAY

Fig. 6. Daily activity pattern for desert bighorn sheep in western Arizona, late summer 1979 and 1980.

TIME OF DAY

Fig. 7. Daily activity pattern for desert bighorn sheep in western Arizona, fall 1979 and 1980.

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -23- and resource competition behaviors generally constituted 1 % Goodman, L.A. 1965. Simultaneous confidence intervals for or less of the activity within each hour. Berger (1978) found multinomial proportions. Technometrics 7:247-254. desert bighorn sheep had a lower behavioral diversity than nor- Hansen, C.G. 1965. Growth and development of desert bighorn thern populations; he attributed this simpler repertoire to sheep. J. Wildl. Manage. 29(2):387-391. smaller group sizes, less social facilitation, and reduced play among lambs in desert bighorn populations. . 1980. Population dynamics. In G. Monson and L. Sumner, eds. The desert bighorn; its life history, Reproduction. Sexual activity was observed whenever rams ecology, and management. Univ. Arizona Press, were in the company of ewes from April to December. Tucson, pp. 217-235. However, breeding behavior became more apparent in June, Leslie, D.M., and C.L. Douglas. 1979. Desert bighorn sheep of increased in July, peaked from August to October, and the River Mountains, Nevada. Wildl. Mono. No. 66, 56 pp. decreased through December. In July 1980, a period of pre-rut was noted, when adult rams were seen in dominance displays Lowe, C.H. ed. 1964. The vertebrates of Arizona. Univ. Arizona and fights. Russo (1956) found the breeding season for Arizona Press, Tucson, 270 pp. bighorn sheep ran from July to October. In the Cabeza Prieta McQuivey, R.P. 1978. The desert bighorn sheep of Nevada. Game Range, the breeding season peaked in July through Biological Bull. No. 6. Nevada Dept. Fish and Game, 81 August (Simmons 1969), and in New Mexico the breeding PP. season for 0. c. mexicana went from August to late October Olech, Lillian A. 1979. Summer activity rhythms of peninsular (Augsburger 1970). bighorn sheep in Anza-Borrego Desert State Park, San Newborn lambs were observed during this study from Diego County, California. DBC Trans., pp. 33-36. December 1979 through April 1980. A lamb less than 1 week Russo, J.P. 1956. The desert bighorn sheep in Arizona. Wildl. old was seen on 23 April 1980. At least 3 lambs, 1 to 2 months Bull. No. 1. Arizona Game and Fish Dept., 153 pp. of age, were observed in February. The sighting of newborn Simmons, N.M. 1969. The social organization, behavior, and lambs in the Harquahala Mountains places the lambing environment of the desert bighorn sheep on the Cabeza season one month earlier and later than that described by Prieta Game Range, Arizona. Ph.D. thesis. Univ. Arizona, Russo (1956) for Arizona. Simmons (1969) found the peak lamb- Tucson, 145 pp. ing to be in December and January, and Augsburger (1970) Smith, D.R. 1954. The bighorn in Idaho. State of Idaho Dept. delineated the lambing season from late December to mid- Fish and Game. Wildl. Bull. No. 1, 154 pp. February. Nursing occurred in the study area from December U.S. Weather Bureau. 1975-1979. Climatological data, Arizona. 1979 through June 1980. Some nursing attempts were noted U.S. Govt. Printing Office, Washington, D.C. Vol. 79-83 through September 1980, but none appeared to be successful. (publ. monthly). Welch, R.D. 1969. Behavioral patterns of desert bighorn sheep in south-central New Mexico. DBC Trans., pp. 114-129. LITERATURE CITED Welles, R.E., and Florence B. Welles. 1961. The bighorn of Anonymous. 1974. Final Environmental Statement, Authorized Death Valley. US. National Park Service, Fauna Series Granite Reef Aqueduct, Central Arizona Project, No. 6, 242 pp. Arizona-New Mexico. U.S. Dept. Interior INT FES 74-75. Woolf, A., T. O'Shea, and D.L. Gilbert. 1970. Movements and Arizona Game and Fish Department. 1978. Bighorn sheep behavior of bighorn sheep on summer ranges in Yellow- management information performance reports, 63 pp. in stone National Park. J. Wildl. Manage. 34(2):446-450. Arizona big game investigations 1977-1978. Proj. W-53-R-28. Augsburger, J.G. 1970. Behavior of Mexican bighorn sheep in the San Andres Mountains, New Mexico. M.S. thesis. New Mexico State Univ., Las Cruces, 54 pp. Berger, J. 1978. Social development and reproductive strategies in bighorn sheep. Ph.D. thesis. Univ. Colorado, Boulder, 143 pp. Bhapkar, V.P. 1968. On the analysis of contingency tables with a quantitative response. Biornetrics 24:329-338. Bishop, Y.M.M., S.E. Fienberg, and P.W. Holland. 1975. Dis- crete multi-variate analysis, theory and practice. MIT Press, Cambridge, MA and London, 557 pp. Blood, D.A. 1963. Some aspects of behavior of a bighorn herd. Can. Field-Nat. 77(2):77-94. Brown, G.W. 1974. Distribution and population characteristics of bighorn sheep near Thompson Falls in northwestern Montana. M.S. thesis. Univ. Montana, Missoula, 134 pp. Deming, O.V. 1953. Lambs of the Nelson bighorn sheep in Nevada. Unpubl. in files of Desert National Wildlife Range, Las Vegas, NV, 143 pp. Dixon, W.J., and M.B. Brown. 1979. BMDP-79 Biomedical computer programs P-series. Univ. California Press, Berkeley, Los Angeles, and London, 880 pp. Geist, V. 1971. Mountain sheep; a study in behavior and evolution. Univ. Chicago Press, Chicago and London, 383 pp. Golden, F.H., and R.D. Ohmart. 1976. Summer observations on desert bighorn sheep in the Bill Williams Mountains, Arizona. DBC Trans., pp. 42-45. -24- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS The authors would like to thank the following individuals who TRANSPLANTING generously took time to respond to our inquiries: James W. Bates, Gerald H. Gates, Grant K. Jense, Jack Kilpatric, Robert DESERT BIGHORN P. McQuivey, Andrew V. Sandoval, Richard A. Weaver, Paul M. Webb, and Charles K. Winkler. We also thank B. Johnson, H. SHEEP-A REVIEW McCutchen, and K. Risenhoover for helpful comments on the manuscript. METHODS Desert Bighorn Council Transactions (1957-1979) were review- Mary M. Rowland ed. Articles that reported transplants of desert bighorn sheep John L. Schmidt (0.c. california and 0.c. canadensis transplants were exclud- Dept. of Fishery & Wildlife Biology ed) were reviewed, and pertinent data were abstracted. In addi- Colorado State University tion, individuals were contacted in states containing historic Fort Collins, CO desert bighorn range (Arizona, California, Colorado, Nevada, New Mexico, Texas, and Utah) in order to obtain the most recent information available. Abstract. Thirteen transplants of desert bighorn sheep were reviewed, of which 11 were successful. Five factors were used Each transplant was rated a success, a failure, or status as evaluation criteria, including: release into historic range, unknown. A transplant in which the current population equall- use of an enclosure, number of sheep released, predator con- ed or exceeded the number of animals initially released was trol, and release of potential familylsocial groups. Release of a considered successful If the population was smaller than the minimum of 20 bighorns into historic range was recommend- number released, the project was considered a failure. If insuf- ed. Although release of bighorns that "know" one another ficient knowledge was available to categorize the transplant, seems desirable, further testing of this hypothesis is needed. or if the release was so recent that such a designation would Use of enclosures and predator control may not be warranted be inappropriate, the project was categorized unknown. Only in all cases, and each potential transplant must be reviewed transplants in which desert sheep had actually been released independently before a decision is made regarding the use of into the wild were included, i.e. if sheep were currently being enclosures and predator control. held in an enclosure, regardless of its size, the transplant was excluded from this review. INTRODUCTION Five factors related to transplanting were used as evaluation Populations of desert bighorn sheep (Ovis canadensis crem- criteria, and questions were posed that could be answered nobates, 0.c. mexicana, 0.c. nelsoni, and 0.c. weemsi) declin- with either a positive or negative response. The questions were ed or existed at precariously low levels since the last century as follows: 1)was the release made in historic bighorn range (Buechner 1960, Monson 1980). Reasons for declines included 2) was an enclosure used to hold animals for an extended poaching, disease, habitat destruction, competition from (more than a day) period of time 3) were at least 20 sheep livestock and feral burros (Equus asinus) (Weaver 1959, released at once 4) was an effort made to control predators Romero 1975, Wilson 1978a), and availability of water (Russo and 5) were transplanted sheep in potential social or family 1956, Wilson 1968). Genetic deficiencies caused by inbreeding groups prior to release? within isolated populations also may have produced low RESULTS AND DISCUSSION numbers of bighorns (DeForge et al. 1979). Because bighorn juveniles do not readily disperse from home ranges of adults, Seventeen transplants were documented in 6 states and in reintroduction of bighorns is the quickest and most efficient Mexico (Table 1). Four transplants of unknown status were ex- method to establish populations in historic or otherwise cluded f;om evaluations related to factors affecting transplant suitable ranges now void of bighorns (Geist 1975, Hansen et al. success. Of the remaining 13, only 2 were considered failures 1980). Transplanting bighorns, especially desert races, has (Table 1). thus far had limited succes (Wilson 1975), and little research Historic Range. With the exception of Tiburon Island, all elucidating the reasons has been conducted (Geist 1975). releases were made in historic desert sheep range. The Common problems have been predation (Broadbent 1969, Tiburon Island release was adjacent to historic range; water Cooper 1974, McCutchen 1978) and disease (Hailey et al. 1972, was the only barrier preventing immigration of sheep to the Bunch et al. 1978). Bailey (1980) postulated that adaptations of island (G. Gates, pers. comm.). bighorns to northern latitudes render sheep relatively unsuited to arid environments, possibly explaining the lack of success Transplanting of sheep into historic range is the least con- in many transplants of desert bighorns. Alternate postulates troversial of the 5 factors considered. Bighorn populations on- certainly exist. ly occupy 10% of their former ranges; consequently, millions of acres of historic range are available for reintroduction Potential for increase in sheep numbers is greater in reintroductions than in relict populations whose habits will likely (Yoakum 1973). Desert sheep should be released into historic range, whenever suitable, before consideration of other poten- keep them restricted (Geist 1975). Through trial and error, tial sites for reintroductions. transplanting techniques have improved, although few agencies are adequately funded or prepared to transplant sheep in Enclosures. Enclosures reviewed for this paper varied in size the manner recommended by Geist (1975), i.e. using humans to from temporary holding pens of 4 ha or less (Kilpatric-1975, lead lambs through ranges of suitable habitat. Wilson et al. McCutchen 1977) to extensive propagating pens that exceed- (1973) established guidelines for reintroduction of desert ed 280 ha (J. Mogart, pers. comm.). Enclosures were used in bighorns, addressing the following categories: historic site unsuccessful transplants and in 3 of 11 successful trans- selection, enclosure location and construction, bighorn plants (Table 1). behavior, capture techniques, transportation, and release. Their recommendations were based on personal experiences Use of enclosures has been recommended to retain by the authors. Review of attempts to re-establish desert transplanted bighorns until numbers were sufficient for bighorn sheep may indicate which of the guidelines have prov- release (Wilson et al. 1973). Other reasons for using enclosures en important and which, if any, are of little consequence. included familiarization of transplanted sheep with local DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -25- habitats at release sites; imprinting of sheep to areas judged to habitat similar to that of the original range; potential pro- to be good bighorn habitat, e.g. lambing grounds and rocky blems associated with using enclosures, as previously escape terrain; and allowing bighorns captured in separate discussed, would be eliminated. Because natural extension of areas to establish a social system prior to release, thereby ranges seems to be of secondary importance to bighorn sheep minimizing dispersal of sheep upon release (Wilson et al. (Geist 1971), using enclosures to imprint sheep to an area may 1973). Although enclosures may have faciliatated transplant not be imperative. To determine whether construction of an success in some situations, they were detrimental in other enclosure is justifiable, therefore, each potential transplant cases. Problems encountered with enclosures included: in- must be evaluated independently. creased incidence of disease (Bunch et al. 1978, McCutchen Number of Sheep Released. Wilson et al. (1973) recommend- 1978), predation (Broadbeni 1969, Kilpatric 1976), injuries from ed a minimum release of 12 sheep in an enclosure and 20 in a intra-specific competition because of confinement in small direct release. Of the 13 transplants reviewed, 6 met this area (McCutchen 1975, 1976, 1977), and mortality from en- criterion. Two releases (Tiburon Island and Superstition Moun- tanglement of sheep in netting used to construct the tains) contained 19 sheep. Including those 2, a total of 8 enclosure (A. Sandoval, pers. comm.). Also, large enclosures transplants met the proposed criterion, and only 1 of these were expensive to construct and maintain. Direct releases of (Black Gap) was unsuccessful. bighorns eliminate mortality associated with enclosures. Because some mortality of bighorns can be expected in all Sheep released directly into the wild are not stressed by the transplants, release of adequate numbers of sheep is im- presence of an enclosure, from which they may attempt to perative for establishment of a viable herd. Transplanted escape (McCutchen 1977). sheep may be susceptible to predation if introduced into areas Data from this review suggested that enclosures were un- of high predator densities (McCutchen 1979) or until they necessary and perhaps a liability. Only 3 of 5 releases using become familiar with local escape terrain (Wilson et al. 1973). enclosures were successful, which contrasts 100% success Disease may be prevalent among bighorns released in for direct releases (Table 1). However, in successful releases enclosures (Hailey et al. 1972, McCutchen 1978), and in- not using enclosures, all were intrastate transplants. In those dividuals may wander from the release area before transplants, release sites may have been relatively more establishing home ranges (H. McCutchen, pers. comm.). Thus, similar in vegetation and topography to capture sites, thereby the number of sheep released must be sufficient to compen- deemphasizing need of an enclosure. sate for initial losses. Additionally, chances of successful The value in using enclosures is thus confounded with other breeding during the rut may be enhanced by releasing relative- factors, and thus a simple answer to their necessity is not ly large numbers of sheep. possible. Direct release of sheep may be preferable if numbers Whereas older bighorns will explore a new territory, young of sheep released are large enough, and sheep are released in- sheep will tend to follow older animals (Geist 1971).

Table 1. Status of and factors related to success in transplants of desert bighorn sheep.

Country Release Site Status 1 2 3 4 5 ~uthorityb

AZ Aravaipa Success P. Webb; Moore 1960, Webb 1979 Superstition Mts. Success P. Webb GO Colorado Natl. Mon. ? R. Ravey, J. Schmidt; Ravey & Schmidt 1980 MX Tiburon Island Success G. Gates; Montoya and Gates 1975 NV Dutch Creek ? McQuivey; Broadbent ,1969, Tsukamoto 1979 Stonewall Mt. Success McQuivey; McQuivey 1978b, Tsukamoto 1979 Virgin Mts. Success R. McQuivey NM Big Hatchet Mts. Success G. Gates, A. Sandoval; Sandoval 1979 San Andres Mts. Success G. Gates, A. Sandoval TX Black Gap Failure J. Kilpatric; Moore 1958, Kilpatric 1979 Sierra Diablo Success J. Kilpatric; Kilpatric 1975, 1979 UT Parunuweap Canyon Failure H. McCutchen; McCutchen 1977, 1979 Zion Canyon ? H. McCutchen; McCutchen 1975, 1979 Moody Canyon Success J. Bates, G. Jense; Winegardner et 'al. 1977, Jense et al. 1979 San ~afaelSwell Success J. Bates, G. Jense; Jense et al. 1979 Westwater Canyon ? J. Bates, G. Jense; Jense et al. 1979 Kaiparowitts Success J. Bates, G. Jense Totals: Successes 11 Failures 2 aFactors related to transplanting are as follows: I-release on historic range? 2-enclosure used? 3-minimum release of 20 sheep? 4-predator control? 5-release of potential familylsocial groups? b~irstauthority refers to status of reintroduction; all are personal communications, 1981. Literature sources are first and last references reviewed, if more than 1 was available. clncludes 2 releases, of which 1 contained potential familylsocial groups.

-26- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS Transplanting adequate numbers of sheep-both teachers CONCLUSIONS AND RECOMMENDATIONS and learners-will improve chances of successful establish- Because only 13 transplants were included in this review, con- ment of home ranges encompassing suitable habitat. clusions concerning the relative importance of the 5 criteria examined are only tentative. Our review supports recomrnen- Predator Control. Attempts were made to control predators dations (Wilson et al. 1973) that desert sheep be introduced in- in 5 transplants, and 4 of these reintroductions were suc- to historic range and that a minimum of 20 sheep be released cessful (Table 1). Among the 8 transplants where predators into the wild. Transplanting sheep that "know" one another were not controlled, only 1 was unsuccessful. Predator control seems desirable based on current knowledge of bighorn has been recommended prior to and during the first year of in- behavior and theoretical considerations, but the relative irn- troduction (Wilson et al. 1973). portance of this criterion requires further testing. Use of enclosures and predator control should be situation-specific. Predation of transplanted sheep was most often associated Each potential transplant must be evaluated for predator den- with enclosures. Intensive control efforts in Texas, including 2 sities, potential disease problems, numbers of sheep to be years prior to release, were ineffective in preventing losses released, and suitability of habitat before a decision is made from mountain lion (Felis concolor) in the Black Gap enclosure to use predator control or enclosures. Predator control is not (Moore 1958), and predation contributed significantly to the detrimental to transplant success, but enclosures may lead to ultimate failure of that transplant (Kilpatric 1975, 1976, 1979; increased mortality, for reasons discussed previously. Winkler 1977). Although predator control was undertaken Differences among transplants and interrelationships among around the Dutch Creek enclosure 7 months prior to release, at the various criteria were masked because each question re- least 3 sheep were killed by mountain lions within the first year quired a yes or no answer. For example, enclosure size varied (Broadbent 1969); all sheep were subsequently released from greatly, as did the time sheep spent within enclosures. Intensi- the enclosure (Cooper 1974). A predator control program in ty and duration of predator control were variable, and New Mexico failed to prevent predation by coyotes (Canis unreported efforts by ranchers, sport hunters, and trappers latrans) on bighorns (Snyder 1977). In contrast, Arizona person- may have also controlled predators in some instances. In nel used winter application of 1080, with no reports of bighorn releases of 20 or more sheep, numbers ranged from 20 to 42. deaths attributable to predation (Moore 1960, Weaver 1973, This variation may have been significant in explaining out- Hernbrode 1975). comes of individual reintroductions. Predator control was warranted in some instances. McCut- Deeming a transplant successful when the reintroduced chen (1978) believed that more stringent control could have population was stable or increasing was a subjective decision. prevented at least 4 losses in the Parunuweap Canyon Only 2 failures were reported, compared with 11 successes, transplant. He noted, however, that released bighorns adapted rendering explanation of transplant failures difficult. Other to the presence of lions and believed that release of adequate transplants of desert sheep have failed, but were not describ- numbers of sheep would offset losses (H. McCutchen, pers. ed in the Desert Bighorn Council Transactions or discussed by comm.). Removing predators from the immediate vicinity of personnel contacted. the release site may attract transient predators from outlying areas, necessitating continual control (Russell 1973). Predicting transplant success based on any 1 criterion is in- feasible. If all recommendations (Wilson et al. 1973) are met in Because predator control was ineffective in many transplants, transplanting, the probability of success is certainly enhanc- may be costly, and does not alway seem mandatory for ed. However, anomalies do exist, such as the Black Gap transplant success, we do not recommend its use in all transplant, which failed despite ,meeting all 5 criteria used. bighorn transplants. Numbers of sheep transplanted, quality Disease was a major problem in that transplant (Hailey 1969, of habitat, predator densities, and use of enclosures must all Hailey et al. 1972, Winkler 1977). Several other transplants be considered before a decision is made regarding predator were deemed successful although the only criterion met was control. If sheep numbers are low andlor predator densities release on historic range (e.g. San Rafael Swell, Moody Can- high, we recommend predator control until the herd seems yon). A combination of conditions is required for a successful capable of withstanding some mortality from predators. transplant, but this combination will differ with each rein- Release of Potential FamilylSocial Groups. In this review, troduction. It is doubtful that sheep, money, or manpower will bighorns captured in groups (e.g. within corral traps or under be readily available for controlled experiments, in which drop-nets) were assumed to be in potential familylsocial duplicate releases are made with only 1 variable differing, e.g. groups. It is possible that bighorns captured individually were use of an enclosure. Such longterm research and funding are also from previously established groups, especially if captured needed, however, to better understand undocumented failures in a relatively small area. Eight releases contained sheep cap- in desert sheep reintroductions, and results will be applicable tured in groups or held in an enclosure for sufficient time to to conservation of other ungulate species. establish social relationships (Table 1). Two of these were We recommend close monitoring of transplanted sheep, failures. All transplants of bighorns captured individually were preferably with radio-telemetry. Releases of unmarked sheep successful. into remote areas provide little information about the Wilson et al. (1973) recommended transplanting bighorns that transplant's outcome; money, time, and most importantly, have previously interacted socially to reduce agonistic desert bighorn, may be squandered in the process. behavior subsequent to release. They assumed that sheep that Because many transplants of desert bighorns have resulted in "knew" each other were less likely to scatter in smalCgroups additional, isolated populations, more emphasis should be upon release. However, that hypothesis has not been tested placed on using local transplants, where possible. These experimentally, and bighorns released in the Parunuweap Can- transplants will expand ranges of sedentary populations, as yon transplant scattered, despite having been in an enclosure recommended by Bailey (1980). Interchange of individuals be- prior to release. (McCutchen 1978). Disintegration of the herd tween the 2 herds would increase, transmitting knowledge of was attributed to releasing the sheep concomitantly with the good habitats to both groups. Whether desert bighorns are tru- onset of lambing. Although lack of mingling among sheep has ly Pleistocene relicts (Deming 1962, Bailey 1980) in arid refugia been observed in transplants of sheep captured in different or are indeed well-adapted to their environment, their future is areas (Wilson et al. 1973), further research is needed to uncertain. Reintroductions may be the only recourse in main- elucidate the importance of transplanting sheep that "know" taining these unique denizens of the desert and in expanding one another. their present ranges. DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -27- Moore, T.D. 1958. Transplanting and observations of trans- LITERATURE CITED planted bighorn sheep. DBC Trans., pp. 43-46. . 1960. Progress in trapping and transplanting Bailey, J.A. 1980. Desert bighorn, forage competition, and desert bighorn. DBC Trans., pp. 58-59. zoogeography. Wildl. Soc. Bull. 8:208-216. Ravey, R., and J.L. Schmidt. 1980. Evaluation of the reintro- Broadbent, R.V. 1969. Nevada's 1968 transplant disappoint- duction of desert bighorn sheep into Colorado National ment. DBC Trans., pp. 43-47. Monument. Unpubl. semi-annual rept., Colo. State Univ., Buechner, H.K. 1960. The bighorn sheep in the United States, Fort Collins, 19 pp. its past, present, and future. Wildl. Monogr. 4, 174 pp. Romero, M.A. 1975. Comments on burro information analysis. Bunch, T.D., S.R. Paul, and H. McCutchen. 1978. Chronic DBC Trans., pp. 58-60. sinusitis in desert bighorn (Ovis canadensis nelsoni). Russell, K.R. 1978. Mountain lion. In J.L. Schmidt and DBC Trans., pp. 16-20. D.L. Gilbert, eds. Big game of North America - ecology and Cooper, J.R. 1974. Nevada's desert bighorn sheep - 1973 status management. Stackpole Books, Harrisburg, Pa., p 207-225 report. DBC Trans., pp. 31-37. Russo, J.P. 1956. The desert bighorn sheep in Arizona. DeForge, J.R., C.W. Jenner, A.J. Plechner, and G. W. Sudmeier. Arizona Game & Fish Dept. Wildl. Bull. 1, 153 pp. 1979. Decline of bighorn sheep (Ovis canadensis), the Sandoval, A.V. 1979. Bighorn sheep status report from New genetic implications. DBC Trans., pp. 63-66. Mexico. DBC Trans, pp. 82-87. Deming, O.V. 1962. Is the desert bighorn a relict species? Snyder, W.A. 1977. New Mexico's bighorn sheep reintroduc- DBC Trans., pp. 93-113. tion program. DBC Trans., p. 3. Geist, V. 1971. Mountain sheep, a study in behavior and evolu- Tsukamoto, G.K. 1979. Bighorn sheep status report - Nevada. tion. Univ. Chicago Press, Chicago, 383 pp. DBC Trans., pp. 107-108. . 1975. On the management of mountain sheep: Weaver, R.A. 1959. Effects of burro on desert water supplies. theoretical considerations. In J.B. Trefethen, ed. The DBC Trans., p. 1-3. wild sheep in modern North America. The Winchester Weaver, R.K. 1973. Progress at Aravaipa. DBC Trans., 117-122. Press and Boone and Crocket Club, New.York, pp. 77-105. Webb, P.M. 1979. Arizona bighorn sheep status report - 1979. Hailey, T.L. 1969. Status of transplanted bighorns in Texas DBC Trans., pp. 94-95. 1969. DBC Trans., pp. 80-86. Wilson, L.O. 1968. Distribution and ecology of the desert , R.G. Marburger, R.M. Robinson, and K.A. Clark. bighorn sheep in southeastern Utah. Utah Div. Wildl. 1972. Disease losses in desert bighorn sheep Black Gap Resour. Publ. 68-5, 220 pp. area. DBC Trans., pp. 79-83. , chairman. 1975. Report and recommendations of Hansen, C.G., T.L. Hailey, and G.I. Day. 1980. Capturing, the desert and Mexican sheep workshop group. In J.B. handling, and transplanting. In G. Monson and L. Surnner, Trefethen, ed. The wild sheep in modern North America. eds. The desert bighorn: its life history, ecology, and The Winchester Press and Boone and Crockett Club, pp. management. Univ. Arizona Press, Tucson, pp. 273-287. 110-143. Hernbrode, R.D. 1975. Aravaipa bighorn update-1975. DBC , J. Day, J. Helvie, G. Gates, T.L. Hailey, and Trans., p. 42. G.K. Tsukamoto. 1973. Guidelines for capturing and re-es- Jense, G.K., J.W. Bates, and J.A. Robertson. 1979. Utah big- tablishing desert bighorns. DBC Trans., pp. 137-154. horn sheep status report. DBC Trans., pp. 89-91. Winegardner, S.C., L.B. Dalton, and J.W. Bates. 1977. Cap- Kilpatric, J. 1975. Bighorn transplant in Texas. DBC Trans., ture and transplant of desert bighorn sheep with M-99. p. 38. DBC Trans., pp. 18-20. . 1976. Texas bighorn sheep reintroduction status Winkler, C.K. 1977. Status of the Texas desert bighorn pro- report. DBC Trans., p. 4. gram. DBC Trans., p. 4. . 1979. Texas reintroduction efforts status report- Yoakum, J. 1973. Survey of potential bighorn habitats on na- 1979. DBC Trans., p. 82. tional resource land in the southwest. DBC Trans., pp. McCutchen, H.E. 1975. Desert bighorn restoration at Zion 123-136. National Park. DBC Trans, pp. 19-27. . 1976. Status of Zion Natiohal Park desert bighorn restoration project. DBC Trans., pp. 52-53. . 1977. The Zion bighorn restoration project, 1976. DBC Trans., pp. 9-11. . 1978. Zion desert bighorn reintroduction 1977: project status and activities of released animals. DBC Trans., pp. 39-42. . 1979. Status of Zion desert bighorn reintroduction project - 1978. DBC Trans., p. 81. McQuivey, R.P. 1978a. The desert bighorn sheep of Nevada. Nevada Dept. Fish & Game Biol. Bull. 6, 81 pp. . 1978b. Bighorn sheep status report from Nevada. DBC Trans., p. 2-4. Monson, G. 1980. Distribution and abundance. In G. Monson and L. Sumner, eds. The desert bighorn: its life history, ecology and management. Univ. Arizona Press, Tuscon, pp. 40-51. Montoya, W., and G. Gates. 1975. Bighorn capture and transplant in Mexico. DBC Trans., pp. 28-32.

-28- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS water, vehicular access, and abundance of suitable habitat adjacent to the release site. Based upon these criteria, Goat EVALUATION OF A Mountain was a suitable release site. DESERT BIGHORN The release method was the subject of considerable debate. AGFD experience had been limited to projects in which RELEASE bighorn were kept in enclosures for considerable time periods before being released into the wild. Although funding for an enclosure had been secured through a cooperative agreement between the AGFD and the USFS, the success of releases James C. deVos almost immediately following capture of bighorn in Nevada William Ough (McQuivey and Pulliam, 1980) prompted a re-evaluation of the Daisan Taylor original plans. Because of the success of these and other Richard Miller releases, it was decided to use a release at Goat Mountain. Sandra Walchuk Richard Remington Bighorn were captured by darting from a helicopter. A Cap- Arizona Game & Fish Dept. Chur long range Projector and 3cc Cap-Chur darts were used. Phoenix, AZ Drug dosages were 2.5 mg of Etorphine (M-99) plus 20 to 25 mg of Azaperone (deVos and Remington, 1981). Bighorn were transported from the capture site to the base camp in a 9 foot square net. A metal ring in each corner of the net was con- Abstract. Twenty (7 rams, 13 ewes) desert bighorn were cap- nected to a 16-foot line attached to the helicopter when it was tured and transported from the Kofa National Wildlife Refuge loaded with a bighorn. Upon arrival at the base camp, animals and the Plomosa Mountains on November 10 and 11,1980. The were injected with a reversal dose of Diprenorphine (M50-50) bighorn were released after being held in a temporary holding and placed in a darkened horse trailer until transported to the facility overnight. Ewes have since moved short distances release site. from the release site and appear to have established use A 15 foot x 25 foot woven wire and burlap holding pen was con- areas. Rams have moved greater distances, but also appear to structed at the release site to limit post release "scattering". be staying in the general vicinity of the release site. Only one Bighorn were placed in this pen after dark on November 12, ram has departed from this pattern and on March 31, 1981 was 1980. The front of the pen was dropped for release at daylight several miles to the west of the release site. A minimum of 6 the following day. A11 of the bighorn were tagged with color- lambs were born in the release site during the spring of 1981. coded and numbered plastic ear tags. Two rams and 8 ewes were equipped with radio collars provid- Desert bighorn (Ovis canadensis mexicana and 0.c. nelsoni) ed by Telonics Inc., Mesa, Arizona to facilitate post release presently occupy a small portion of their historic range in monitoring of movements. Radio tagged animals were Arizona. Russo (1956) reported that bighorn populations in- monitored both from the ground and the air. habited mountain ranges from southwestern Arizona northward along the Colorado River into the Grand Canyon, with small remnant populations in the interior of the state. During the past 40 years, bighorn have been extirpated from several mountain ranges, i.e., the Santa Rita, Gila Bend, Saddle Moun- tain and others (Arizona Game and Fish Department, 1980). To reverse this trend, the Arizona Game and Fish Department (AGFD) initiated a program in 1957 to reintroduce bighorn into historic habitat. Weaver (1973) reported on the first bighorn transplant in Arizona. Sixteen bighorn were captured and released into a 112 acre enclosure in Aravaipa Canyon in southwestern Arizona. These bighorn were held in this pasture until their numbers had increased to 22, when a section of fence was removed allowing emigration on Jan. 8, 1973. The need for additional releases was recognized by many RESULTS biologists, and was officially identified by the AGFD in its Radio tracking began the day following the release. All of the bighorn strategic plan (AGFD, 1980). Since then several poten- radio equipped sheep were located on the first flight. One ewe tial transplant locations have been identified. travelled 1.4 miles the first day, with 6 of the 7 collared ewes The Virgin Mountains in northwestern Arizona was selected to (One ewe was injured during transport and was removed from be the second release site. Three rams and 9 ewes were cap- the area.) in the immediate vicinity of the release site. tured in the Black Mountains in November, 1979, and released Movements were greater for the 2 collared rams than for the into a large enclosure on the Virgin Mountains. ewes. The rams moved in different directions, and travelled 4.8 Two transplants were made in 1980. One involved the place- and 5.3 miles during the first day following release. Movement ment of 12 bighorn in a holding pasture in southeastern data are summarized in Table 1. Arizona. The second was the release of 20 bighorn taken from Bighorn movements were monitored almost daily during the 6 the Kofa National Wildlife Refuge, and released into the wild in weeks following the release. Maximum use areas were the vicinity of Goat Mountain on the north side of Apache Lake calculated from data collected during this time period. The in central Arizona. This release will be discussed in this report. calculated mean maximum use area for ewes was 1.7 miles2, METHODS and for the 2 rams was 1.9 mile& Selection of the release site was the result of investigations Movements from the release site were not extensive between conducted by AGFD and Tonto National Forest (USFS) November 12 and December 29, 1980. During this time, ewes biologists. Factors evaluated included: topography, degree of moved between 1.0 and 4.9 miles from the release pen with a forage degradation by domestic livestock, abundance of free mean maximum movement of 2.5 miles. Ram movements were DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -29- Table 1. Summary of bighorn movement from the Goat Mountain release site between November 13, 1980 and March 31, 1981.

Distance From Maximum Number of Animal Release Site Use Area Use Area Distance From Locations Number Sex 11-13-80 To 12-29-80 To 4-1-81 Release Site To 4-1-81

100 Ewe Release Site 110 Ewe Release Site 120 Ewe Release Site 130 Ewe 1.4 Miles 140 Ram 5.3 Miles 150 Ram 4.8 Miles 170 Ewe Release Area 180 Ewe 0.4 Miles 200 Ewe Release Area

'Maximum distance prior to movement of 3-31-81

more extensive, 4.9 and 8.5 miles for the 2 animals, or a mean The most recent (March 31,1981) aerial locations indicate that maximum of 6.7 miles. the 2 radio collared rams have made some movements. One Average daily movements were calculated when locations ram located within its normal use area northeast of Goat were obtained on consecutive days. Sample size for this Mountain on March 16, was located to the west of Goat Moun- parameter is limited, but some insight can be gathered. tain on March 31. This represented a movement of approx- Average daily movements for ewes was 1.0 miles daily, but on- imately 4 miles in 2 weeks. The other ram moved even further ly 0.74 miles daily for rams. during this 2-week period. It left its normal use areas east of Goat Mountain and moved approximately 19 miles to the west. Most of the movement data collected between December 29, In contrast, there have been no extensive movements by ewes. 1980 and April 1,1981, were from aerial locations, with minimal ground observation. Animals expanded their use areas during DISCUSSION this period. When all locations were used to calculate use It probably is too early to draw sound conclusions from the areas, additional explorations were apparent. Mean use areas data, but results to date indicate the release will be a success. for ewes increased from 1.7 to 2.4 miles2, increased propor- The center of most ewe use areas is less than 2 miles from the tionately. Maximum movement from the release site also in- release site. Establishment of use areas by ewes in close prox- creased, especially for rams. The maximum distance moved by imity to each other and to the release site are favorable indica- one radio equipped ram was 19 miles. Unsubstantiated reports tions of a successful release. Observations of breeding-age indicate that a young ram may have moved more than 30 miles rams either with or in close proximity to ewes also infers that to the west. If these reports are true, this animal moved across reproductive activities will occur during the upcoming a major highway. breeding period, which could be a key to success. Ground observations on December 17 and 18, 1980, indicated Some aspects of the data need further explanation. For exam- that the animals were in good physical condition and many ple, the smaller use areas for rams is a result of less movement adult ewes appeared to be gravid. Only one ewe was observed once they established their use areas. The higher average dai- with a ram and the others were either alone or with other ewes. ly movements recorded for ewes indicate that ewes required Radio locations after December 18, 1980 indicated that ewes greater areas than rams to fulfill their requirements. The top of were separating and moving to remote, rugged "lambing" Goat Mountain, where most ewes have centered their use areas. areas, is poorly watered in comparison with the area utilized The first evidence of reproduction was observed on February by the rams. Also, introduced ewes do not have established, 18, 1981. Three ewes (2 with radio collars and 1 without) and 3 traditional lambing areas and greater movements in search of lambs were observed. On February 19, a band of 5 ewes (3 with suitable lambing sites is probable. radio collars and 2 without) and 2 lambs were observed. Later The larger use areas established between December 29, 1980 that day, a band of 2 rams and 2 ewes were observed in close and April 1, 1981 probably resulted from ewes searching for association with the band of 5 ewes and 2 lambs. These 2 lambing areas and, subsequently, for nursery areas. groups may have been 1 loosely associated band. LITERATURE CITED A total of'17 bighorn were observed during the week of Arizona Game and Fish Department. 1980. Big game February 16-20, 1981. Twelve were from the original release strategic plans. Federal Aid Project FW-11-R-13, pp. 62-71. and 5 were their progeny. Radio locations also were collected for 3 additional bighorn. In all, 15 of the original 19 released deVos, James C., and Richard R. Remington. 1981. A summary sheep were accounted for. ot capture efforts in Arizona since 1977. DBC Trans., pp. 57-59. During the second week of March 1981, efforts to locate rams were- intensified. On March 10, 1981, 2 mature rams McQuivey, Robert P., and Dave Pulliam. 1980. Preliminary results of a wild-release desert bighorn sheep transplant were located. These animals were several miles to the east of rhe general area inhabited by the ewes. On March 11,1981, the in Nevada. DBC Trans., pp. 57-61. second radio collared ram was located to the northeast of Russo, John P. 1956. The desert bighorn sheep in Arizona. Goat Mountain. On March 12,1981, a single radio collared ewe Wildlife Bulletin No. 1. with a lamb was observed approximately 1.5 miles west of the Weaver, Robert K. 1973. Progress at Aravaipa. DBC Trans., area inhabited by the other ewes. pp. 117-122. -30- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS permanent water is available at various locations throughout ESTIMATING A the range (see Figure 1). Cattle have not grazed the Castle Domes for the past 25 years, and fewer than 25 burros present- BIGHORN POPULATION ly inhabit the area. Mule deer, although present, are not common. BY MARK-RECAPTURE METHODS A CO2charged Nel-Spot pistol capable of firing oil-base paint pellets was used to mark bighorn. Two marking flights were Robert C. Furlow conducted: one on October 26 and 27 using orange paint U.S. Fish and Wildlife Service pellets, and one on October 28 and 29 using blue paint pellets. Phoenix, AZ 85017 Two colors were used so that Bailey's (Caughley 1978) triple catch analysis could be used to compute the population Milton Haderlie estimate. Two recount flights were made: 1 on October 28 and Kofa National Wildlife Refuge 29 in conjunction with the second marking, and 1 on November Yuma, AZ 85364 12 and 13. Marking and recounting flights could not be evenly spaced due to conflicting deer and bighorn hunting seasons. Robert Van den Berge Table 1 summarizes the results of the 3 flights. Kofa National Wildlife Refuge Marking and recounting was done from a four-passenter Jet Yuma, AZ 85364 Ranger helicopter. Passengers included the pilot and recorder in the front and 2 markerslobservers in the rear. Sheep were marked from both sides of the helicopter, depending on terrain Abstract. Results of marking and recounting desert bighorn and which marker had the best shot. Most sheep were marked in the Castle Dome Mountains, Kofa National Wildlife Refuge, at a distance of feet or less. to obtain an estimate of population size are presented and the 50 validity of mark-recapture assumptions are discussed. Results Due to the extremely rugged and precipitous terrain, a grid pat- indicated a bighorn population of approximately 200. tern could not be flown. Instead, sheep were located by systematically searching all portions of the mountain range. All mark-recapture methods for estimating animal populations Approximately the same pattern of flight was used on both follow the same basic format. A sample of animals from a marking and recounting flights. Locations of marked sheep population to be estimated is captured, marked and released. are shown in Figure 1. Properties of this identifiable sample then are used to estimate the population (Caughley 1978). Sheep were marked on all parts of the body, including the horns. Some difficulty in seeing the paint marks on the recount Using marked animals to estimate population size was first advanced by Petersen (1896), but was not used until Dahl (1919) estimated the size of a fish population in this way. Lincoln (1930) used it to estimate duck numbers, and most wildlife biologists refer to the technique as the Lincoln Index. The name is unfortunate, because the method yields an estimate, not an index (Caughley 1978). It recently has been used to estimate wild burro (Equus asinus) populations in Arizona (Ohmart et al. 1978) and Nevada (Driver et al. 1979, Stoval et al. 1980) with apparent satisfactory results. Nevada uses a modified Lincoln Index for standardizing state-wide bighorn population estimates (McQuivey 1978). During October and November of 1980, a mark-recapture experiment was conducted with a bighorn (Ovis canadensis mexicana) population on the Kofa National Wildlife Refuge. The purpose of the experiment was to test the feasibility and reliability of mark-recapture to estimate bighorn numbers.

STUDY AREA The population estimate was conducted on approximately 115,000 acres (180 square miles) of desert bighorn habitat in the Castle Dome Mountains (Figure 1). The vegetation of the area is characteristic of the Upland Subdivision of the Sonoran Desert plant community (Lowe 1964). Mixed paloverde cactus associations (Cercidium-Cereus-Opuntia) are the most common features, along with numerous species of understory shrubs such as wolfberry (Lycium sp.), ratany (Krameria sp.), white brittle bush (Encelia farinosa), globe mallow (Sphaeralcea sp.), and others. The topography is extremely rugged, typified by extensive exposures of bedrock, sparse vegetative cover, lack of soil development, and steep slopes. Transitional areas of smaller mountains and slopes ("bajadas") are extensive. Elevations range from 1,000 feet on the valley floor to 3,788 feet atop Castle Dome Peak. Based on annual helicopter surveys during the past 10 years, the bighorn population has been estimated to be 150 to 250 Fig. 1. Study area and locations of marked sheep. animals. Bighorns utilize all portions of the Castle Domes, as Each dot represents 1 or more marked sheep.

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -31- Table 1. Summary of mark-recapture results.

Survey RAM CLASS Total Dates Hours Yrl. I II 111 IV Uncl. Rams Ewes Lambs Total

1st Marking 10126 & 27 Total sheep observed Number marked orange 2nd Marking, 1st Recount 10128 & 29 Total sheep observed Orange marks observed Number marked blue Total orange and blue marks in population 2nd Recount 11112 & 13 11.2 Total sheep observed 3 2 13 Orange marks observed 1 0 3 Blue marks observed 1 0 0 Total orange and blue 2 0 3 observed

flights was experienced and close observation, less than 100 DISCUSSION feet, usually was required. Fundamental to most mark-recapture methods are several RESULTS basic assumptions about the behavior of the individuals and Bailey's triple-catch method (Caughley 1978) was used to com- the nature of recaptures. The reliability of mark-recapture pute the population estimate. When time is limited, as was the population estimates depends primarily on the validity of case in this experiment, the triple-catch method provides a these assumptions; the grosser the violation of assumptions, quick, simple, and efficient method of estimation (Begon the less reliable the estimate will be. It follows then that 1979). The triple-catch method requires data from 2 marking assumptions are valid so long as they do not lead to results and 2 recounting occasions. The first recounting and second which are so unreliable as to be useless (Begon 1979). The marking use the same sample, so only 3 catches need be assumptions underlying Bailey's triple-catch method are as made. Data needed for a triple-catch estimate are presented in follows: 1) The probability of capturing an individual is the Table 2. same for both marked and unmarked and individuals in the population (equal catchability); 2) no births, deaths, immigrates, or emigrates in the study area between marking and Table 2. Data amenable to Bailey's triple-catch recounting; and 3) no marks are lost and are noted correctly on analysis. recounting. During the course of the experiment, a difference in the pro- Anlmais Animals examined Recaptures Recaptures bability of recapture between marked and unmarked sheep Time Marked for Marks from M, from M1 was believed to exist; e.g., marked sheep were less likely to be seen on recounting then unmarked sheep. This is probably due to the tendency of marked sheep, especially large, older rams, to hide from the helicopter rather than run. A decrease in the probability of recapture would result in N1 being overestimated. Unfortunately the degree of overestimation cannot be determined. Population size can be estimated from: Since the experiment was conducted after the critical mortality period (June-September), prior to the lambing season (January-April), and prior to long-range winter ram movement, data bias from births, deaths, immigrates, and emigrates Was considered insignificant. With a standard error approximately: When using paint pellets, there is a risk that some marks may be lost between marking and recounting, or that some marks may not be identified on recounting, especially on a poorly marked sheep. Ohmart et al. (1978) found that when wild burros were marked with the same type paint pellet used in this experiment, the marks became difficult to distinguish about 10 Where N1 is the size of the population at time 1. days after marking and could not be distinguished after 20 Using the appropriate data from Table 2, the equation yields a days. Paint marks on bighorn, however, remained visible for up population estimate of 201, with a standard error of 99 or 49% to 3 months (J. Witham, pers. comm.). This difference probably of N1. is due to the wallowing and dusting behavior of burros, which -32- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS e

has a tendency to obliterate paint marks. Within the time frame of this experiment, we do not believe any marks were lost, but are not sure thls is true. ABERRATIONS OF THE A major disadvantage of using paint pellets to mark sheep is TOOTH ARCADE that no 2 sheep can be marked exactly the same; a glancing pellet will leave a larger, more visible mark than a direct hit. AND MANDIBLE IN Not knowing the size of the mark or where it is located on the body of the sheep makes It necessary to examine each sheep DESERT BIGHORN SHEEP from different angles. This Is time consuming and while ex- amining one sheep for a mark, other sheep can easily escape from being examined. This happened on 2 occasions. This examination process also places additional stress on all sheep, as it may take several minumtes to examine each animal. Robert L. Glaze CONCLUSIONS Glaze Veterinary Clinic Kerrville. TX 76028 The mark-recapture technique described in this paper is not an ideal method with which to derive desert bighorn population Thomas D. Bunch estimates.The rugged habitat that they occupy, th difference Dept. of Animal, Dairy B. Veterinary Sciences In the probability of recapture between marked and unmarked Utah State Univ., Logan UT 84322 Individuals, the high cost of helicopter time, and the stress placed upon the sheep all tend to discourage use of thls Paul Webb technique. On the other hand, precise population estimates Big Game Supervisor, Arlz. Game B. Fish Dept. usually are not required for management of desert bighorn Phoenix. AZ 85000 populations. In this respect, the trlple-catch method may provide a quick, simple, and efflclent method of population estimation. LITERATURE CITED Begon M. 1979. Investigating animal abundance. Univ. Park Press. Baltimore, Md. 97 p. Abstract: Twenty-five (.20) of 150 desert bighorn ram mandibles from sheep (0. canadensis rnexicana and 0. c. nelsonij Caughley, G. 1978. Analysis of vertebrate populations, Chapt. endemic to Arizona, had varying degrees of dental anomalies. 10. John Wiley and Sons. N.Y., N.Y. 234 p. These anomalies are believed to result from abnormal wearing Dahl, K. 1919. Studies of trout and trout-waters In Norway. of teeth, which leads to drifting and malalignment of the tooth Salmon and Trout Mag. 16:16-33. arcade. Once the natural support system breaks down, foreign Driver. T., K. Detweiler, L. Pizatella, R. Baker, and J. Morgart. objects (products from foods) become wedged and compacted 1979. Clark County wild horselburro inventory. Unpub. between adjacent teeth causlng trauma to the gingiva and rept. ELM. Las Vegas District. Las Vegas, NV, 4 p. peridontia. This is followed by an invasion of oral bacteria. The Llncoin, F.C. 1930. Calculating waterfowl abundance on the disease is characterized by loosened, displaced or shed teeth; basis of banding returns. Cir. US. Dept. Agri. No. 118,l-4. and focal osteonecrosis of the mandible, with or without Lowe, C.H. 1964. Arizona's natural environment: landscapes fistuiization. Abnormal tooth wear occurs primarily with the and habitats. Univ. Arlz. Press, Tucson. 132 p. P2, P3, MI and M2 check teeth. McQuivey, R.P. 1978. The desert bighorn sheep of Nevada. Nev. Dept. of Fish and Game, Biol. Bull. No. 6, Reno. 81 p. Ohmart. R.D., J.E. Walters, R.R. Johnson, and E.J. Bicknell. INTRODUCTION 1978. On estimating burro numbers: a more reliable Allred and Bradley (1965) reported a high incidence of dental method. DBC Trans. 22:45-46. anomalies In desert bighorn sheep (Ovls canadensis nelson/) Petersen, C.G.J. 1896. The yearly immigration of young plaice from the Desert Game Range of Nevada. They observed exten- Into Llmfjord from the German sea. Rept. Danish Biol. sive necrosis of the molar series in ewes six years of age or Stn., 6:l-48. older and in rams ten years or older. The second premolar(f1rst Remington, R. 1980. Temporary marking of bighorn sheep. check tooth) was commonly absent. A possible cause for the Ariz. Game and Fish Dept. Memo. Region IV, Yuma. 2 p. necrosis of the tooth arcade was attributed to actinomycosis. Stoval, S., J. Morgart, and T. Combs. 1980. Wild burro inventory Similar dental aberrations have been observed In populations of the Virgin Mountalns and Grand Wash planning units of Arizona desert bighorn sheep (0. c. rnexicana and 0. c. and Lake Mead National Recreation Area, staff rept. ELM, neisonlj. Lower mandibles from several of these sheep were Ariz. Strip District. St. George, UT. 5 p. collected, and we here identify what we believe to be the prin- cipal cause and describe its associated pathology.

MATERIALS AND METHODS One hundred fifty mandibles collected from desert bighorn rams endemic to Arizona were examined for dental ir. regularities. Anomalies consisted of loosened, displaced or shed teeth and focal osteonecrosis of the mandible.

RESULTS AND DISCUSSION Lesions associated with dental aberrations and necrosis of the mandible in the desert bighorn from Arizona are not typical of actinomycosis lesions (Gibbons et al., 1970). Actinomycosis DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -33- Figures 1. and 2. lmpactlon of food between adjacent teeth allow mixed oral bacterial to enter the gingival Sulcus and to penetrate the parlodontal membrane.

Periodontal dlsease is initiated by foreign objects such as grass awns and stemmy or woody fragments, that perforate the glnglval membrane thus allowing for the Invasion of oral bacteria. Aberrant tooth arcades in the desert bighorn mandibles as characterized by loss of teeth. excessive orowth of other teeth and necrosis, appear to be by tie loss of the normal occlusal surface (table surface) of the teeth. Whenever this surface is examined, particularly as a sheep ages, the 2nd and 3rd premolars and the 1st and 2nd molars are seen to receive the majority of the wear. The incidence of dental irregularities in young sheep on the same diet as the older animals is considerably less. This wearing phenomenon reduces the natural structural support of the molar teeth. Once the support system is altered, several things may occur:

1. The teeth drift out of their natural alignment. 2. Improper occlusion causes further malallgnment. 3. Spaces formed between adjacent drifting teeth become reservoirs for compacted food particles. 4. Continued compacting of food creates a wedge effect that causes further displacement of teeth. 5. Since the alveolus (tooth socket) remains fixed, a void generally results in enlarged osteoid tlssue as a response to is created between the tooth and the bone. osteoplastlc inflammation and consists of thin trabeculae, 6. The peridontla and gingiva become inflamed from granulomatous tissue and coalescing areas of liquefaction trauma (impaction of food) and therefore susceptible necrosis. Granulomatous tissues often have fistulous tracts, to infection from oral bacteria. or sinuses, to the exterior of the mandible andlor may result in 7. The subsequent Infection results in abscessation with a cauliflower arrangement of the bone. These clinical signs or without fistulation and occurs long after the original were generally not evident in the desert bighorn ram man- problem of excessive tooth wear occurred. dibles. The orlncloal causes of tooth wear are soil fsiltl on ingested The dental aberrations of the mandibles examined In thls forade and the utilization of forage that is abresive and coarse. study are believed to result from abnormal wearing of the Another factor of less imoortance Is lmoro~ermineralization molar teeth, which eventually results in loosened, displaced or of the developing tooth (1.e. ca~diuideficiency or shed teeth and localized osteonecrosls of the mandible. The calciumlphosphorous Imbalance, which may be symptomatic sequela of the malady is similar to periodontal disease. of poor range conditions). During fetal development and Periodontal dlsease Is a necrotizing Infection of the gingival neonatal growth, improper mineralization will result in relative- membrane, which also results In displacement or shed teeth ly soft teeth that are subject to faster than normal wearing In and localized necrosis of the mandible (Jensen, 1974). the mature animal.

-34- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS Figure 3. Teeth that become worn andlor loosened will elther be expelled (2) or medially displaced (1).

Although the direct effects of this disease have not been assessed in populations of wild sheep, it contributes to the following: 1. Loss of ability to properly masticate, which is an essential part of digestion. 2. May serve as a port of infection to other parts of the body. 3. Failure to drink cold water or eat snow thus leading to dehydration. 4. Failure to utilize winter range forages properly. 5. Poor body condition, which may result in increased susceptibility to predation, reduced longevity and reduced reproduction. Twenty percent of the mandibles exhibited varying degrees of dental aberrations and focal osteonecrosis. Although we dealt only with rams in this study, tooth anomalies occur in female domestic sheep with equal or Fig. 4. Once a tooth is expelled the natural wedglng affect greater incidence than in the male. If the same is true in populations of wild sheep, the disease must have a confound- that holds the remaining teeth in alignment is no ing and deleterious effect on population growth as it limits longer operable. Consequently, a domino effect may production in the ewe. occur where several teeth are lost in a row. SUMMARY 1. Lumpy jaw is a catch-all name for enlargements of the jaw regardless the cause. 2. The majority of lumpy jaw problems result primarily from excessive tooth wear to the P2, P3, MI and M2 cheek teeth. 3. Tooth aberrations in the desert bighorn sheep result characteristically from excessive tooth wear (attrition) andlor abrasion from silt and coarse forage. 4. Tooth wear and range condition may be related in some cases. LITERATURE CiTED Aiired, A. and W.G. Bradley. 1965. Necrosis and anomalies of the skull in desert bighorn sheep. Trans. Desert Bighorn Council, pp 75-81. Gibbons, W.J., E.J. Catcott and J.F. Smithcors. 1970. Bovine Medicine and Surgery. American Veterinary Publications. Often associated with the necrotizing Infection is Inc., Illinois, pp 171-178. Fig. 5. localized osteonecrosis of the mandible adjacent to Jensen, R. 1974. Disease of Sheep. Lea and Febiger, Philadelphia, pp 211-213. the infected sulcus. DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -35- boundary (including the Mojave B Range to the southeast) encompasses over one million acres of the Mojave Desert, including the southeastern portion of the Coso Range, the western portion of the Argus Range, the southern portion of the Slate Range, and the entire Eagle Crags. Most of this area is Creosote Bush Scrub, Shadscale Scrub, and Joshua Tree Woodland, with Pinyon-Juniper Woodland at the higher elevations of the Coso and Argus Ranges. Much of the area includes the typical rocky precipitous terrain that we consider good bighorn habitat. METHODS James R. DeForge Joan E. Scott The Society's research team conducted field investigations in Glenn W. Sudmeier the NWC from June 1980 through December 1980. Field work Richard L. Graham was often limited to two or three day trips due to limited admit- Steuhen V. Segreto tance to the range by the Navv. Team members went 61 davs sodiety for th'iconservation of Bighorn Sheep in the field, totaling i65 man-days. Additionally the Navy fldw Upland, CA 91786-0710 team members by helicopter over the Argus Range. in order to survey some of

Abstract. Research conducted by the Society for the Conser- RESULTS AND DISCUSSION vation of Bighorn Sheep within theChina Lake Naval Weapons investigations indicate no sign of resident bighorn popula- Center, California, indicates that the resident populations of tions within the China Lake Naval Weapons Center today. desert bighorn sheep in the Eagle Crags and Argus Mountains Possible reasons for these losses based on observations dur- have disappeared. Possible reasons for these losses include ing the field studies are as follows. mining activities, competition from feral burros and horses, 1. Mining activities. predation, lack of water, diseases introduced from domestic livestock, and isolation and resulting inbreeding. Mule deer Signs of extensive mining around the turn of the century were are found in the study area, but probably were not limiting to evident throughout the study area except in the Eagle Crags. bighorn. The effects of military activities on the bighorn can- Mining camps were most often built on or adjacent to springs, not be evaluated due to limited admittance to the range. which probably limited the availability of water for bighorn. As these camps were often remote, the bighorn possibly provided a good food source to the miner, further limiting the occur- INTRODUCTION rence of sheep. When the NWC took control of this area in The Society for the Conservation of Bighorn Sheep is re- searching declining bighorn populations in an effort to better understand the causes of bighorn decline. Weaver and Mensch (1970) indicated that the populations of desert bighorn (Ovis canadensis nelsoni) in the Argus and Eagle Crags Moun- tains were declining and that the adjacent Slate and Coso h NEVADA Ranges only had transient sheep. Little was known of these bighorn populations, as these four ranges are within the boundaries of the China Lake Naval Weapons Center (Figure 1). Weaver and Mensch (1970) estimated twelve bighorn in the Argus Range and seven in the Eagle Crags. Navy personnel had seen sheep sporadically as recently as seven to eight years ago. However, the state of these populations, their numbers, and their ranges were not known. The many bighorn petroglyphs throughout the area indicate that sheep were numerous ihthis mountain chain prior to European man's first RIDGECREST SLATE RllNGE entrance. Public closure provlded a unique study area. Although the bighorn herds were reportedly declining, human encroachment into bighorn habitat and hunting or poaching were not expected limiting factors, as security within the Naval Weapons Center (NWC) was strict. Additionally, feral burros CALIFORNIA on the range presented an ideal opportunity to study the effects of competition. We thank the following people for their assistance in this project: Charles W. Jenner, D.V.M., Research Committee Chair- man; Tiily Barling, Natural Resources Officer, China Lake Naval Weapons Center; Loren L. Lutz, D.D.S., President, Socie- ty for the Conservation of Bighorn Sheep: Richard A. Weaver, W lo ife Manager Bio og st. &iiiorn a Department of F'sh and Game Aadit ona ly, we appreciate tne i nanclal sLpport of tne Foundation for North American Wild Sheep.

STUDY AREA The China Lake Naval Weapons Center was established in Figure 1. China Lake Naval Weapons Center (heavy 1947 and since that time has been closed to the public. Its outline). -36- DESERT BIGHORN COUNCIL 1981 TRANSACllONS 1947, all mining within their boundary was stopped. The only source from natural burro deaths, stillborn animals, etc. may significant mining today is on the eastern slopes of the Argus have increased the carrying capacity of these predators. On Mountains outside the NWC control. The impact mining may several occasions during this study, observation was made of have had on bighorn is unknown; however it most likely led to a the quick speed at which predators consume dead burros. reduction in bighorn numbers and suitable habitat, resulting in range isolation. 7. Water. Weaver and Mensch (1970) suggested that lack of water and 2. Burros (Equus asinus). competition for it with birds such as chukar (Alectoris chukar), This north African ungulate was brought into our Gambel's quail (Lophortyx gambelii), and mourning doves southwestern deserts by the miner and subsequently became (Zenaida macroura) may have limited bighorn in the Eagle feral. In early days miners and ranchers probably kept the Crags. During our investigations, water was found in all ranges number of feral burros in check. Today, with full protection, and was not a limiting factor. However, during times of the burro population has shown tremendous increases within drought, Mesquite Spring is the only viable water for wildlife in the NWC, now numbering between 4,000 and 6,000 (Tilly Barl- the Eagle Crags (Tilly Barling, personal communication). It is ing, personal communication). Burros are found throughout possible that lack of water in this range during dry years has the study area, with only the Eagle Crags showing limited use. lead to the bighorn's disappearance here. On many occasions over 100 burros could be observed from 8. Disease. one location. Habitat damage from burros, including heavy vegetation cropping, water hole damage, and extensive trail- It is generally accepted that diseases introduced by livestock ing, was found from the valley floor to over 8,000 ft. In the such as domestic sheep have been a major cause for bighorn Coso, Argus, and Slate Mountains, all water sources visited declines (Buechner 1960). Domestic sheep were grazed within were found to be impacted by burros. This destruction of the area of the NWC prior to 1947 (Tilly Barling, personal com- habitat by the burro was most probably a major limiting factor munication). Since then limited grazing of domestic sheep has on the bighorn. In early 1981 the NWC began a removal pro- been allowed in some of the more peripheral areas bordering gram on the burro population. probable bighorn habitat. Today cattle ranchers have permits to graze their herds within the boundaries of the NWC in both 3. Feral horses (Equus caballus). the Coso and Argus Mountains. Feral horses were observed in the Coso and Argus Ranges. In the late 19601s,Warden Vern Burandt found a dead bighorn When the Navy took control of this land, ranchers as well as lamb in the Saline Valley, just north of the study area (Dick miners were bought out. Some of these ranchers failed to Weaver, personal communication). The cause of death was gather all of their horses, resulting in the establishment of the diagnosed as contagious echthyma, or soremouth, a disease feral populations which exist today. Although the number of seen in domestic sheep and goats. Contagious ecthyma can wild horses (approximately 600; Tilly Barling, personal com- lead to debilitation and eventually death and has been found munication) is considerably less than that of the burro our in other bighorn populations in the state (Payson 1977, Jessup findings suggest that the horse does proportionately as much 1979). A disease such as contagious ecthyma could have lead damage to the range. Heavy vegetational and water hole to the decline of the bighorn in these ranges. damage in the Coso Mountains was observed in areas such as 9. Isolation and inbreeding. Water Canyon. Bighorn sheep in this area probably had more mobility in earlier years, permitting genetic exchange between herds of 4. Mule deer (Odocoileus hemionus inyoensis). these ranges and nearby ranges. Wifh increased obstructions Deer were observed in both the Argus and Coso Mountains. to movement such as roads, presence of man, and reduction Although deer may compete at times with bighorn for forage, of available water sources (due to mining activity, burros, and water, etc., no information was found that would suggest this drying conditions), populations most likely became isolated in- to have been limiting to the bighorn. However, it should be to small groups, producing a high rate of inbreeding. In- noted that deer sign was found in the Argus Mountains in breeding and the resulting lack of genetic variability reduces areas thought to have held sheep in times past. It does appear the ability to adjust to the constantly fluctuating environment. that mule deer have increased in this range, but this specula- Additionally, inbreeding can lead to a loss of immune tion is based on limited observations of deer in past years by surveillance, leaving the animals more susceptible to disease the Navy. and parasitism (DeForge et a/. 1979). The minimum size 5. Military activities. isolated bighorn population that could sustain itself is not The NWC in general is closed to the public at all times, but we known. were allowed entrance when the range was not "hot", i.e. when A combination of some or all of these factors may have lead to militarty testing andlor secret operations were not occurring. the loss of bighorn within this mountain chain, each with dif- Our observations indicate that public closure has helped to fering impacts in time and space, causing increased stresses preserve this land from outside human impacts. Ho~lever, on the animals and lowering the ability to survive. The since we were not present when the range was "hot", we can- sightings of bighorn seven to eight years ago may have been not evaluate the effects of military activities on bighorn. the last of a remnant population stressed and searching for a 6. Predation. more suitable environment. Man and his activities (roads, early mining, introduction of feral animals, grazing of livestock and An unusually large number of predators was seen in the NWC. subsequent introduction of new diseases) may in fact have Coyotes (Canis latrans) and bobcats (Felis rufus) were observ- had a great deal to do with the loss of these populations, even ed throughout the study area, and mountain lion (Felis con- though this area would seem free from human intervention due color) tracks were observed in the Joshua Flats area of the to public closure of the Naval Weapons Center. Coso Range. The ability of predators to kill bighorn sheep has been well documented (Smith 1954, Wilson 1968, Jorgensen The loss of the Argus and Eagle Crags herds adds two more and Turner 1975, McQuivey 1978, Wehausen 1979); however, ranges to the 14 in California where sheep have disappeared in their impact on bighorn numbers in unknown. The large the last third century (Dick Weaver 1979). This study further af- number of burros in the study area may have resulted in in- firms the delicacy and sensitivity of the bighorn and his en- creased numbers of predators. We do not suggest that burros vironment and the fine balance needed if we are to sustain are being killed by these predators, but the increased food sheep populations. DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -37- LITERATURE CITED Buechner, H.K. 1960. Bighorn sheep in the United States: its past, present and future. Wildl. Monogr. No. 4. 174 pp. DeForge, J.R., C.W. Jenner, A.J. Plechner, and G. W. Sudmeier. DESERT BIGHORN SHEEP 1979. Decline of bighorn sheep (Ovis canadensis), the genetic implications. Desert Bighorn Counc. Trans. IINTO COLORADO 23:63-66. NATIONAL MONUMENT Jessup, D. 1979. Statewide bighorn sheep disease research. Calif. Dept. of Fish and Game, Sacramento, CA. 9pp. Jorgensen, M.C. and R.E. Turner. 1975. Desert bighorn of the Anza-Borrego Desert State Park. Desert Bighorn Counc. Ronald R. Ravey Trans. 19:51-53. John L. Schmidt Department of Fishery and Wildlife Biology McQuivey, R.P. 1978. The desert bighorn sheep of Nevada. Colorado State University Nev. Dept. of Fish and Game. Biol. Bull. No. 6. 81 pp. Fort Collins, CO 80523 Payson, Joan B. 1977. A disease study of free-ranging desert bighorn sheep (Ovis canadensis crernnobates and Ovis canadensis nelsoni) in the Santa Rosa Mountains, Abstract. Eleven desert bighorn from Arizona were captured Riverside County, California. M.S. Thesis. Univ. of Wyom- as individuals and reintroduced into Devils Canyon, west of ing, Laramie. 42 pp. Colorado National Monument on November 8, 1979. This rein- Smith, D.R. 1954. The bighorn sheep in Idaho: its status, life troduction was followed by the release of 16 sheep from history and management. Idaho Dept. of Fish and Game Nevada into the monument on June 17, 1980. The Nevada Bull. No. 1. 154 pp. sheep had been captured in 2 groups and held in an enclosure prior to release. Radio transmitters were placed on 17 of the Weaver, R.A. 1979 Status of bighorn sheep in California. sheep (6 Arizona and 11 Nevada). Five known mortalities have Calif. Dept. of Fish and Game, Sacramento, CA. 7pp. occurred including 3 Arizona and 2 Nevada sheep. Reproduc- tion has resulted in at least 1 lamb in 1980 and 6 lambs in 1981. Weaver, R.A. and J.L. Mensch. 1970. Bighorn sheep in Winter weather restricted initial dispersal of the Arizona northwestern San Bernardino and southwestern lnyo sheep, possibly aiding in habituation to the release area and counties. Calif. Dept. of Fish and Game. Wildl. Manage. increased chances for social development. Good weather dur- Admin. Rep. No. 70-3. 17 pp. ing the Nevada release favored exploration by sheep with an Wehausen, J.D. 1979. Sierra Nevada bighorn sheep: an apparently existing social structure. Both releases have reduc- analysis of management alternatives. Cooperative project ed movements with most activity near Devils Canyon. Fre- of U.S. Forest Service and Nat. Park Service, Bishop, CA. quent interchanges between groups and the formation of 133 pp. nursery bands and a ram band are encouraging signs. Wilson, L.O. 1968. Distribution and ecology of the desert bighorn sheep in southeastern Utah. Utah Fish and Game INTRODUCTION Publ. NO. 68-5. 220 pp. Desert bighorn have been extirpated from much of their historic range throughout the West and Southwest due to man's encroachment and subsequent loss of habitat (Graham, 1980; DeForge,l972). Historical data including sheep skulls (Dalton and Spillett, 1971) and Indian petroglyphs (Stroh and Ewing, 1964) indicated that bighorn once resided in and around the area that is now Colorado National Monument (Denny, 1976). Buechner (1960) identified all of western Col- orado as historic sheep range and Monson (1980) stated that desert sheep once extended up the Colorado River from Utah into Colorado and the study area. However, Bear and Jones (1973), Cowan (1940), and Moser (1962) did not include the study area as historic range. Bauer's (1977) study in the Monu- ment suggested that desert bighorn could be successfully reintroduced to that area. Thus, in an effort to reestablish desert sheep into suitable habitat and probably historic range, a cooperative agreement was made in 1974 between the Col- orado Division of Wildlife, the National Park Service, the Bureau of Land Management, and the states of Arizona and Nevada. This agreement resulted in 2 transplant efforts. Eleven desert sheep (Ovis canadensis rnexicana) from the Kofa Game Range in southwest Arizona were reintroduced adjacent to Colorado National Monument in Devils Canyon on November 8, 1979. Devils Canyon was chosen as the original release site to minimize any potential human disturbance. A second release of 16 sheep (0.c. nelsoni), from the Lake Mead Recreational Area, Nevada, was made into Monument Canyon in Colorado National Monument on June 17, 1980. STUDY AREA The study area comprises approximately 670 km2, ranging from Grand Junction, Colorado, into eastern Utah (Fig. 1). The -38- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS . I POLLOCK CREEK CANYON

. MONUMENT

Figure 1. Extent of observed desert bighorn sheep range explored following reintroduction western Col- orado. Maximum range of Arizona sheep outlined with a dotted line; maximum range of Nevada sheep outlined with a dashed line.

area includes Colorado National Monument and the canyon tured lateral tendon in the left hind le'gduring the trapping country to the west. The area is geologically part of the Un- operation. After transport to Colorado, the injured leg was ban- compahgre Plateau and characterized by sandstone canyons daged and the other sheep inspected. All sheep were found to with steep talus slopes on canyon floors of Precambrian rock. be healthy and were airlifted to the release site in deer crates It is bounded on the north by the Colorado River and the Grand by helicopter. A helicopter mishap resulted in the loss of 2 Valley, a rich agricultural area, and on the south by Glade Park. adult ewes, but 16 sheep were successfully transported to the The area is considered a semiarid desert, with 28.3 cm average release site, including 4 rams, 7 ewes, and 5 lambs (3 males, 2 annual precipitation. Elevation ranges from 1370 m at the Col- females). All sheep were ear-tagged and collars placed on all orado River to over 2150 m on Black Ridge. but the 5 lambs. Radio-collars were placed on 4 rams and 7 ewes. At the release site, a 1 ha enclosure was used to hold the METHODS AND MATERIALS sheep overnight. The following morning a portion of the enclosure was opened and the sheep allowed ~LJfind the open- Twelve sheep from Arizona were captured as individuals by ing. In 20 minutes, the first sheep left the enclosure, followed helicopter. During transport to Colorado one adult ram died by the rest in the next 40 minutes. Table 1 gives a summary of from rhabdomyolysis, capture myopathy. Upon arriving in Col- release information. orado, the sheep were inspected : : found to have an infestation of the scabies mite, Psorpt i sp. As a result, the sheep Monitoring since release involved tracking primarily by radio were dipped in a solution of Linciane. A mixture of Lindane and signal both from the air and ground. Aerial telemetry positions mineral oil was applied in the ears. Because of the delay with were followed up by ground tracking and observations. Posi- dipping and because of the cold temperatures, the qiginal tioning by triangulation was generally not possible due to the plan to helicopter the sheep into an enclosure in Devils Can- inaccessibility of the area and difficulty in getting multiple yon had to be abandoned. The sheep were trucked to the locations. As a result, most signals were line-of-sight and mouth of Devils Canyon and released. There were 3 rams and 8 bounce signals. These can be used to locate a sheep in a par- ewes in the release. All sheep were ear-tagged and collared, ticular canyon or on a partkular canyon wall. Positioning by with 2 rams and 4 ewes receiving radio transmitter collars from radio signal alone, however, was only valid when confirmed by Telonics, Inc., Arizona. an actual observation. Changes in signal locations and obser- For the second release, 18 sheep were captured in Nevada in 2 vations were used to ensure accurate tracking and animal con- groups using a drop-gate panel trap. One ewe received a rup- ditions. Following an observation, location, behavior, and

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -39- other pertinent information was noted and plotted on an area the Monument approximately 6 km from the release site, the map. sheep began to explore primarily to the west, ranging into Utah - and north to the Colorado River. Apparently because of the RESULTS favorable weather with the June release, the Nevada sheep Movements. Following release in November of 1979, the have explored a larger area in contrast to the Arizona sheep. Arizona sheep immediately dispersed throughout Devils Can- Unlike the Arizona sheep, the Nevada sheep have explored yon. They explored the canyon as well as the rim and mouth of primarily in groups, ranging in size from 1 to 4 sheep. Frequent the canyon until winter weather reduced exploration. When interchange has also occurred between the Nevada groups. weather conditions improved in the spring, the Arizona sheep Although most have returned to areas near Devils Canyon, 2 began to explore areas outside of Devils Canyon, including ewes remain alone over 20 km southwest of the Monument canyons to the west as well as east to Colorado National Canyon release site. Monument. The sheep appeared to explore as individuals, with Mortality. Five known mortalities have occurred since the no interactions observed over the winter. The first observed first release. A 6-year-old Arizona ewe was found in early association occurred in late March of 1980 when a ram began January of 1980 mid-way up Devils Canyon on a series of traveling with a ewe north of the release site, near the Col- ledges. With the aid of a National Park Service technical orado River. climber, the carcass was examined on January 21,1980. Only a Except for exploring together, no interactions between the two partial necropsy could be performed with results inconclusive. were observed during the 1.5 months they traveled together. The ewe probably died within 1 month of release and may have The ram left in early May and explored areas to the west of been a post-release mortality as a result of the transplant Devils Canyon. Another ram moved through Devils Canyon to operation. During the necropsy, the ewe was found to be carry- the south rim shortly after release. He has remained above the ing a fetus. Fetal development indicated lambing would have canyons since release, exploring areas to the west and back. been in early March of 1980. The Nevada sheep remained near the Monument Canyon A yearling Arizona ewe was reported dead by a local rancher in release site for approximately 1 week after release in June of late August of 1980. He indicated the carcass had been 1980. With the exception of a young ram who has remained in discovered in early April. The ewe had been observed in good

Table 1. Summary of desert bighorn sheep (Ovis canadensis nelsoni and 0. c. mexicana) released in western Colorado.

Age (estimated Number of Number of Sex at release) Relocations Observations Remarks

Nov. 1979: Ria 25 lambed Mar. 1980, Apr. 1981 R2 40 lambed April 1981 R3 8 R4 1 died Dec. 1979 R5 28 R6* 18 lambed April 1981 Blue 8 0 Blue 9 7 lambed April 1981 Blue 11 0 Blue 12 4 died falllwinter 1980181 Blue 13 3 died April 1980 June 1980: R7 4 2 poached winter 1980181 R8 5 4 R9 3 11 R11 5 3 lambed April 1981 R12 3 1 lambed April 1981 R13* 2 9 R14 5-6 2 died fall 1980 R15 5-6 10 R17* 1 3 R18 2 9 Red 10 3 2 injured leg during capture 6 lamb 7 lamb 3 16 lamb 4 15 additional observations 17 lamb but lamb not identified 18 lamb 2

aR denotes radio collar 'radio collar failure

-40- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS condition several days before the death while associating with hind leg, but appeared healthy and able to move on the remain- a herd of approximately 700 domestic sheep near the mouth of ing 3 legs. This location is over 7 km from the Monument Can- Devils Canyon. The ewe apparently died shortly after the yon release site. domestic sheep were moved into lambing pens. Dogs were By late March of 1981, the Arizona ewe which had lambed in reported to be in the area at that time and may have been a fac- 1980 appeared pregnant and moved down from the west rim tor in the mortality. Because of the delay in reporting the mor- group into Devils Canyon and onto a high talus slope. Another tality, cause of death could not be determined. Arizona ewe was believed to be pregnant, but could not be A 6.5-year-old Nevada ewe was found dead in late November of located after her radio-collar failed in late March. Other ewes 1980. Her position had not changed for over 2 months after were suspected to be pregnant but could not be located or moving over 30 km west of the Monument release site into were in inaccessible areas. The first lamb was observed on almost inaccessible (to human) terrain in Utah. The area was May 1, 1981 with the Arizona ewe which had lambed in 1980. finally reached by raft in November of 1980. The partial The lamb was estimated to be several days old. skeletal remains were discovered on a high ledge above the A helicopter survey was conducted on May 19, 1981, to Colorado River. Cause of death could not be determined. estimate lamb production and was successful in locating 5 ad- A 5-year-old Nevada ram was poached over the winter of ditional lambs in 3 ewe-lamb groups. Three Arizona ewes were 1980-81. Signals during the fall of 1980 indicated movement located with 3 lambs mid-way up Devils Canyon, while another north across the Colorado River and later south of the river. Arizona ewe, her lamb, and a Nevada yearling formed another After the signal again showed movement north of the river, it group further up the canyon. Two lone Nevada ewes far west remained there for over 2 months. The radio-collar was of Devils Canyon were also observed with lambs. This results discovered with a bullet hole through it in late January of 1981. in a lamb:ewe ratio of 50:100, although 2 nonradio-collared It had been cut and hidden under a rock. It was uncertain Arizona ewes have never been seen, suggesting possible mor- whether the animal was poached north of the river indicating talities. With 10 ewes, the lamb:ewe ratio would be 60:lOO. A the ram had crossed the river, or south of the river with the newly formed ram band consisting of a yearling and adult poachers crossing to the north to dispose of the collar. The in- Arizona ram, and 2 adult Nevada rams was also found during cident is being investigated by the Colorado Division of the survey. Wildlife. A yearling Arizona ram was discovered on the same ledge area DISCUSSION as the first mortality during a helicopter survey in mid-May The Arizona sheep were captured as individuals with the 1981. This nonradio-collared ram had not been seen since July, assumption that the sheep were socially isolated, or had not 1980 when he had been observed on the same ledge area. This known each other prior to capture. After release, the sheep im- ram had been observed 4 times, always on the same ledge mediately dispersed. The Nevada sheep, in contrast, were cap- area. The carcass has not been examined. tured from existing groups. It is assumed that these sheep re- tained some form of group stability. Following release from an Reproduction and Breeding Behavior. Reproduction since enclosure they remained briefly near the release site before ex- release has resulted in a minimum of 7 lambs. One male lamb ploring in various sized groups. was born the first week in March of 1980 from an Arizona ewe Many factors influence sheep movements, including forage bred outside of Colorado. Breeding activity for the reintroduc- and water availability, topographical features, climatic condi- ed sheep in Colorado began with the observed interaction of tions, breeding activities, and the age and sex of individual the Arizona ewe and lamb with another Arizona ewe in early animals (McQuivey 1978). In this reintroduction effort, weather July of 1980. They began to move towards the head of Devils appears to be a major factor in initial dispersal of the Arizona Canyon when joined by another Arizona ewe to form a pre-rut and Nevada sheep by its effect on ease of travel and availabili- group. They were joined in late July by an Arizona and Nevada ty of food and water. In the November release, it appeared that ram. Frequent interactions were observed between all sheep, winter conditions including snow and cold may have been a including aggressive displays between rams, the male lamb, factor in restricting movements of the Arizona sheep to the and ewes. Although several mount attempts were witnessed, Devils Canyon area. Reduction of the exploring activity of the no actual mating was observed. newly released socially isolated sheep, due to weather Near the end of September, 1980, the group had relocated factors,increased the opportunity for encountering and interacting with other sheep, and may have aided in habituation several miles down Devils Canyon, closer to the release site. to the area. Movements increased in the spring of 1980 but The Nevada ram had moved west while another Nevada ram were primarily centered around Devils Canyon. Had weather and one of the Nevada lambs joined the group. Another of the Nevada lambs joined an Arizona ewe north of the release site conditions after release allowed favorable exploring condi- and outside Devils Canyon. By early October the group had tions, the sheep may have dispersed over a greater distance, moved closer to the release site in Devils Canyon and included increasing the chances for mortality and subsequent failure of the reintroduction. the Arizona ewe and lamb, another Arizona ewe, an Arizona ram, 2 Nevada rams, and 2 Nevada lambs. Only brief observa- If weather was a factor in the release of Arizona sheep, it tions were possible of this group. It is suspected that most would be expected that warm June weather for the Nevada breeding occurred in this group in September and October release would favor extensive exploring. Although summer while 4 other Nevada ewes remained far west of Devils Can- movements are generally restricted in the arid southwest due yon. to water availability (McQuivey 1978), the abundant forage and Movements over the winter were only slightly reduced due to water in the cooler environment of western Colorado favors ex- an unseasonably mild winter. By early March of 1981, most ploring. Extensive exploring may be undesirable for individual- sheep in Devils Canyon had moved to the west rim and formed ly released sheep, as this would likely decrease opportunities a group. This group included the Arizona ewe which lambed in for encounters during the breeding season. For sheep with an 1980, the Arizona ewe wh~chhad been north of the canyon, the existing social structure or group cohesion, however, it pro- Arizona and Nevada rams previously with the group, and 3 of vides the opportunity to explore large areas of suitable the Nevada lambs, now yearlings. Near this group were 2 habitat. The Nevada sheep did explore in various sized groups, Nevada ewes, including the ewe which had been injured during covering areas almost 40 km west of the release site and back. capture. The ewe had lost her canvas collar and use of the left Interchanges between groups and the breeding of 2 DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -41- far-ranging ewes suggests that group cohesion has been maintained. 1980 BIGHORN SHEEP The reintroduced sheep appear to be adapting well to their new environment. Interactions within and between releases STATUS REPORT has begun to increase. Nursery bands and ram bands were observed in the spring of 1981. These group formations and interactions are encouraging and hopefully will enhance the further development of a group structure, increase productivity James W. Bates and the likelihood of reintroduction success. Utah State Div. of Wildlife Resources Southeastern Regional Office 455 West R.R. Ave. ACKNOWLEDGEMENTS Price, UT 84501 Funding was provided by the National Park Service, the Na- tional Rifle Association and National Wildlife Federation. The Colorado Division of Wildlife provided valuable assistance in Financial problems within the state of Utah and budgetary many ways that included a 4 -wheel drive pickup truck, fixed- constraints within the Division of Wildlife Resources during wing aircraft time on numerous occasions, and a helicopter 1980 have severely limited bighorn sheep management pro- flight. Colorado State University provided facilities and exper- grams. Funds for aerial surveys and capital outlay for habitat tise of various kinds. Individuals too numerous to mention development were eliminated. The Utah Chapter of the Desert from both the National Park Service and Colorado Division of ~i~hornCouncil was informed that if trapping, transplanting, Wildlife have provided valuable assistance throughout the research and habitat development programs concerning the study. desert bighorn sheep were to continue, alternate sources of funding would have to be made available; however, the Utah State Division of Wildlife Resources management objectives LITERATURE CITED have not changed and will move forward as funds are made Bauer, M.R. 1977. The feasibility of reintroducing desert big- available. horn sheep to western Colorado. Professional Paper, The Division's management objectives are: (1) to increase Dept. of Fish. and Wildl. Biol., Colorado State University, knowledge of the life history, distribution, behavior, popula- Ft. Collins, Colorado. 57pp. tion and habitat requirements of desert bighorn as well as the Bear, G.D., and G.W. Jones. 1973. History and distribution of effects of human intrusion and activity, (2) to maintain the cur- bighorn sheep in Colorado, Part I. P-R project W-4143-22, rent distribution of bighorn by reducing impacts on present Job. No. 12. 232 pp. bighorn habitat and populations, (3) to expand the present Buechner, H.K. 1960. The bighorn sheep in the U.S., its past, distribution of bighorn into suitable and historic habitats present, and future. Wildl. Monogr. 4. 174 pp. through natural expansion and selected transplants, and (4) to Cowan, I. McT. 1940. Distribution and variation in the native provide increased opportunity for consumptive and non- sheep of North America. Am. Midl. Nat. 24505-580. consumptive use of bighorn sheep by increasing bighorn population. Dalton, L.B., and J.J. Spillett. 1971. The bighorn sheep in Utah-- past and present. Trans. First N. Am. Wild Sheep Conf. Alternate Financing: trapping and transplanting. In 1980 the 1 :32-47. Utah State Division of Wildlife Resources proposed for sale DeForge, J.R. 1972. Man's invasion into the bighorn's habitat. and sold a bighorn sheep permit for $20,000 to finance bighorn Desert Bighorn Council Trans. 16:112-115. sheep capturing and transplanting programs. This project was Denney, R.N. 1976. The status and management of bighorn consummated because Utah's bighorn population is currently sheep in Colorado. Desert Bighorn Council Trans. 20510. at a high in most areas east of the Colorado River, but is wan- Graham, H. 1980. The impact of modern man. Chapter 19, tonly lacking in many historical bighorn ranges west of the pages 288-309 in G. Monson and L. Sumner (Eds.), The Green and Colorado Rivers. The Division of Wildlife Desert Bighorn. The Univ. of Arizona Press. 370 pp. Resources' long-range plans have been to capitalize on high McQuivey, R.P. 1978. The desert bighorn sheep of Nevada. bighorn sheep populations through transplanting and hunting Nevada Dept. Wildl. Biol. Bull. No. 6. 81pp. before they crash from disease or parasites. Monson, G. 1980. Distribution and abundance. Chapter 3, The Division is desirous of transplanting surplus parent stock pages 40-51 in G. Monson and L. Sumner (Eds.), The into historically known bighorn areas in an, effort to Desert Bighorn. The Univ. of Arizona Press. 370pp. re-establish the species. Many of these areas have been void Moser, C.A. 1962. The bighorn sheep of Colorado. Colo. Div. of bighorn since the early p&t of the century. To date some 14 Wildl. Tech. Publ. 10. 49pp. release sites have been identified. The Division has become in- Stroh, G., Jr., and G.H. Ewing. 1964. Archeological survey of creasingly frustrated due to financial constraints and Colorado National Monument. Mimeographed report in escalating helicopter rental rates which have combined to cur- park files. Colorado National Monument, Fruita, tail the Division's transplanting program to a snail's pace. Colorado. 6Opp. Because of the remoteness of bighorn sheep habitat and rug- gedness of topography, the helicopter is an essential tool in locating, capturing, transplanting and releasing bighorn. Funds from the special permit in an amount equal to the license and regular permit fees were deposited as regular license and permit fee income. The balance was placed in the Contributed Research and Development Fund to be used ex- clusively for capturing and transplanting bighorn. Other funds for this effort were solicited and a contribution of $4,000 was made by Safari-Club International and $4,500 donated by the North American Foundation for Wild Sheep. -42- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS These funds were used for the purchase of a Simmons capture physiological and disease information from all sheep captured gun and 1,500 feet of drive net and the remainder was invested during the study. into helicopter time for the capture and release of bighorn. Sixteen bighorn have been captured in the park, fitted with The Simmons capture gun greatly facilitated our work since radio transmitters and are being followed to determine habitat the power could be adjusted quickly for distance from shooter preference and forage utilization. They utilized 38% grass, to sheep. Sheep mortality due to dart inflicted wounds was 45% shrubs and 17% forbs from July 1950 to March of 1981. almost eliminated. The distribution of bighorn within the park has expanded to include areas formerly used by domestic livestock, whose use The capture or drive nets worked well in areas in which the ter- was terminated in 1975. rain was adaptable to the operation. Rough, broken topograph was not suitable. (2) The second cooperative study between the Utah State Divi- sion of Wildlife Resources, Bureau of Land Management and Ten sheep (1 ram, 9 ewes) were captured in the drive net and 10 Utah State University was initiated in 1980. This doctorate (1 ram and 9 ewes) were captured with the Simmons capture study in southeastern Utah has as its objectives: (a) to study gun during January 1981. Twenty sheep were transplanted movements of bighorn on BLM lands, (b) to evaluate forage from San Juan County to the Kaporowitz Plateau in Kane utilization, (c) to study influence of recreation on bighorn, (d) to County. All sheep were released in good condition. study impact of domestic livestock on bighorn and (e) to ob- In addition to the sheep transplanted, ten sheep (1 ram, 9 tain disease and physiological information from all sheep cap- ewes) were captured and telemetered in Canyonlands National tured during the study. Seven bighorn have been captured and Park. Seven sheep (2 rams, 5 ewes) were captured and fitted with radio collars; however, field work will not get under telemetered in San Juan County. way until June of 1981. All sheep captured with the capture gun (27 head) were drug- (3) The third study is a cooperative project entered into by and ged with 2 cc M99 and.5 cc azaprone. Immediately after going between the Bureau of Land Management, US. Forest Service down M50-50 was administered to the sheep intravenously by and the Utah State Division of Wildlife Resources. The 3 agen- a veterinarian. The sheep were on their feet and going within 2 cies mutually recognize that desert bighorn and their habitats minutes. are a significant component of certain ecosystems within the state of Utah; that these areas of Utah are predominantly state Post-release observations of the Escalante sheep indicated land and are approximately 90% federally administered; that they were all alive and in good shape. After the release they much of this land is significant to desert bighorn as year-round moved out onto the canyon rims, but returned and settled in or seasonal habitat; and that information regarding critical the release near Navajo Point (the area anticipated by the field habitats and ecological requirements of bighorn is lacking and biologist). is vitally needed for inclusion in land use planning by all sections of society involved in land ownership, management or Population Trends. The Division was unable to conduct an planning. Therefore, it was mutually agreed that a jointly sup- aerial census this year due to budgetary constraints; however, ported and funded program be entered into to ascertain the general conditions of the herd were observed during trapping role of public and state lands in providing suitable habitat for flights. All sheep observed appeared to be in excellent condi- desert bighorn in Utah. tion. Sheep sign on the Potash Unit, South San Juan and on Canyonlands National Park indicated sheep densities were Starting May 15,1981, one employee was put on board who will about the same as the preceding year. Sheep sign on the provide assistance and information to graduate student and North San Juan Unit has been considerable less the last two personnel associated with the ongoing desert bighorn study years; however, the winters have been mild and the sheep have ~reviuslvmentioned between the Division, Bureau and Utah not had to move down out of the high country against the river. state university. He will monitor existing water developments We did conduct a pre-season classification on the North San and will identify, request and prioritize maintenance needs; Juan Unit by boat and observed 71 lambs per 100 ewes. Pro- identify all new springs, streams, ponds and other waters and ductivity looks good in the North San Juan Unit. determine their seasonal status and development opportunities; conduct periodic reconnaissance and documentation of seasonal bighorn movements, distribution and critical Sheep populations appear to continue to expand their range areas; provide assistance in bighorn capture and transplant- north up the Colorado and Green Rivers. Sheep are observed ing programs. further north and with greater frequency than during These three cooperative projects are an excellent opportunity preceding years. Sheep sign on the north side of the Colorado to update bighorn habitat development a:d management prac- River has been observed more frequently and one band of tices in southeastern Utah. seven head were observed in the Maze, a district of Can- yonlands National Park on the west side of the Green River. The Utan State Division of Wildlife Resources in cooperation Other sheep appear to be moving north along the Dirty Devil with Dr. Tom Bunch (Utah State University) will continue to and one herd of nine was reported near the Dirty Devil monitor the sheep herds for sinusitis, a disease that has been overlook. observed to a limited degree in southeastern Utah In the spring of 1980 one ewe (exhibiting clinical symptoms of Bighorn Sheep Research. The Utah State Division of. Wildlife sinusitis) was delivered to Utah State University for examina- Resources is currently participating in 3 cooperative bighorn tion and treatment. She responded to treatment briefly, but ex- sheep projects in southeastern Utah. pired to the disease within 3 months. As a method to study sinusitis, Dr. Bunch suggested we breed (1) A cooperative study between the Division of Wildlife a bighorn with a mouflon-argae cross to produce a sheep with Resources, U.S. Park Service and Utah State University. Field the horn structures of a bighorn and the ability to survive in a work for this master's project was initiated in July of 1980 in captive situation. Two rams were captured in 1980 on the the island part of Canyonlands National Park. The project is Potash Unit and forwarded to Utah State University. Semen jointly funded. was collected from these rams and the ewes were artificially Objectives for the study are to (a) study movements of the inseminated. There were no offspring produced from this pro- bighorn, (b) evaluate habitat utilization by bighorn, (c) deter- ject. One ram was returned and released on the Potash Unit mine the effects of human disturbance, and (d) to obtain and the other died as a result of a dislocated hip.

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -43- Plans are now under way to capture a sheep with clinical signs of sinusitis for a research facility where chronic sinusitis can ARIZONA be studied and perhaps a method of prevention or treatment can be formulated. BIGHORN SHEEP Habitat Development. The Utah Chapter of the Desert STATUS REPORT Bighorn Council sponsored a two-day field trip into southeastern Utah expressly for the purpose of performing maintenance on developed springs for bighorn. Their endeavor resulted in several developments being upgraded and put back Richard Remington into operating condition. Arizona Game and Fish Department Yuma, AZ 85364 The ELM also maintained several bighorn water developments in the Red Canyon Area in and adjacent to the Glen Canyon Recreation Area. These were springs developed several years ago by the BLM, but later incorporated into the Glen Canyon Abstract. A total of 2149 bighorn sheep classifed on ground Recreational Area. and aerial surveys consisted of 501 rams, 1103 ewes, 58 yearlings, and 487 lambs. Fifty hunters hunted 314 days and Bighorn Harvest. A 30 day season, September 13 - October harvested 39 rams for 78% hunter success. Research has 12, 1980, was authorized for the harvest of 18 legal rams in begun in Arizona to determine bighorn sheep and livestock in- Grand and San Juan Counties. Eight sheep were harvested for teractions in Arivapa Canyon. Research has also begun to 44% hunter success. This was a higher percent hunter suc- compare successes of enclosure and wild releases of bighorn cess than during previous years. in Arizona. A research project funded by electrical utility companies to assess impacts of power line construction and ex- istance on bighorn has entered its fourth year. Research funded by the Water and Power Resources Service on impacts of the Central Arizona Project on bighorn sheep movements entered its second year. Two transplants of bighorn sheep into historic habitat have occurred this year. A wild release was made at Goat Mountain in central Arizona. Bighorn were released into a 300 acre enclosure in the Galiuro Mountains. Bighorn are still present within the Virgin Mountain enclosure. Some 33 bighorn transplant sites have been identified within Arizona. Priorities are being established for future bighorn transplants within Arizona.

During 1980-81 bighorn sheep surveys conducted in Arizona produced a total of 2149 bighorn sheep observations. Bighorn sheep surveys were conducted both on the ground and with the aid of helicopters. Of the 2153 bighorn classified, 501 were rams, 1103 were ewes, and 487 were lambs. Also, 58 yearlings were classified. Calculated sex and age ratios are 45.4 rams to 100 ewes to 44.2 lambs. Surveys were conducted within 20 game management units, some with several mountain ranges, during the 1980-81 survey period. As in the past years, Arizona conducted a conservative bighorn sheep hunt. Statewide a total of 50 permits were authorized for the 1980 bighorn sheep hunt not including those authorized by the Hualapai Indian Reservation; this was a decrease of two permits from the 1979 bighorn sheep hunt. The 1980 permits issued were distributed over 19 hunting areas. The number of permits varied within each hunt area from 1 to 9 permits. A total of 2819 first choice applications were received by the Department for the 50 permits (not including the Hualapai In- dian Reservation); this was an average of 56 first choice applications for each bighorn permit. Total applications received by the Department for the 1980 bighorn hunt were comprised of 2230 resident and 589 nonresident applications. During the 1980 bighorn hunt a total of 50 hunters hunted 314 days and harvested 39 rams for 78% hunter success. As shown in the following table this is a lower hunter success than exhibited in the last several years. Range conditions were poor statewide during the 1980 hunt. Range conditions and water availability may have been partly responsible for the decrease in 1980 hunter success. Bighorn sheep were not necessarily present within their typical winter ranges during the 1980 hunt.

-44- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS elands experimentally in lieu of livestock grazing. A A Ten Year Summary of cooperative agreement was signed between the ranch and the Department allowing the AGFD to modify the enclosure and Arizona Desert Bighorn Sheep Hunting utilize it for bighorn sheep transplant purposes. Although the 1971 to 1980 fence was modified in an attempt to prevent bighorn escapes, 1 yearling ewe and 1 adult ewe escaped the enclosure shortly after their release. These 2 ewes, plus 1 lamb, were located ap- Percent proximately 9 kilometers south of the enclosure. In addition, to Hunter date 3 bighorn lambs have been observed in the enclosure. Year Permits Hunters Harvest Success Depending on the success of this lambing season, these 1971 85 81 31 38 bighorn may be released after the 1981 breeding season. 1972 74 74 35 47 Funds for the Galiuro Mountain transplant were obtained from 1973 71 68 38 56 the New Mexico Game and Fish Department (NMGFD). An 1974 63 62 41 66 agreement was reached between NMGFD and the AGFD for 1975 60 57 35 61 the capture of 24 desert bighorn, in which 12 bighorn were to 1976 61 61 46 75 be released into the Galiuro enclosure and 12 bighorn were to 1977 57 57 50 88 be transplanted to New Mexico. In 1980 12 bighorn ewes were 1978 58 54 45 83 captured in the North Plomosa and West Kofa Mountains of 1979 59 59 47 80 Arizona and transported by NMGFD to the Peloncillo Moun- 1980 50 50 39 78 tains of southwest New Mexico for their release into a paddock enclosure. Also in 1980, 8 bighorn were captured in the Black Mountains Ages of bighorn sheep harvested ranged from 4 to 13 years of northwestern Arizona and transported to Texas by Dr. Tom and averaged 7 years on a statewide basis. Green Boone and Bunch and Dr. Bob Glaze for continuing disease research. As a Crockett scores ranged from 135 618 to 175 418 and averaged result of these captures the AGFD has become concerned 156 218 from the 1980 bighorn hunt. about the health of the Black Mountain bighorn population. Continued monitoring of the health of this bighorn herd will be As an interesting note, Game Management Unit 31 was opened to bighorn sheep hunting for the 1980 hunt for the first time. necessary in the future. This unit includes the Aravaipa Canyon. This is the site of the A total of 20 Rocky Mountain Bighorn Sheep have been releas- Arizona Game and Fish Department's (AGFD) first bighorn ed in the Blue River area of eastern Arizona. In the spring of sheep transplant. Bighorn were transplanted into the Aravaipa 1979,2 rams and 6 ewes were released; during March of 1980,5 Canyon enclosure from 1958 to 1972. The herd grew to 22 rams and 7 ewes were released in the same location. Current- bighorn in 1973 when a portion of the fence was removed and ly, winter surveys produced sightings of 19 of the original 20 the sheep were released. Currently there are 60 bighorn sheep bighorn released. Also, during the 1980 helicopter survey, 6 estimated within the Aravaipa Canyon. Two rams were bighorn lambs were observed. The Rocky Mountain Bighorn harvested in this unit during the 1980 bighorn hunt. The rams are spending their summers at approximately 1980 meters harvested from Aravaipa Canyon scored 171 418 and 171 718 (6500 feet) in lower Blue River. Winter range of these sheep in- Green Boone and Crockett points and were aged 12 and 9 cludes the mixed conifer belt of the river canyons from 2430 m years respectively. to 2740 m (8000 to 9000 feet) of elevation. The New Mexico TRANSPLANTING PROGRAMS Rocky Mountain bighorn herd released near Glenwood, New Mexico appear to be expanding their range into eastern Arizona was very active during 1980 in capturing and Arizona. Bighorn sheep have been reported in the Salt River transplanting bighorn sheep. Two separate reintroductions of Canyon area of eastern Arizona, this is approximately 161 km desert bighorn sheep into historic habitat were conducted (100 miles) northwest of the Arizona Blue River release site. within the state this year. Bighorn sheep are still present within the Virgin Mountain During November of 1980, 20 bighorn, consisting of 13 ewes enclosure. Production remains good within the enclosure as 5 and 7 rams, were, captured in the West Kofa and North bighorn lambs were born by February 1980. One lamb was Plomosa Mountains of western Arizona. These bighorn were found dead. No cause of death was determined; the carcass transported to Apache Lake by trailer, then ferried across was mummified when found. In addition, one lamb was born Apache Lake by boat to their release site on Goat Mountain at within the enclosure in June 1980. This would mean the ewe the south end of the Mazatal Mountains of central Arizona. had to have been bred within the enclosure. At the present, 5 This is Arizona's first wild release of desert bighorn. Of the 20 lambs have been born within the enclosdre during March of bighorn captured, 19 were actually released at Goat Mountain, this year. Plans for their eventual release in 1981-82 are under 9 of which were fitted with radio transmitter collars. Monitor- way. ing of the released sheep indicates they have not n?civzdgreat distances from the release site and have segregated Within the state of Arizona the AGFD has presently identified themselves into 3 ewe bands, with rams mostly single or in 33 separate possible transplant sites and is in the process of pairs located around the periphery of the ewe band areas. To determining priority transplant areas and methods for the next date, 17 of the 19 bighorn released have been accounted for several years. As priority transplant areas are determined and and 6 bighorn lambs are known to have been born. planning with the land management agencies is completed, some bighorn sheep transplants may occur as early as the fall Also during November of 1980,12 desert bighorn consisting of of 1981. 9 ewes and 3 rams were captured in the Trigo Mountains of southwestern Arizona and released into an approximate 300 acre enclosure at the Mule Shoe Ranch located in the southern RESEARCH portion of the Galiuro Mountains (approximately 40 miles The AGFD has initiated a livestock-bighorn sheep interaction south of Aravaipa Canyon) of south central Arizona. This study in the Aravaipa Canyon area of south central Arizona. enclosure was constructed in the mid 1970's on the Mule Shoe During December of 1980, 10 bighorn were captured in the Ranch to raise elands. This was a private venture to raise Aravaipa Canyon area and fitted with radio transmitter collars

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -45- to begin gathering data on extent of habitat utilization, seasonal use areas, herd interchange, and movements. Data THE STATUS OF A obtained from this research will aid the Department and land management agencies in proper livestock stocking rates and TRANSPLANTED grazing practices that may have the least significant impact on bighorn populations. BIGHORN POPULATION Research has also begun in Arizona to determine the relative success of different types of bighorn transplants within IN ARIZONA USING Arizona. Monitoring of movements, extent of habitat utilization, and net production of bighorn will be compared from the AN ENCLOSURE Aravaipa Canyon herd, thevirgin Mountain, and Galiuro Moun- tain enclosures and the Goat Mountain release to determine the best transplant method of each of the priority release John R. Morgart sites. Bureau of Land Management 196 E. Tabernacle, St. George, UT 84770 Private and federally funded research projects involving bighorn are presently ongoing within Arizona. A bighorn study Paul R. Krausman initiated and funded by Arizona Public Service and Southern California Edison Electric utility companies is presently going Dept. of Renewable Natural Resources University of Arizona, Tucson, AZ 85721 into its fourth year. This research project was designed to determine impacts from powerline construction and post construction existence of a 500kv electrical transmission line throughout bighorn habitat in the New Water, Plomosa, Dome Abstract. In November 1979, 12 desert bighorn sheep (Ovis Rock Mountains, and the northern portions of the Kofa Game canadensis nelsoni) were captured in the Black Mountains, Range. A great deal of data on home range, seasonal Arizona and released in a 700 acre enclosure in the Virgin movements, and lamb mortality of bighorn have already been Mountains, Arizona. The introduced population included 2 documented from this research. adult rams, 1 yearling ram, 7 adult ewes and 2 yearling ewes. The purpose of the transplant is to create a breeding stock for In addition, a bighorn and mule deer movement study is reintroducing bighorn sheep into the Virgin Mountains. presently into its second year of research. This research project is being funded by the Water and Power Resources Ser- vice to determine movements of bighorn sheep and mule deer in relation to the Granite Reef Aqueduct portion of the Central INTRODUCTION Arizona Project near the Little Harquahala and Harquahala Mountains. Although only in its second year, data on seasonal Historically, bighorn sheep inhabited the Virgin Mountains, movement, herd interchange, and lamb production have been Arizona. Indian petroglyphs of bighorn sheep are present in documented. the Virgin Mountains and in adjacent ranges. Excavation of an archaeological site in the Virgin River Gorge uncovered the re- PLANNING mains of 7 sheep (Bureau of Land Management 1981). Inter- Since the passage of the Bighorn Sheep Strategic Plan by the views with long-time residents of the area indicate sheep were Arizona Game and Fish Commission in 1978, management common up to 1930. Illegal hunting and diseases may have planning for continuing research, transplants, and habitat im- been instrumental in their decline. Sightings of bighorn are oc- provement to Arizona's bighorn sheep will continue into the casionally reported in the Virgin Mountains and in the nearby future. Beaver Dam Mountains, however, they have been absent from the area as a viable population for 40 years. The reintroduction of desert bighorn in the Virgin Mountains was first considered in the early 1960's. In 1972, the Grand Wash Management Framework Plan (Bureau of Land Manage- ment 1972) recommended that studies be initiated for determining the practicality of reestablishing bighorn on the Arizona Strip. In 1974,the Black Rock Recreation Plan (Bureau of Land Management, 1974) recognized the unique wilderness character of bighorn sheep and the opportunities for reestablishment in the Virgin Mountains. During the public information phase of the plan, conservation groups supported the reintroduction of bighorn. In 1975, the Black Rock Habitat Management Plan was formulated. One objective of this document was "to provide suitable habitat in the Virgin Mountains for reintroduction of desert bighorn sheep." This plan was jointly written and approved by the Arizona Gaine and Fish Department and the Bureau of Land Management in 1976 (Arizona Game and Fish Dept. and Bureau of Land Manage- ment, 1976). In 1977 the AGFD and ELM inspected potential bighorn habitat in the Virgin Mountains to select a site for an enclosure. The location of the enclosure was chosen for its ability to meet the basic biological requirements of bighorn: cover, food and water. In addition, a remote area was needed to protect the sheep from human disturbance. A site on the western slopes of the Virgin Mountains was chosen as the most suitable location. -46- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS STUDY AREA rnonophylla), shrub live oak (Quercus turbinella) and buckwheat as dominant plants. Perennial grasses are com- The 700 acre bighorn enclosure is located 3 miles southeast of mon throughout the enclosure. Littlefield, Arizona, in T40N, R15W, Sections 23,24 and 25 (Fig. 1). The enclosure fence is a 5 foot high net wire topped by 3 MATERIALS AND METHODS strands of barbed wire spaced 1 foot apart (Fig. 2). Major On 12, 13, 14 ,November 1979, AGFD captured 12 desert drainages are fenced with swinging wooden panels (Fig. 3). bighorn in the Black Mountains, Arizona, for release in the These panels allow for free flow of water when flooding Virgin Mountains enclosure. Capture and transplant opera- without washing out the fence. In addition, a 2 strand electric tions are discussed by de Vos and Remington (1981). At the fence (Fig. 2) surrounds the enclosure. The purpose of the elec- end of each capture day, the sheep were transported by tric fence is to prevent entry by mountain lions (Felis helicopter (12, 13 November) or by horse trailer (14 November) concolor). to the Virgin Mountains study site and released. The introduced population included 2 adult rams, 1 yearling Two water storage facilities are inside the enclosure; both are ram, 7 adult ewes and 2 yearling ewes. All animals were tanks having a storage capacity of 5,000 gallons. One tank is ear-tagged and 6 (2 adult rams, 3 adult ewes, 1 yearling ewe) filled by water piped from a nearby spring, the other is filled by were radio-collared. tanker truck. The enclosure and water tanks were completed in RESULTS AND DISCUSSION January 1979. Movements. The first few days after their release in the The topography of the enclosure varies from wash bottoms enclosure, the sheep traveled the fence perimeter extensively. and rolling foothills to rugged mountains. Elevations range Testing of the fence with horn or hoof has not been observed. from 2,800 feet at the western end to 4,973 feet at the eastern After exploring the boundaries of the enclosure, the sheep set- end. The precipitous cliffs provide escape cover. tled down. The enclosure encompasses a wide range of eleva- Four general vegetatipn types are recognized. The wash tions and vegetation types. The upper elevations consist of vegetation includes desert peachbrush (Prunus fasciculata), rugged cliffs and are used for lambing and escape cover. Mormon tea (Ephedra spp.), snakeweed (Xanthocephalurn North-facing slopes are important in the spring and fall. The rnicrocephala) and cheesebush (Hyrnenoclea salsola). The more mesic conditions allow an abundant green-up of annuals Mohave Desert type is dominated by creosotebush (Larrea at these times. In addition, most cool-season perennial divaricata), cheesebush and burrobush (Ambrosia durnosa). grasses are located on north slopes. During summer months, The desert foothill vegetation includes ratany (Krarneria spp.), adult males are found in lower elevations of the enclosure. The brittlebush (Encelia frutescens), turpentine broom (Tharn- ewes and lambs occupy the desert foothills in the mid- nosma rnontana), Mormon tea, snakeweed, buckhorn cholla elevation range. (Opuntia acanthocarpa) and buckwheat (Eriogonurn Natality. An important measure of a transplant's status is fasciculaturn). The woodland-shrub type has pinyon (Pinus the birth of lambs. Of 9 ewes released in November 1979, 7

Figure 1. Location of the Virgin Mountains bighorn sheep enclosure on the Arizona Strip, Arizona.

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -47- -48- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS were potentially reproducing adults. Five lambs were born in trend. Clipping plots are read on a yearly basis to determine February 1980. The first was observed 13 February, the second annual plant biomass produced. on 22 February and the last 3 lambs were seen on 28 February. The Future. Definite plans for dates and methods of release A sixth lamb, born in March, died soon after birth of unknown of the bighorn sheep from the enclosure have not been for- causes. The seventh lamb was first seen on 12 June. Given a mulated. Alternatives include letting the population increase gestation period of 6 months (Monson and Sumner 1980), back- to 25-30 animals. Half of the herd would be captured and dating indicates this ewe was bred soon after being released released. The remaining half would stay in the enclosure and in the enclosure. The sex ratio of the surviving 1980 lambs is 3 build in numbers again. The process would then be repeated. A males and 3 females. All animals are healthy. second alternative is to allow the population to build to 25-30 In 1981, there is the potential for9 births. Five lambs were born animals and release the entire herd. The enclosure would be in March. The first was observed on 4 March, the following 3 on restocked with new animals and the process repeated. 25 March and the fifth on 30 March. At least 1 ewe is still preg- Long range goals of the transplant are to repopulate the Virgin nant. Mountains with a viable, self-sustaining population of desert Breeding Behavior. Most of the adult females were bred prior bighorn sheep. With the recent free-release of bighorn sheep to being placed in the enclosure. The adult rams freely in the Nevada portion of the Virgin Mountains by the Nevada associated with the ewes until February 1980, when lambing Division of Wildlife, this goal may be obtained in the near began. Between February and August 1980, the rams isolated future. themselves and were rarely seen in the company of ewes and LITERATURE CITED lambs. Beginning late August 1980, mixed sex herds were again common and this group association continued through Arizona Game and Fish Department and US. Bureau of Land March 1981. In March lambing began and the rams resumed Management. 1976. The Black Rock Habitat Management all-male groupings. Plan. Unpublished, in Arizona Strip District files, St. George, Utah. 15 pp. No dominance clashes were observed between adult rams dur- de Vos, J. and R. Remington. 1981. Bighorn sheep capture ing the breeding season. Geist (1971) observed in Rocky Moun- methods and results in Arizona. Trans. of Desert Bighorn tain bighorn sheep (0. c. canadensis) that recognition of size Council. 25: in press. seemed to be a factor in dominance relationships. The oldest Geist, V. 1971. Mountain sheep: A study in behavior and evolu- ram (3.5 years old when captured) outclassed the other 2 rams tion. Univ. Chicago Press, Chicago and London. 383 pp. (1.5 and 2.0 years old, respectively, when captured) in horn and body size and was dominant in all interactions. This may Monson, G. and L. Sumner. 1980. The desert bighorn: its life change as the younger animals mature. history, ecology and management. Univ. Arizona Press, Tucson. 370 pp. In 1980, at both the release site and capture site, the majority US. Bureau of Land Management. 1972. Grand Wash Manage- of lambing occurred in February (A. Fuller pers. comm.). In ment Framework Plan. Unpublished looseleaf (number of 1981, lambing was again common in the Black Mountains in pages varies), in Arizona Strip District files, St. George, February (A. Fuller pers. comm.). In 1981, however, lambing in Utah. the enclosure began in March. This shifting of the lambing season may be a natural consequence of one or more of the US. Bureau of Land Management. 1974. The Black Rock following: the age of the rams, disruption caused by the cap- Recreation Plan. Unpublished, in Arizona Strip District ture operation and acclimation to a different climatic regime. files, St. George, Utah. 14 pp. By comparing lambing seasons in the two areas over a period US. Bureau of Land Management. 1981. Cultural Resource of years, it may be possible to determine which factors are Overview. Unfinished manuscript, in Arizona Strip District files, St. George, Utah. Studies. A number of studies have been initiated in the enclosure. Fecal collections from known age and sex groups are made on a monthly basis. Fecal samples are examined microscopically to determine dietary composition. Not only will forage species present in the diet be identified, but seasonal variations in percent composition by sex and age class will be determined. In addition, adjacent to the enclosure monthly collections of domestic cattle (60s taurus) feces are made. Mule deer (Odocoileus hemionus) fecal samples are collected whenever encountered. Comparative analysis will give insight into interspecific competition for forage. Fifteen to 20 common plant species in the bighorn sheep diet are collected on a monthly basis for nutritive analysis. Phosphorus, calcium, carotene, gross energy, crude protein, ash, crude fat and carbohydrate levels are being determined. Phenological stages of approximately 75 plant species are quantified on a weekly basis. This list includes common range plants in the enclosure and common species in the bighorn diet. In addition, precipitation and temperature measurements are collected on a daily and monthly basis and correlated with plant phenology. Long-term studies have been initiated to quantitatively define vegetation inside and outside the enclosure. Permanent line transects have been established to obtain data on density, cover and frequency of plant species by vegetation type. Per- manent photo plots will provide data over time on vegetation

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -49- jects were partially funded by federal aid funds secured CONDllTlON AND TREND through the Pittman-Robinson Act. REPORT FOR THE 1980 HELICOPTER SURVEY RESULTS A total of 80.2 hours of helicopter survey time was expended SHEEP POPULATIONS during September and October of 1980 while surveying 12 ranges in the state that support bighorn populations. The IN NEVADA surveys resulted in the observation of 1,784 animals as compared to 1,403 sheep the previous year. The two year survey represented the actual observation of 2,271 individuals since several different ranges were sampled during the two year Robert P. McQuivey period. The results of the 1980 survey are presented in Table 1. Nevada Department of Wildlife Las Vegas, NV 89158 Annual helicopter inventories conducted in Nevada since 1969 and totaling some 13,081 observations are important for estimating herd numbers and trends of individual populations. Abstract. Intensive helicopter surveys of 12 mountain ranges An analysis of the recent data resulted in a current statewide in Nevada during September and October of 1980 resulted in population estimate of 4,654 sheep comprised of 2,444 ewes, observation of 1,748 bighorn with a ratio of 63 rams and 32 1,483 rams, and 727 lambs. These figures further suggest that lambs per 100 ewes. The 1980 hunt in the state resulted in the 48.8 percent of all the bighorn in the state were actually reported harvest of 66 rams which represented a 1.4 percent observed during the past two years. reduction in the estimated statewide population of 4,654 The observation rate of bighorn sheep during the 1980 census animals. Transplant efforts during summer months of 1980 was 21.8 animals per survey hour as compared to the previous resulted in the removal of 40 bighorn from the River Moun- five year average of 15.6 observations per hour. The higher tains; 18 were relocated to the Colorado National Monument than normal rate of sightings was a result of several indepen- and 21 reintroduced into the Virgin Mountain Range of Clark dent factors that included the following: continued higher than County, Nevada. Although most individual populations in the normal densities in those areas surveyed, concentrations of state appear to be healthy and at high density levels, a few in- sheep near water sources because of unseasonally warm dividual herds are showing an increase in the occurrence of temperatures and dry climatic conditions, and because of in- psoroptic mites. Recent data from the Mormon Mountains creased familiarity of the observers with the terrain and habits also show that bronchial pneumonia has resulted in abnormal- of sheep in those areas surveyed. ly high losses to this population. The observed ratio of 63 rams per 100 ewes in the sample is within the norm documented for the statewide population Primary objectives of the desert bighorn sheep program in since 1969. The estimated age class structure has also been Nevada during the past year included the continuation of a stable for the past five years with 39.9 percent of the rams be- population monitoring program by means of intensive aerial tween one and three years of age, 35.9 percent between four surveys, attempts to increase distribution and numbers by and six, and 24.2 percent seven years old and older. These data means of trapping and transplanting, and the continuation of show that most bighorn populations in the state are stable or a closely controlled harvest management program. These pro- slightly increasing at abnormally high density levels.

Table 1. Record of desert bighorn sheep observed during September and October of 1980 as a result of annual helicopter inventories.

Survey Total Number Number Number Ratio Mountain Range Time Observations of Ewes of Lambs of Rams RamlEwelLamb

Monte Cristo Range Silver Peak Range Lone Mountain Stonewall Mountain Spring Range North Eldorado Range South Eldorado Range . River Mountains Mormon Range Black Mountains Muddy Mountains Pintwater Range Sheep Mountains

TOTALS 80.2 1,748 897 289 562 6311 00132

-50- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS Table 2. Record of Mormon Mountain bighorn obsenrations as documented during annual October inventories.

Survey Total Number Number Number Ratio Year Time Observations of Ewes of Lambs of Rams RamlEwelLamb

27 8211 00176 44 9811 00153 66 1001100131 75 8211 00138 107 8211 00139 88 8311 00142

TOTALS 53.5 1,082 474 201 407 8811 00147

THE MORMON MOUNTAINS SITUATION nonresident tags. The number of applications ranged trom a One population of desert bighorn that appears to have suf- low of 17 resident applications for three tags in one area to a fered an unusually high amount of mortality during the past high of 78 nonresibent applications for one tag in another hunt year is located within the Mormon Mountains of Lincoln Coun- unit. ty, Nevada. Although individuals within the population ap- A total of 66 bighorn rams was reported harvested in Nevada peared healthy and a normal sample was obtained during the during the 1980 season for a success rate of 76.7%, or 88.9% October 1980 aerial survey, hunters in the area reported find- nonresident success and 75.3% resident success. The ing 35 fresh carcasses between November 1 and December 15. average success since hunting was initiated in 1952 now Tissue samples collected from five individuals in the herd and stands at 40.3% whereas the average success for the past five analyzed by the Veterinary Science Department at the Univer- years is 72.8%. The 1980 harvest represents the highest sity of Nevada at Reno suggested that the primary problem is number of rams ever taken during a single season and brings associated with chronic bronchial pneumonia. Although con- the total number of rams harvested in the state to 865. ditions that caused the pneumonia and the extent of mortality to date is not fully documented, a few conclusions can be The average age of rams harvested during 1980 was 7.4 years drawn from the information on hand. which is comparable to the average age for the past 5 years. Ages of rams in the harvest ranged between 3 and 14 with Survey records from the Mormon Mountains show that the 43.9% of the animals under the age of 7 years. Two young population increased significantly on an annual basis between rams did not meet Boone and Crockettrequirements and were 1974 and 1980 as a result of above average lamb production subsequently seized, whereas a total of 12 animals scored and survival (Table 2). The November 1980 population estimate enough points to be considered for the Boone and Crockett for the range was 462 sheep or 4.8 bighorn per square mile of Book (168 points minimum). The 1980 season also marked the available habitat, one of the highest densities in the state. first year that a bighorn sheep in Nevada was harvested with These data suggest that the Mormon Range herd was prime bow and arrow while an additional ram was taken with a for some type of population reduction because of the above muzzleloader. average herd level. A total of 83 hunters reported expending 621 days while observing 3,499 bighorn sheep for an average of 42.2 sheep per An additional survey was conducted on the Mormcn Range hunter and 5.6 bighorn pqr hunter day of effort. During the 1979 during February of 1981 in an attempt to assess the condition season, hunters reported observing an average,of 40.8 sheep of the herd and to document the approximate loss to the per hunter and 5.2 sheep per hunter day of e;iort. The reported population. During 10.2 hours of survey only 104 bighorn were ratio from hunter observations during 1980 was 82 rams and 26 observed with a classification of 55 ewes, 40 rams, and nine lambs per 100 ewes, which is comparable to hunter report data lambs or a ratio of 73 rams and 16 lambs per each 100 ewes. An from the past several years. Recommendations for the 1981 estimate of ram ages during the February survey also in- season in Nevada are similar to the past several years with the dicated that 77.3 % of the population was less than 4 years of exception of a closed season on the Mormon Mountain Range. age, whereas the October 1980 survey showed a much better stratified age structure in the herd. These data suggest that TRAPPING AND TRANSPLANT EFFORTS over 50 percent of the Mormon Range herd was lost d-uring the past 6 months with a majority of the mortality occurring The Nevada Department of Wildlife in cooperation with other among the very young (lambs) and very old animals. The condi- agencies is continuing with an aggressive program aimed at tion of the herd will continue to be monitored during the next reintroducing all 3 subspecies of bighorn sheep into their year. former ranges. Accomplishments during the past year include the release of California bighorn into the Granite Range of HUNTING AND HARVEST TRENDS northwestern Nevada, the release of Rocky Mountain bighorn Interest for hunting bighorn in Nevada remains high as in- into the Wheeler Peak area of the Snake Range, the release of dicated by the number of applications received for available additional desert sheep into the Virgin Mountains of southern tags. A total of 1,141 applications were received for the 77 resi- Nevada, and the transfer of desert sheep to the state of Col- dent tags, whereas 533 applications were received for the nine orado for release into the Colorado National Monument. DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -51- With respect to the desert sheep program, a total of 40 animals were removed by cooperative agreement with the National HISTORY AND STATUS Park Service from the River Mountain herd during the summer months of 1980. Eighteen of the animals were trapped at the OF BIGHORN SHEEP IN Southern Nevada Water Project using the drop gate panel trap and subsequently transported to Grand Junction, Colorado. THE GUADALUPE Animals captured on the first day of trapping were held in the transport truck for approximately 48 hours before being releas- MOUNTAINS, ed. All of the bighorn arrived in Colorado in excellent physical condition. NEW MEXICO The second phase of the River Mountain trapping project resulted in the capture of 21 bighorn (in addition to one trap mortality) that were transplanted to the Virgin Mountain Range as a supplement to 21 sheep that were reintroduced into the Bruce L. Morrison area the previous year. These animals were taken at the Na- New Mexico Dept. of Game & Fish tional Park Service horse corral area by means of a drop net Roswell. New Mexico trap baited with apple pulp. Details of this project that include the initial follow-up records are presented in another section of this publication. Abstract. Desert bighorn sheep (Ovis canadensis mexicana) have inhabited the Guadalupe Mountains of New Mexico and Texas since before man first ventured into the area. Indian rock art sites from the Guadalupes and surrounding mountains depict bighorn sheep. Since the advent of white man, written records indicate that bighorn were present. Mention is made of "mountain sheep" in numerous accounts of early ex- plorers and surveyors. Around the turn of the century, Vernon Bailey began his work in the southwest and collected the type specimen of the Texas bighorn (0.c. texiana) from the Guadalupe Mountains. Other biolgists conducted surveys and investigated reports of sheep sightings. The last documented report was in 1946. Desert bighorn were believed extinct in the Guadalupe Mountains by 1955. In 1979 photographs were taken of 2 bighorn sheep in the Guadalupe Mountains. These are believed to be migrants from the Sierra Diablo Mountains in Texas. Future plans call for the reduction of the aoudad (Ammotragus le~ia)population in the area and for the reintroduction of desert bighorn into their historical range.

INTRODUCTION The desert bighorn has occupied the Guadalupe Mountains of New Mexico and Texas since prehistoric times (Harris and Mundel, 1974). Once abundant throughout the mountain range, it was thought to be extirpated from the area in the 1950's (Simpson and Leftwich, 1976). A recent evaluation (Sandoval 1979b), indicated that a large portion of the range was suitable bighorn habitat. In light of this evaluation and of a recent, confirmed sighting of bighorn in the area, an evaluation was made of the past status of desert bighorn in the Guadalupe Moun- tains. The information gathered is a result of an exhaustive search of available literature, federal agency files, and New Mexico Department of Game and Fish files. STUDY AREA The Guadalupe Mountains are located in parts of Otero, Chaves. and Eddy counties of southeastern New Mexico and portions of Hudspeth and Culberson Counties of western Texas. The mountain range was formed 225 to 280 million years ago during the Permian Era (Barnett, n.d.). Shallow water near the shore of a 10,000 square mile inland sea provided the environment for lime-secreting algae to form a barrier reef (Newell, 1953), the remains of which form the Guadalupe Mountains. The topography of the range is characterized by an abrupt rim on the southeast and west sides with the southeast side bisected by numerous precipitous canyons, some measuring 610 rn (2,000 ft.) from rim to bottom. Climate is characterized by low rainfall, warm summers, and -&,+$LA..- 5 mild winters with yearly precipitation averaging 35 to 46 cm. (14 to 18 in.). Vegetation of the area is typical of the Lower Sonoran, Upper Sonoran, and Transition Life Zones with -52- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS mountain mahogany (Cercocarpus rnontanus), desert From 1955 to 1960 there were scattered reports of bighorn ceanothus (Ceanothus greggi), lechugilla (Agave lechugilla), sightings (Gross, 1960) but most of these were thought to be creosote (Larrea tridentata), and pinyon pine (Pinus edulis) be- aoudad sightings with the uninformed mistakenly calling them ing some of the more common species (Barnett, n.d.). bighorns. In 1960, R.E. Rea of the U.S. Forest Service reported BIGHORN OCCUPANCY seeing 2 rams on the north end of the Guadalupes. In 1976,2 local ranchers reported separate sightings of single animals Prehistoric: The Guadalupe Mountains have been utilized by on the south end. Although these reports could have also been humans for approximately 12,000 years. The earliest cultures aoudads, they were made by persons who should know the dif- were simple, nomadic lndians that utilized the numerous ference between the 2 species. caves in the region for shelter (Katz, 1978). Although not common in the Guadalupes, rock art sites give an indication of the Wildlife biologists from Texas Tech University observed and presence or absence of various animals. The Jornada style pic- photographed 2 bighorn sheep in May of 1979 in Little Dog tograph sites within the Guadalupe, Cornudas, and Hueco Canyon on the north end of the mountain range. This was the Mountains depict bighorn sheep in various forms (Schaafsma, first confirmed report since District Warden Simmons picked 1972). Although there is only one known depiction of bighorn up a skull in 1946. Mr. Paul 'Hedrnandez, while hunting at Pine Springs Canyon in the Guadalupe Mountains, it is aoudads in November 1979, reported observing 14 bighorn (10 believed that the numerous depictions in the Cornudas Moun- ewes and 4 rams) in Pup Canyon. This sighting was approx- tains, New Mexico, and at Hueco Tanks, Texas were made by imately 5 miles north of the May 1979 observation. Mr. Her- the same bands of prehistoric lndians that roamed the nandez had observed aoudads in the Hondo Valley on Guadalupes (Rammage, pers. comm.). numerous occasions and could correctly identify numerous pictures of both species (Sandoval, 1980a). His report is uncon- During the later part of the prehistoric period the Mescalero firmed but highly probable. Apache lndians used the Guadalupes as a hunting ground. The Two other questionable reports have been received since 1979. numerous images of bighorn sheep found at rock art sites in One was a report of 2 rams on the north end of the mountain the Three Rivers area of the Sierra Blanca Mountains may be range. The observer professed to have pictures of the sheep depictions of hunting trips into the Guadalupes (Rammage, and promised to show them to us after they were developed. pers. comm.). Although these rock art sites do not give us an When this person was contacted a few weeks later, his only indication of abundance of bighorn sheep, they do tell us that statement was that he did not want to talk about it anymore the early inhabitants knew of the bighorn and successfully (Brooks, pers. comm.). In November 1980, a 17-year-old hunter hunted them. reported seeing a ram in Little Dog Canyon. He was hunting Historic. Because of their distance from centers of com- aoudaa at tne time and did not shoot this animal because, in merce and development, the Guadalupe Mountains were not his words, "its horns made a circle instead of a curve" explored to the extent of other mountain ranges during the (Williams, pers. comm.). Although this report is unconfirmed, it time New Mexico was being settled. The earliest record of may have been a bighorn, as sighting occurred within % mile mountain sheep in the area was made in 1849 by Captain Ran- of Mr. Hernandez' observation. dolph Marcy when he led a U.S. Army expedition into the Guadalupes (Hollon, 1955). In his reports on the expedition, Current Status. The current status of the bighorn sheep in the Guadalupe Mountains is unknown. It is believed that a Captain Marcy mentions that mountain sheep were occa- sionally shot to feed the troops. small group of sheep are utilizing the mountain range. When tha 1979 reports were received, an effort was made to locate Jacob Kuechler was hired in 1878 by the Texas and Pacific sheep in the area. A Game and Fish Department biologist Railroad Company to survey railroad lands in the area. Kuechler reports that the canyons of the Guadalupes provide impenetrable haunts for mountain sheep and other animals that inhabit the mountains (Bowden, 1975). In 1900 it was Table 1. Guadalupe Mountains bighorn sheep popula- estimated that approximately 300 sheep occupied the tion estimates and sightings. Guadalupes (Roberts 1938, cited by Snow and Zimmerman 1939). In 1902 Vernon Bailey collected the type specimen of the

Texas bighorn near the New Mexico-Texas border (Bailey, Numbers1 1905). Bailey classified his specimen as 0.c. texiana but this Date Composition Location classification was later changed to 0.c. mexicana by Miller Source and Kellog (1955). 1900 300 northeast arm of mountains Manly Roberts 1914 100 general Guadalupe Mtns. From 1914 to 1928, various authorities estimated the de Baca 1916 100 generai Guadalupe Mtns. J.S. Ligon Guadalupe bighorn population to be approximately 100 sheep 1926 100 general Guadalupe Mtns. Vernon Bailey (Ligon, 1927; Bailey, 1928; Bailey, 1931). Few reports were 1939 4 Texas Guadalupe Mtns. Snow & Zimmerman received of bighorn sightings from 1928 on. In 1938 a joint 1939 4 hybred lambs Hughs Ranch, Dog Canyon Snow survey of the mountain range was made by members of the 1940 1 dead ewe McKittrick Canyon Ben McCollum U.S. Biological Survey, the U.S. Forest Service, the New Mex- 1942 1 Hepier Ranch, Dog Canyon Woody Hughes ico Department of Game and Fish, and the Texas Game, Fish 1942 1 Dog Canyon-West Rim Mrs. Sam Hughes and Oyster Commission. This survey resulted in the sighting of 1943 0 general Guadalupe Mtns. J. Ligon & 0. Mde 3 bighorn sheep, but members of the survey party felt that 1956 7 Smith Canyon, Texas portion unknown there was stiil a nucleus herd present (Barker, 1938). The 4 1956 20-c "a little bit further west" unknown agencies hired Robert Snow and Earl Zimmerman to conduct 1959 20t Dark Canyon Cliff Baumeister an extensive survey of the area in 1939. During a four-month- 1960 2 mature rams Panama allotment-West Rim R.E. R-ea period 4 sheep were observed in the Texas portion of the 1976 1 unclassified Dark Canyon Hugh ~i&aid Guadalupe Mountains (Snow and Zimmerman, 1939). 1976 1 ewe West Rim M. Hughes In 1946 a bighorn skull was found south of Hope, New Mexico 1979 2 ewe & lamb Little Dog Canyon Tony Dickinson and the District Warden reported that one more ram was still 1979 14 10 ewes4 rams Pup Canyon Paul Hernandez using the Penasco Canyon area (Simmons, 1946). Buechner 1960 2 rams Builis Lake Paul Brooks (1960) stated that bighorn sheep were extinct in the Guadalupe 1960 1 ram Little Dog Canyon Lester ;Jiliiams Mountains by 1955. DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -53- spent 4 days surveying the vicinity of the May 1979 observa- Ligon, J.S. 1927. Wildlife of New Mexico: its conservation and tion (Sandoval, 1979a). No bighorn were located. In April 1980, management. New Mexico Dept. Game & Fish, Santa Fe, 3 Department biologists spent 30 hours as observers in 136 pp. helicopter flights to attempt to locate sheep. These surveys Miller, G.S., and R. Kellog. 1955. North American recent mam- did not result in any observations of bighorn sheep (Sandoval mals. Bull. No. 205, U.S. National Mus., Washington, D.C., 1980b). p. 822. Two theories have been advanced on the source of the sheep Newell, N.O. 1953. The Permian Reef Complex on the Guada- observed in 1979. The first is that these sheep represent a rem- lupe Mountain Region, Texas and New Mexico. W.H. Free- nant population that have not been observed until recent time man and Co., San Francisco, CA, 236 pp. (Sandoval, 1980b). This theory is unlikely in light of the fact Sandoval, A. 1979a. Guadalupe Mountains desert bighorn that ranchers, backpackers, and hunters use the area exten- sheep survey. On file, New Mexico Dept. Game & Fish, sively. It seems likely that these users would have observed Santa Fe, 5 pp. any bighorns inhabiting the area. The second possibility is that the bighorns are migrants from a 1973 release of desert . 1979b. Preliminary survey report: evaluation of bighorn sheep in the Sierra Diablo Mountains of Texas historic desert bighorn sheep ranges. New Mexico Dept. (Winkler, 1980). The Texas Parks and Wildlife Department has Game & Fish, Santa Fe, 228 pp. been unable to account for some of their 1973 release and they . 1980a. Unconfirmed sighting of desert bighorn could have migrated to the Guadalupe Mountains by way of sheep in the Guadalupe Mountains. On file, New Mexico the Delaware Mountains (Winkler, 1980). Dept. Game & Fish, Santa Fe, 3 pp. Sandoval (1979b) issued a report on the evaluation of historic . 1980b. Guadalupe Mountains helicopter survey desert bighorn sheep ranges in New Mexico. He determined results. On file, New Mexico Dept. Game & Fish, Santa that there were 16,058 ha (39,680 ac.) in the Guadalupe Moun- Fe, 19 pp. tains that could be classified as good bighorn habitat. Another 10,360 ha. (25,600 ac.) was classified as marginal habitat. San- Schaafsma, Polly. 1972. Rock art in New Mexico. University doval also stated that the major factor limiting the Guadalupe of New Mexico Press, Albuquerque, 209 pp. Mountains as a potential release site for desert bighorn is the Simmons, L.W. 1946. Letter to Elliott S. Barker. New Mexico apparent wide distribution of aoudads. Dept. Game & Fish files, Santa Fe, 1 pp. The future of the desert bighorn sheep in the Guadalupes is Simpson, C.D., and T.J. Leftwich. 1976. Desert bighorn sheep: spelled out in New,Mexico's comprehensive wildlife plan, com- a feasibility study on their reintroduction to the Guada- pleted in 1980. This plan calls for the, bighorn to receive lupe Mountains. Report from NPS files, Carlsbad, New management priority in the area. The 2 most important steps Mexico, 26 pp. in the plan call for reduction of the aoudad population by sport Snow, R., and E. Zirnmerman. 1939. Bighorn sheep report. hunting and direct removal, and for the eventual reintroduction Carbon on file, New Mexico Dept. Game & Fish, Santa Fe, of desert bighorn sheep into their historical habitat in the typed and incomplete. Guadalupe Mountains. Winkler, C.K. 1980. Letter to Bruce L. Morrison, New Mexico Dept. Game & Fish files, Roswell, 2 pp. LITERATURE CITED Bailey, V. 1905. Biological survey of Texas. USDA Bur. Biol. Surv. North American Fauna 25, 222 pp. . 1928. Animal life of the Carlsbad Caverns. Mono. Amer. Soc. Mamm., No. 3, Baltimore, MD, 185 pp. . 1931. Mammals of New Mexico. USDA Bur. Biol. Surv. North American Fauna 53, 412 pp. Barker, E.S. 1938. Bighorn survey report. Carbon on file, N.M. Dept. Game & Fish, Santa Fe, 4 pp. Barnett, J. n.d. Guadalupe Mountains National Park. Carls- bad Caverns Natural History Assn., Carlsbad, NM, 32 pp. Bowden, J.J. 1975. Surveying the Texas and Pacific land grant west of the Pecos River. Univ. of Texas, El Paso, Southwestern Studies Mono. No. 46, 27 pp. Buechner, H.K. 1960. The bighorn sheep in the United States, its past, present, and future. Wildl. Soc. Mono. No. 4, Washington, D.C., 174 pp. Gross, J.E. 1960. History and present and future status of the desert bighorn sheep (Ovis canadensis mexicana) in the Guadalupe Mountains of southeastern New Mexico and northwestern Texas. DBC Trans., pp. 66-71. Harris, A.H., and P. Mundell. 1974. Size reduction in bighorn sheep (Ovis canadensis) at the close of the Pleisto- cene. J. of Mamm. 55(3):678-680. Hollon, W. 1955. Beyond the cross timbers; the travels of Ran- dolph B. Marcy. Univ. of Oklahoma Press, Oklahoma City, OK, 270 pp. Katz, P.R. 1978. An inventory and assessment of archaeological sites in the high country of Guadalupe Mountains Na- tional Park, Texas, Archaeol. Surv. Rept. #36, Center for Archaeol. Research, Unw. of Texas, San Antonio, 91 pp. -54- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS ject was generated by the Department in 1973 with written ap- RESULTS OF A proval for the transplant provided by the BLM in 1974 (Rowland, 1974). Upon completion of other reintroductions in DIRECT RELEASE the state, the Virgin Range became the number one priority for a desert sheep transplant after 1977 (Tsukamoto, 1977). A DESERT BIGHORN SHEEP release site description was then prepared by the Department that included a complete history of land use and past populations in the area (McQuivey, 1978). An agreement to capture TRANSPLANT IN THE the needed animals from the River Mountain population was secured from the NPS during the annual interagency meetrng VIRGIN MOUNTAINS that was held during January of 1979. OF NEVADA After completing the successful transplant of 21 bighorn into the Virgin Mountain Range in June of 1979, and monitoring the behavior and movement patterns of the marked sheep during the following three months, it was recommended that an additional 20 bighorn be transplanted to the same general area the following year. The primary reason for the recommendation Robert P. McQuivey was because of equipment failure that resulted in four of the Nevada Dept. of Wildlife eight radio-collars ceasing to function by September Of 1979. Las Vegas, NV 89158 Within the first six months of the project, seven of the eight collars had quit working. The monitoring of radio-collared Dave Pulliam animals was an important facet of the project which most of Bureau of Land Management the objectives listed in the cooperative study plan depended Las Vegas, NV 89108 upon(McQuivey and Pulliam, 1979a). The recommendations were favorably received by all cooperating agencies which resulted in the necessary agreements to trap and transplant Abstract. A total of 42 bighorn sheep were wild-trapped from an additional 20 sheep from the River Mountains during the the River Mountain herd of Clark County, Nevada between summer months of 1980. June of 1979 and August of 1980 and subsequently released at three different locations on the Virgin Mountain Range of METHODS Clark Co. Some 755 sightings andlor radio telemetry locations A general description of the methods used to capture desert are now available by which to describe the behavior and move- bighorn during 1979 was presented in the first semi-annual ment patterns of the introduced herd. Preliminary results show progress report (McQuivey and Pulliam, 1979b). In brief, a total that desert sheep introduced into unfamiliar environments are of 21 animals was captured at the Southern Nevada Water Pro- highly exploratory. Successful reproduction and survival of ject on the River Mountains during June using the drop gate lambs were documented during the first year of the project panel trap. All of the animals were visibly marked (eight with with a minimum of three yearlings in the herd at the oresent radio-collars) and released directly into the wild at Cabin time. This is the fourth in a series of similar semi-annual Spring on the Virgin Mountain Range. Follow-up efforts during status and trend reports relative to the Virgin Mountain rein- the first year included scheduled fixed-wing flights on a week- troduction project. ly basis between June and September with semi-monthly flights thereafter until December, when flights were cancelled INTRODUCTION because of transmitter failure. Intensive ground follow-up efforts were accomplished by a graduate researcher, David C. Desert bighorn sheep (Ovis canadensis nelsoni) were recently Jones, between June and October with field work after reintroduced into the Virgin Mountain Range of Clark County, December also being minimal. Nevada in an attempt to increase the distribution and abundance of the species in the state. The bighorn were The procedures used to capture sheep during the summer wild-trapped from the River Mountain population through months of 1980 deserve special attention since a newly con- cooperative agreement with the National Park Service INPS] structed drop net trap that was designed by Ramsey (1968) and (Lake Mead National Recreation Area) and released on public modified by Schmidt and Rutherford (1978) proved to be very domain administered by the Las Vegas District of the Bureau successful. The technique utilizes 70 by 70 feet of netting corn- of Land Management [BLM]. The follow-up study is a pletely suspended over bait of fermented apple pulp. The ma- cooperative venture between the Nevada Department of jor advantage of the drop net trap over methods previously Wildlife [NDOW] and the BLM with the responsibilities of each used in Nevada is that bighorn are lured under the netting agency described in a cooperative agreement. because of their desire for the bait rather than being forced in- to a trap because of their need for free water. A second advan- This document includes a presentation and analysis of all data tage is that bighorn are immediately restrained by the fallen collected through March 31, 1981. Current plans include the net, whereas they must be physically wrestled to the ground continuation of bimonthly fixed-wing flights through at least with the previously used drop gate panel trap. The proven ad- September of 1981 as a means of documenting the movement diction of Nelson's bighorn sheep to the apple pulp should patterns of radio-collared animals. A full-time enployee is also also allow future trapping in areas where previously used programmed for the project during the summer months of 1981 methods have been unsuccessful or impossible (such as along as a means of gathering intensive information relative to the the Colorado River). population dynamics of the herd. Follow-up efforts should continue through the summer season of 1982 after which a The vicinity of the NPS horse corral on the River Mountains final completion report will be prepared. was selected as the 1980 trapping site since it was a natural concentration area for bighorn and because previous at- BACKGROUND tempts to capture sheep from the area using the drop gate The Virgin Mountain area was first identified by the NDOW as panel trap were unsuccessful. Apple pulp was distributed ad- a potential reintroduction site for bighorn in 1951 with early at- jacent to the water source beginning on May 23 as a means of tempts fo capture the needed animals from the Sheep Moun- familiarizing the animals with the substance. Bighorn showed tain Range being unsuccessful. Renewed interest for the pro- no interest in the bait f~,rne nrst week even though some in- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -55- dividuals visited the site daily. The bighorn began utilizing the Several of these 1979 animals have intermixed freely with apple pulp by the eighth day and were consuming large quan- those released during 1980 since major movement patterns tities within 10 days. The bait station was then moved to during both years were directred toward areas of common use. relatively flat terrain some 30 yards from the water source. The The data also continue to show the lack of specific group sheep continued to consume largequantities of the pulp at the cohesion among most animals. new location almost immediately. Data collected during the summer months of 1980 show that a The trap was erected over the bait station on June 23 with ap- minimum of 4 lambs were born on the Virgin Mountain Range proximately 40 bighorn watching the operation from nearby during the first year of the project. These data are particularly cliffs. Within 45 minutes of the project completion, there were significant in view of the composition of bighorn released the 23 total sheep directly under the suspended net consuming first year which included only yearling rams in addition to 9 the bait. The bighorn appeared to be much less hesitant about adult ewes. The information indicates that young rams are ful- walking under the net than had been the case for the same ly capable of accomplishing the necessary breeding in the animals entering the enclosed drop gate panel trap. absence of older aged rams. Although recent field work has A successful drop on June 28 resulted in the capture of nine been limited during the past several months, random observa- bighorn sheep of which eight were marked and loaded into the tions indicate that at least 3 completely unmarked yearlings Department's three-ton transport truck. One female lamb was are currently present in the population. lost during the operation due to trapping stress or capture Home range and movement patterns are as variable among myopathy. The following morning a group of nine sheep ap- animals released in 1980 as they were for the sheep released proached the trap at a full run with eight of the animals moving during 1979. Some individuals show a high degree of ex- directly under the net without hesitation. This group was cap- ploratory behavior, whereas others are much more sedentary. tured, marked, loaded into the truck, and transported with the Virtually all major movements of animals from both years have eight sheep from the previous day to the Virgin 'Moutnains been toward the south, the general direction of the original Range. All 16 bighorn were released at Dud Spring in excellent trap site. condition. Recorded data for the single animal that continues to carry a Attempts to capture the remaining animals needed to com- functional radio-collar from 1979 and totaling some 63 loca- plete the Virgin Mountain project were delayed until August 12 tions to date is of particular interest. This adult ewe was because of locally heavy rains in the vicinity of the trap site released at Cabin Spring during June of 1979 and immediately during the month of July. It is significant that even though the began to explore most of the suitable habitat in the vicinity of herd was considered "hooked" on the bait early in'the sum- the release site. Within the first month she made one sashay mer, water that collected in natural catchments during July of about 13 miles in addition to several trips of shorter dura- resulted in a major migration of the herd to higher elevations. tion and length. By late July this individual appeared to have The 5 animals needed to complete the project were finally cap- established residency in the vicinity of Bitter Ridge, an area tured, marked, and transported on August 12 and released at that was also occupied by other transplanted sheep. She was Government Spring in good condition (McQuivey, 1980~). consistently found in this area for the next six month period. Follow-up efforts during 1980 paralleled those documented for In January 1980 the ewe again began to exhibit extremes in ex- 1979 with weekly fixed-wing flights between June and ploratory behavior that consisted of several trips of short dura- September and bimonthly surveys thereafter through the pre- tion in addition to a long move of 16 miles during the month of sent time. Intensive ground Surveys were conducted by a temp- March. She then returned to the vicinity of Bitter Ridge and re- orary full-time employee (Sue Inkel) between June and mained for 12 months. During March of 1981 the ewe migrated November, with field work reduced since December. One inten- to the same general area that she had visited the year before in sive helicopter survey was conducted during March of 1981 in addition to moving another8 miles further south (24 miles from an effort to document spring lamb production (Pulliam et al, Bitter Ridge). She remained at the distant location for approx- 1980). imately 3 weeks after which she returned to Bitter Ridge where RESULTS she has remained. Based on a single observation in addition to several radio locations, she appeared to have made the long A total of 755 observations andlor radio telemetry locations trek alone. have been recorded for 42 marked animals on the Virgin Moun- tains ranging from one sighting for an uncollared yearling ram Observations and radio locations for two ewes released during to 63 locations for a radio-collared ewe that was released dur- 1980 (105 total locations) show opposite movement patterns ing 1979. Because of radio failures within 6 months for 7 of the as these individuals have remained in the vicinity of 2 perma- 8 bighorn in 1979, a majority of the recent data pertains to nent water sources, one at the release site and the other less those animals released during 1980 (64% of all locations). The than 5 miles distant. The ewes are often found together and data continue to show the importance of radio collars in neither moves any great distance from week to week. locating bighorn, since an average of 42 locations are available for each of the 8 radio-collared sheep; whereas an RECOMMENDATIONS average of 11 locations are available for the remaining 13 un- Field work by a temporary full-time employee during the sum- collared animals. mer months of 1981 will provide 3 years of consecutive data The documented survival of all 42 transplanted animals for a during this Tmportani time of the year. Bimonthly fixed wing minimum of 3 weeks after their release is important in showing flights are also anticipated through the summer season of that capture myopathy was not a significant mortality factor 1982 or until most of the radio-collars become nonfunctional. for the Virgin Mountain project. The actual observation of 40 Occasional helicopter inventories will be scheduled as needed individuals for at least 3 months after their respective releases in order to gather information that cannot otherwise be col- also suggests that predation was not a significant mortality lected. Seasonal fecal samples will also be collected begin- factor. To date there have been only 3 confirmed mortalities in ning this winter as a means of documenting forage preference the herd: 2 radio-collared ewes from the 1980 release and a for the introduced herd. very young lamb that was born in the area during the summer A complete analysis of all data collected will be conducted months of 1980. next year with the aid of computer programming through the Continued follow-up information on a regular basis is available Denver Service Center. The final report for this project is for only 11 of the original 21 sheep released during 1979. scheduled to be completed by the end of 1982. -56- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS LITERATURE CITED McQuivey, R.P. 1978. Virgin Mountain bighorn sheep reintro- A SUMMARY OF duction proposal - release site description. Nev. Dept. of Wildl. 11 pp. CAPTURE EFFORTS and D. Pulliam. 1979a. Study plan for the Virgin IN ARIZONA SINCE 1977 Mountain reintroduction project. Typed manuscript. 4 pp. . 1979b. Desert bighorn sheep introduction and follow-up on the Virgin Mountains of Clark County, James C. deVos Nevada. First cooperative quarterly report. 9 pp. Arizona Game & Fish Dept. . 1980~.Preliminary results of a wild-release Phoenix, AZ desert bighorn sheep transplant in Nevada. Desert Bighorn Transactions, pp. 57-61. Richard Remington Arizona Game & Fish Dept. Pulliam, D., S. Inkel, and R.P. McQuivey. 1980. Desert bighorn Yuma, AZ sheep introduction and follow-up on the Virgin Mountains of Clark County Nevada. Third cooperative progress report. 11 pp. Abstract. Arizona Game and Fish Department has initiated Ramsey, C.W. 1968. A drop net deer trap. J. of Wildl. Mgmt. an aggressive transplant program which required developing a Vol. 32, NO. 1, pp. 187-190. cost effective, low mortality capture technique. A method us- Rowland, E.I. 1974. Letter of approval from ELM to NDOW for ing Etorphine (M-99) and a tranquilizer injected by means of bighorn transplant sites. 2 pp. Palmer Cap-Chur equipment fired from a helicopter was Schmidt, R.L. and W.H. Rutherford. 1978. Colorado bighorn developed in 1971. This method was modified into the techni- sheep trapping techniques. Wildl. Soc. Bull., Vol. 6, que described within. No. 3, pp. 159-163. This technique was used to capture 165 desert bighorn in Tsukamoto, G.K. 1977. Desert bighorn sheep potential trans- Arizona since 1977. Five of these animals have died as a direct plant sites, Nev. Dept. of Wildl. 3 pp. result of capture operations. Necropsies showed the cause of death in most cases to be hyperthermia. No animals have shown symptoms of capture myopathy.

In Arizona, the need to develop a suitable method to capture desert bighorn sheep (Ovis canadensis) became of importance in 1955, when a multi-agency cooperative agreement, requiring the capture of 50 bighorns, was consummated. Under this agreement, 25 bighorns were to be shipped to the Black Gap area of Texas and 25 were to be released in historic habitat in Arizona. First attempts to capture sheep utilized various trapping methods around waterholes during summer months. The most successfuI method utilized an &foot high net corral trap with a drop gate around permanent wateiholes in the Kofa and New Water Mountains. Animals were trapped, physically restrained, tranquilized, then transported. Drawbacks to this method were high cost and high bighorn mortality. It was the unac- ceptable mortality rate that led to the suspension of trapping efforts. Research was initiated to develop a practical method to immobilize free roaming bighorns (Russo 1968). The first attempts involved darting animals from the ground as they approached waterholes. As a result of these investigations it was determined that Etorphine (M-99) injected using Cap-Chur equipment provided sufficient immobilization. Nine sheep were captured by this method. This tect-nique, though successful, was not without problems. Animals had to be captured at waterholes during the summer when demand for water was greatest. Darting from the ground allowed animals to flee, resulting in prolonged chases on foot. Other researchers were also attempting to develop capture techniques for wild sheep. Logsdon (1967) attempted to administer an oral tranquilizer but the lack of a suitable drug limited the effectiveness of this test. Logsdon also attempted to capture free ranging desert bighorns using Paxarrn and Cap-Chur equipment. Two animals were injected with Sernylan and one with Diazepam. Only the animal which had been injected with 1.04 mgllb of Sernylan could be captured. In 1971, biologists from Arizona utilized M-99 in combination with a tranquilizer to capture3 ewes in the Plomosa Mountains (Weaver 1973). This was the first capture of bighorns using a DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -57- helicopter and drug combinations. In 1972, personnel from After a sheep is stopped, the approach should be from above New Mexico utilized these methods to capture 11 bighorns the animal and should be accomplished with the helicopter (Montoya 1973). In the 2 capture efforts drug dosage ranged slowly lowering into shooting range. For best results shots from 2.0 to 2.5 mg M-99 and 2.0 to 20.0 mg Azaperone. over 30-35 feet should be avoided. Care is taken to avoid shots Arizona's bighorn captures were limited from 1972 until 1977. outside the edge of the rotors as trajectory will be influenced In 1977, a study to document impacts of powerline construc- by air turbulence. Altered trajectory could result in a shot in tion in sheep habitat was initiated. To fulfill the requirements the flank areas which could damage internal organs or cause of this program 20 sheep were captured. This was the begin- peritonitis. Shots are made into the fleshy area of the rump. ning of an active capture and transplant program. The edge of the white rump patch makes a good point of aim. A secondary area for injection is the front shoulder; however, METHODS UTILIZED SINCE 1977 risk of a bone strike is much greater. Shots at moving desert Guns. The Palmer long range projector is the only rifle that bighorns are possible but risk of an errant shot is increased. has been used in Arizona's capture work. The use'of one full Post Darting Procedures: After an animal is darted, the and one empty C02 charge has proven effective. To avoid helicopter moves away from the animal as far as possible, reduced gas pressure in extremely cold weather, the gun can while still maintaining visual contact. This limits the stress on be wrapped in a blanket or held near a heater vent. the drugged bighorn. Avoid chasing an animal after it has been Darts: The drug dosage that we have used to immobilize darted. Due to depressed respiration rates, as a result of the bighorns require the use of 3 cc darts. In some cases, when drugs, the possibility of capture myopathy increases as capturing young rams (2-5 years old) we have used an addi- movements increase. Signs of ataxia should be evident in less tional 2 cc dart to administer drugs. It appeared that this age than 5 minutes. If little or no evidence of ataxia occurs within ram required a larger dose of M-99 to effect complete im- 8-10 minutes the animal should be re-darted. mobilization. Tail pieces on darts are fluffed to enhance a Post Immobilization Procedure: After an animal is immobiliz- stable dart flight. The first needles used were 3/4 inch collared ed it can easily be approached on foot. Care is taken to ap- needles, but when using these it was common to observe a proach quietly and from above the animal. Bighorns are held spray of drugs as the dart bounced out of the animal. To insure by the horns since generally the animal is subdued when a that each bighorn obtained a full drug injection, later captures horn is held. The sheep should be blindfolded immediately utilized a barbed dart. Although concern was expressed that after being restrained. This reduces the stress caused by the barbed dart would cause undue tissue damage, post mor- handling. The next step is a cursory inspection of the physical turn examination of injection wounds indicated little or no dif- condition of the immobilized sheep. Respiration rates, heart ference in tissue damage between the 2 needle types. beat, body temperature, and gum color are checked. If the Drugs and Dosages: A number of different drugs and com- animal is in good condition it can be transported. Animals that binations of drugs have been used. They are as follows: are severely stressed or have high body temperatures should 1. 1977 - 2.5 to 2.7 mg Etorphine with 20 mg be stabilized prior to transporting. Temperatures can be Azaperone. lowered by holding ice packs along the base of the neck or by 2. 1978 - 2.5 to 2.7 mg Etorphine with 15-20 mg wetting the animal with water. For severely stressed animals Azaperone. an intravenous injection of Ringer's solution is administered in conjunction with sodium bicarbonate. This will replace lost 3. 1979a- 2.5 to 3.0 mg Etorphine with 20-25 mg plasma volume and raise blood pH to limit the danger of Azaperone. acidosis. In severe cases, oxygen can be administered with the 4. 1980a- 2.5 to 2.7 mg Etorphine with 20-30 mg use of a nose cone. In most case it is best to transport as soon Azaperone. as possible. 1980b- 2.5 mg Etorphine with 20 mg Rompun. Transport: Transportation has been best accomplished with 1980c- 3.5 mg Etorphine with 20 mg Azaperone. the use of a cargo net. Mesh sizes that have been used in 1980d- 2.5 mg Etorphine with 20 dig Azaperone and Arizona ranged from 6 to 10 inches. Each corner of the net has 150 USP units Wydase (Hyaluronidase). a steel ring which is connected to the tow line on the All combinations have been successful in immobilizing free helicopter. Once an animal is down, the net can be dropped roaming bighorn. Benefits and drawbacks of each combina- from the helicopter which eliminates carrying a heavy net in tion will be discussed later. Azaperone is a neuroleptic of the rugged terrain. To load an animal in the net, the net is laid flat butyrophenone series, and has not been approved for.general on the ground, with the animal laid on its brisket in the center. veterinary use in the USA. Azaperone (trade name Stresnil) was Animals are not placed on their side, because as it is lifted the provided by Pitman-Moore, Inc. of New Jersey. sheep may roll onto its back and possibly inhale rumen contents. After the animal is in the net, the net is secured to the Helicopter: During the capture of bighorn 3 different types of tow line and the pilot is signaled to slowly raise the animal helicopters were used: a Bell B-1, a Hughes 500, and a Bell Jet from the ground. As the animal is raised, all legs are checked Ranger. All helicopters were successful in pursuing bighorns to insure the sheep will be transported in a natural position. and effecting capture. Jet helicopters are preterred; these are We also check that the horns are not hooked to any part of the powerful enough to carry 2 passengers and transport captured net. If the animal is riding naturally, the pilot is signaled to animals. The Hughes aircraft may be more suitable for right transport it to camp. handed gunners since shooting is done from the left side of Care at Camp: As soon as the sheep arrive in camp, the ship. The opposite is true for the Jet Ranger. temperature, heart rate, and respiration are monitored again. Approach and Darting: Approach to an animal is a critical Body temperatures in excess of 105°F are potentially very aspect of successful captures. We have found it best not to dangerous and are lowered as soon as possible. Immersion in pursue sheep from below or behind, because they tend to run a dip tank or dousing with water has proven effective. After an rather than stop and hide. To make an animal stop and to animal's condition has been stabilized it is checked for in- facilitate darting, an approach from above and ahead to cut off juries. Dart wounds and dermal abrasions are treated with an escape has proven effective. To reduce chase time, areas are antibiotic salve or spray. All animals are injected with a long selected where sheep can "hide" in a cave, next to a rock bluff, lasting, broad spectrum antibiotic. While the animal is still im- or behind a large tree. Flats or areas where hiding spots are mobilized, biological samples, i.e. blood samples, ear scrap- absent are avoided because sheep tend to run for longer ing~and fecal pellets can be collected. Animals can be ear- periods and the danger of capture myopathy is increased. tagged and radio-collared prior to reversal. Reversal is ac- -58- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS complished by intravenous administration of M50-50 at a of M50-50. The mean reversal time was 3.8 minutes for rams, dosage of 2 mgll mg M-99. Animals are placed in a crate or 4.1 minutes for ewes. trailer prior to reversal. The only year where a large difference was found was in 1977, In Arizona, a horse trailer with all openings covered by when the mean time was 7.1 minutes. Mean reversal time for pl~woodhas proven successful in transporting sheep. For a 1978, 1979, and 1980 was 3.5 minutes, 2.5 minutes, and 4.3 short term, food and water are not necessary; however, if minutes respectively. The overall mean for all 86 cases ex- animals are held over 24 hours, food and water is provided. amined was 4.0 minutes. Animals should not be overcrowded in the transport facility. Thirteen or 14 sheep is the maximum held in a 4-horse trailer. Total Time: Total time is the sum of all times recorded during captures. This parameter is a predictor of capture success. During capture, the trailer is parked in the shade, away from Dalton et al. (1978) reported that in Utah when total time ex- camp to avoid unnecessary stress. ceeded 52 to 74 minutes a mortality rate of 95% could be ex- Data Collection: A form was designed to standardize data pected. collection. This enhanced data collection and helped avoid in- Sample size for total time in 1977 was small and data were ex- advertent data deletions. cluded from analysis. Mean total time for 1978 was 57.8 RESULTS minutes. This was noticably different than 1979 and 1980, Since 1977, 165 bighorn have been captured in Arizona. All when total time was 38.0 minutes and 34.2 minutes respective- captures entailed the use of M-99, in conjunction with a tran- ly. There was little difference between rams and ewes. For all quilizer. Only 5 sheep have died as a direct result of capture. cases examined, rams had a mean 38.0 minutes; ewes had a This is a capture success rate of 97%. Field necropsies show- mean value of 35.4 minutes. The overall mean when all data ed the cause of death, in most instances, was hyperthermia. were examined was 36.2 minutes. Times relative to the capture were recorded on most captures DISCUSSION as an aid in evaluating each capture. Parameters measured The capture technique used in Arizona has proven effective. were: chase time, reaction time, down or immobilization time, This technique is the product of trial over error. Experirnenta- reversal time, and total handling time. tion has been in 2 major categories: 1) drug dosages and com- Chase Time: Chase time was calculated as the time required bination; 2) delivery systems. to dart a sheep after initial observation. For sheep that had to The drug dosage that we found most effective in immobilizing be darted more than once, chase time was recorded from in- bighorn is 2.5 mg M-99 in conjunction with 20-25 mg itial observation until a dart was fired that caused ataxia. Azaperone. Smaller doses of M-99 failed to effect complete im- Mean chase time for ewes was 8.0 minutes for rams 11.5 mobilization. For prime aged (2-5 year olds) rams, 3.5 mg M-99 minutes, and for all sheep 9.2 minutes. is preferred for immobilization sufficient to reduce the possibility of hyperthermia as a result of increased energy ex- Chase time varied from 16.0 minutes in 1978 to 7.8 in 1979 and penditure while underdosed. was 8.3 in 1980. The long chase times recorded in 1978 are the result of many sheep having to be shot more than once, at- Azaperone has proven to be the best tranquilizer that we have tributable to the use of collared needles which appeared to be tested. Rompun with M-99 proved to be an unsatisfactory com- ineffective in achieving a total drug injection. In 1979 and 1980, bination. Animals which required 2 injections of 2.5 mg M-99 when barbed needles were used, fewer sheep had to be darted and 20 mg Rompun for immobilization were difficult to reverse, twice and chase times were reduced. necessitating considerable veterinarian attention. Reaction Time: Reaction time is a measure of drug dosage In 1979 one capture was effected with M-99 alone. This capture and delivery system effectiveness. For 115 captures the mean was very difficult as the sheep appeared to be able to "fight" value was 5.0 minutes. When reaction time was compared be- the effect of the drug and elude peopie trying to catch her. tween years, 1978 was notably different. In 1978, mean reac- Total handling time for this animal was the longest recorded tion 'time was 7.0 minutes. Times recorded for 1977, 1979, and (in excess of 90 minutes). 1980 were 3.7, 5.3, and 4.7 minutes respectively. This dif- In an effort to reduce reaction and down times 150 USP units ference may partially be explained in that the tranquilizer used of Wydase (Hyaluronidase) was added to 2.5 mg M-99 and 20 in 1978 had been stored for over a year, possibly losing some mg Azaperone. This drug was used in 3 captures but did not potency. Also, as identified earlier, the delivery system used in seem to decrease down times. This drug combination will be 1978 was not adequate. tested further. When reaction time for all aged ewes was analyzed the mean The change from a collared needle to a barbed needle reduced value was 4.7 minutes, for rams 5.6 minutes. Longer chase the down times considerably. The barb appears to hold the times and larger body size of rams probably account for this dart in the muscle long enough for total drug injection. In addi- difference. tion, most barbed needles can be recovered as the barb catches on the skin and must be removed after the animal is Down Time: Down time is the time required for an animal to immobilized. lay down after the first sign of ataxia is observed. In 1977 and LITERATURE CITED 1978 many animals never went down and were handled stand- Dalton, Larry B., Joy A. Roberson, and James W. Bates. 1978. ing up. This was probably a result of incomplete drug injection. Capture myopathy in desert bighorns-literature review This problem is reflected by the mean down time calculated in and treatment. DBC Trans. pp. 31-35. these years, 9.0 minutes in 1977 and 7.4 minutes in 1978. The Logsdon, H. Steven. 1967. Preliminary results of administering mean down time calculated in 1979 and 1980 was 5.8 minutes drugs to desert bighorn sheep for capture purposes. DBC and 3.7 minutes respectively. A continued reduction in down Trans. pp. 27-52. time was observed from 1977 to 1980. Montoya, Bill. 1973. Bighorn sheep capture techniques. DBC As with chase time and reaction time, down time is greater for Trans. pp. 155-163. rams than ewes (6.1 minutes vs. 5.3 minutes). The probable Russo, John R. 1968. Arizona bighorn management and re- causes are the same factors discussed under reaction time. search activities, 1967-68. DBC Trans. pp. 5-6. Reversal Time: Reversal time is calculated as the time re- Weaver, Robert K. 1973. Progress at Aravaipa, DBC Trans. quired for an animal to regain mobility after the administration pp. 117-122.

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -59- has been successful in completing 10 individual transplants 1 STATUS OF THE on 7 mountain ranges in the state without the use of enclosures; the stonewall Mountain project was the first. The STONEWALL MOUNTAIN initial success of these transplants lends credence to the sug- gestion that if suitable habitat is available, bighorn will survive DESERT BIGHORN SHEEP and reproduce without the protective measures of an enclosure. This project was partially funded by federal aid REINTRODUCTION funds secured through the Pittman-Robinson Act. PROJECT OF BACKGROUND CENTRAL NEVADA Stonewall Mountain was recognized by the NDOW as a high priority site for the reintroduction of bighorn in 1974. Coordina- tion efforts with the appropriate land managing agencies and major range users were completed during 1975 yielding a cooperative agreement with the National Park Service [NPS] to Robert P. McQuivey remove the needed bighorn from the River Mountain popula- Nevada Dept. of Wildlife tion of the Lake Mead National Recreation Area. Letters of ap- Las Vegas, NV 89158 proval for the project were also secured from the Bureau of Land Management [BLM] and the U.S. Air Force since part of the habitat is Public Domain and the remainder is located on Abstract. The reintroduction of desert bighorn sheep (Ovis the Nellis Air Force Bombing and Gunnery Range. canadensis nelsoni) into the Stonewall Mountain area of Nye A habitat evaluation conducted in 1975 indicated that approx- County, Nevada represents the first direct-release of this imately 16 square miles of continuous good habitat were subspecies in the state. Information gathered during the past available for bighorn on the north end of the range with addi- 6 years shows that natural reproduction has occurred in the tional marginal areas available in adjacent section of the wild and suggests that a viable and resident population of at mountain. Major limiting factors throughout most of the least 35 individuals has been established within a2 mile radius marginal habitat appeared to be the lack of adequate escape of the release sites. terrain and concerns relative to a feral horse population in the area. Based on average densities of bighorn in similar habitat INTRODUCTION types of Nevada, it was suspected that the Stonewall Range Philosophies relative to the techniques used for reintroducing could support a minimum resident population of 80-100 sheep. bighorn sheep of all species were closely reviewed and subsequently altered in Nevada during 1975. A major change in METHODS management direction resulted in the direct release of bighorn into new habitats rather than confining the animals inside Plans to capture 12 bighorn sheep at the Southern Nevada fenced enclosures. The decision to use direct releases was Water Project in the River Mountains for relocation to based on costlbenefi:~ in addition to a thorongh analysis of Stonewall Mountain were delayed in 1975 because of an ex- the success or failure of past projects throughout the isting population study in the area and because of inclement southwest. Since 1975 the Nevada Dept. of Wildlife [NDOW] weather late in the season. As a result only 8 sheep were cap-

Table. 1. Summary of the bighorn sheep observations on Stonewall Mountain resulting from helicopter inventories.

Survey Ram Ages Date Time Total Ewes Lambs Rams 1234567

Jan. 1975 No Bighorn Sheep Observed Feb. 1976 No Bighorn Sheep Observed July 1976 No Bighorn Sheep Observed Sept I976 No Bighorn Sheep Observed

Feb. 1978 Feb. 1979 Sept 1979 Sept 1980 Feb. 1981

TOTALS 16.0 Hr 113 75 20 18 7811-- 1

-60- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS 5'

'58

I57

4155

"54

1010000 FEET WEST)

T "5

4151000m N

37"301 00'

2558 1 NE ROAD CLASSIFICATION ,9Sd 2 3 4 MILES 4 Heavyduty - Light duty =- 12000 15000 18000 21000 FEET ----l- 3 4 5 KILOMETERS .--~ 4 1 I__! U. S. Route (7State Route 1 NEVADA 1

U QUADRANGLE LOCATION GOLDFIELD, NEV. N3730-W11700/15

1952

AMS 2559 II-SERIES V795

Figure 1. Distribution of bighorn sheep on Stonewall Mountain resulting from a direct release during 1975 and 1977.

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -61- tured using the drop gate panel trap on August 13, 1975 and 4 bighorn in addition to 113 sightings that were recorded dur- released in good condition the following day on the north side ing helicopter surveys over the past 4 years (Table 1). The data of the Stonewall Range. The composition of the group cap- are important in showing that the population has not only in- tured included 3 adult ewes, 3 lambs, and 2 rams that were ag- creased in numbers through natural reproduction since 1977, ed 1 and 2 years. Biological samples collected from all in- but also suggest that a significant amount of the seasonal use dividuals, consisting of fecal material, nasal swabs, ear scrap- is within a 2 mile radius of the original release sites. All of the ings, and blood, were analyzed by Dr. Robert Taylor of the aerial observations are presented in Figure 1 for comparative University of Nevada at Reno. The results showed the River purposes. Mountain herd to be free of any known contaglous disease but did indicate the presence of a gram negative rod shaped Aerial inventories on Stonewall Mountain document the suc- bacteria known as Pasturella. All the animals released were cessful production and survival of lambs in the wild during marked with aluminum strap ear tags in both ears for perma- each year since 1978. Lamb survival as measured during the nent identification. fall months appears to have ranged from a low of 10 lambs per 100 ewes (1980) to a high of 37 lambs per 100 ewes (1979). The most recent survey in the area (February 1981) suggests a record high year for production since 6 newborn lambs of less than 2 weeks of age were observed even though the peak period for lambing in the area is thought to be about March 1. These data show a minimum population of 35 individuals in the Stonewall herd at the present time which represents a 62.8% increase for the 22 animals released since 1975. Home range patterns for individuals in the introduced herd are limited since no bighorn were visibly marked during 1975 and only 1 adult ewe was radio-collared in 1977. Four observations of the marked ewe, however, continue to show that bighorn are highly exploratory when placed into unfamiliar environments. She was first observed by a Department biologist on September 19, 1977 (41 days after the release) approximately 18 airline miles northwest of the release site and in the company of two other adult ewes and a lamb. The location was within the city limits of Goldfield, Nevada and represented the traversing of extensive and fairly flat valley terrain. Residents from Goldfield reported observing the same group in the area for 4 days. This marked animal was not observed during the next 17 months but was finally sighted again on Stonewall Mountain February 9, 1979 during a helicopter inventory. She was located with 8 other unmarked bighorn some 2 miles southeast of the release site. The next sighting was September 19,1979 when she was observed with 18 sheep approximately 11/2 miles east of the release site. The last sighting of this ewe was on September 25,1980 when she was observed with 2 bighorn within 500 yards of the release site. These sightings represent a minimum walking distance of about 43 miles during the past 3 year period. Distribution patterns as shown in Figure 1 show that a majority of the bighorn use on Stonewall Mountain during the past 4 years has been within a 2 mile radius of the 2 release sites. The observation of lambs less than 2 weeks old is also important in showing that the introduced herd has utilized the vicinity of the release site for lambing. Those animals born on Stonewall Mountain since 1977 should be well imprinted and familiar Fourteen additional bighorn were captured at the same loca- with the habitat which may well increase the probability of the tion using similar methods on August 9, 1977 and released the herd becoming firmly established in the desired area. same day at Stonewall Spring, an area located approximately 2 miles from the 1975 release site. All of these sheep were marked with aluminum strap ear tags; one was fitted with a RECOMMENDATIONS radio-collar secured from Telonics, Inc., Mesa, AZ. No The Stonewall transplant project represents a good example biological samples were collected from the 1977 sheep since of a direct release bighorn sheep reintroduction without the past information had shown the population to be relatively aid of an enclosure that shows much promise of initial suc- disease-free. One of the animals relocated to Stonewall was a cess. Because of the favorable results from this project and 2 year old ewe that was marked on the River Mountains as a other similar reintroductions in the state, it is recommended lamb in 1975. Considerable home range information (40 that direct releases continue to be used in Nevada for future sightings) is available for this animal during its 2 year transplant projects. The initial release of 20 individuals with a residence on the River Mountain Range. ratio of 1 ram to 5 ewes appears to be sufficient for establishing a base population. It is also suggested that one RESULTS intensive helicopter survey per year, preferably conducted dur- The following discussion pertaining to results of the Stonewall ing the fallmonths, is adequate to document the annual incre- Mountain project are based on a single random observation of ment to the herd and resultant success of the project. -62- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS mountain lion predation has been observed on the Black Gap during the past year, perhaps due to the low mule deer and STATUS OF DESERT bighorn population on the Area. BIGHORN SHEEP At the Sierra Diablo Wildlife Management Area the free- ranging bighorns are seldom seen. A mule back census in the IN TEXAS summer of 1980 produced sightings of 2 rams and 1 ewe, and 8 sheep were seen near the headquarters later in the year. Department personnel feel there may be as many as 30 bighorns in 2 bands. There is a possibility that some of the bighorns released in the Sierra Diablos in 1973 have emigrated Charles K. Winkler to the Guadalupe Mountains of New Mexico and, in fact, may Texas Parks &Wildlife Dept. be ranging back and forth between the 2 ranges-a distance of Austin. TX 78744 approximately 70 miles. Following an unsuccessful attempt by the New Mexico Dept. of Game and Fish to confirm sightings of bighorns in the Guadalupes in 1979, 5 bighorns from the Abstract. During the past year, desert bighorn sheep restora- 1973 release were observed in Victorio Canyon. This was the tion activities in Texas have been minimal due to lack of fund- first observation of these sheep in 2 years. ing by the state legislature. A total of 56 desert bighorn Four ewes in the small brood pen on the Sierra Diablo Wildlife sheep is estimated to occur in the state. Free ranging popula. Management Area were captured in January 1981 and tions exist on the Black Gap and Sierra Diablo Wildlife transported to the Kerr Wildlife Management Area near Hunt. Management Areas. Captive desert bighorn sheep occur on The purpose of this transfer was to vacate the Sierra Diablo the Black Gap Wildlife Management Area, the Chilicote Ranch, pen in an effort to disinfect the pen of soremouth (contagious and Glaze Veterinary Clinic. Highlights of a status report ecthyma) virus. One ewe died of capture myopathy shortly documenting the history of the state's desert bighorn sheep after capture. Another died shortly after arrival at the Kerr restoration program are presented. Area. Cause of death was attributed to enterotoxemia. Both of the remaining ewes were captured, found to be suffering from Since September 1980, Texas has not officially had a desert enterotoxemia, and transferred to the Glaze Veterinary Clinic bighorn sheep (Ovis canadensis mexicana) program. This in Kerrville for treatment. They are presently doing well. situation resulted from action by the previous session of the Four other desert bighorns are at the Glaze Veterinary Clinic-a State Legislature, which reduced the Department's requested ram and 3 ewes. The oldest ewe of this group has never lac- appropriation for the bighorn program by 50% in the 1980 fis- tated and she, her yearling ram, and an ewe lamb were cal year and eliminated funding for the program in the current transferred from the enclosure at the Sierra Diablo Area to the fiscal year. The bighorn program was not the only victim- Glaze Veterinary Clinic in 1979. funding reductions were also mandated for white-tailed' deer Texas' fourth group of desert bighorn sheep is located in a 600-acre brood pasture on the Chilicote Ranch in Presidio County. During the past year, the status of this group of bighorns has been monitored by ranch personnel, who have informed the Department of lamb production, mortality, and general welfare of the sheep. At the present time there are 13 bighorns at this facility. Based on the above information, a statewide population of 56 desert bighorn sheep is estimated. In early 1980, with termination of state funding of the desert bighorn program a stark reality, the Department prepared a status report of the bighorn sheep program, which included a history of the program, the successes and failures, the present situation, the potential for the species' restoration, and recommended courses of action. The primary purpose of this document was to promote the formation of a privately-endowed foundation to ensure continuation of desert bighorn sheep restoration activities.

(Odocoileus virginiana), collared peccary (Dicotyles taiacu), Highlights of this report are: and aoudad sheep (Ammotragus lewia), although not to the extent of the bighorn program. At this time the outlook is 1. There are only 4 areas in Texas that have a potential favorable for restoration of funding for the program in the next for supporting bighorn sheep at the present time--the biennium (1981-83). Black Gap Wildlife Management Area, the Sierra Diablos, the Sierra Vieja, and the Eagle Mountains. All Despite the lack of funding, Texas' desert bighorn restoration but the latter area presently contain bighorns. program has continued, although activities of the Department 2. These areas could potentially support approximately and its personnel have been held to a minimum. 1,000 bighorns and an annual harvest of 23 niature Distribution and population estimates of desert bighorn sheep rams. in Texas are as follows: 3. Security of the Black Gap brood pasture from moun- On the Black Gap Wildlife Management, 1 adult ram remains in tain lion predation is prerequisite to the reintroduction the 427-acre brood pasture. Additionally, there are approx- of broodstock to the facility. imately 6 free-ranging sheep on the Area or in the immediate 4. Acquisition of additional broodstock is desirable if vicinity. This estimate is based on direct sightings and obser- the brood pasture on the Black Gap Area becomes vations of sign by Parks and Wildlife Dept. personnel, visitors usable andlor if a brood facility can be constructed in to the Area, adjacent ranchers, and others. No evidence of the Eagle Mountains.

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -63- Game and Fish propagation facility at Red Rock, New Mexico, MOVEMENTS AND for about 1 year, and transferred back to the San Andres Moun- tains on 8 January 1981. The 12 sheep transferred from Red MORTALITIES OF Rock were released by New Mexico Department of Game and Fish personnel as one herd at the base of the southeast por- DESERT BIGHORN SHEEP tion of Bennett Mountain. Movements. Figure 2 shows the dispersal patterns of the 12 IN THE SAN ANDRES re-introduced sheep. Comparisons of the areas where sheep were originally removed during salvage operations with disper- MOUNTAINS, sal patterns shows that these sheep tended to seek out former home ranges even after 1 year in confinement. A ram lamb NEW MEXICO born at Red Rock was the only sheep unfamiliar with the San Andres range. It initially crossed to the mountain complex south of the release site and then returned to the area just above the release site. The average distance between the extremes of home range was 7 km and 15 km for ewes and rams, Richard Munoz respectively. During March 1981 several sightings of sheep Las Cruces. New Mexico were made at unusually low elevations and probably were due to sheep seeking out newly emergent vegetation.

Sandoval (1979) discussed 5 relatively distinct herds on the southern San Andres range prior to the 1979 population decline. The 5 areas covered by the herds included Black Abstract. During attempts to treat desert bighorn sheep Mountain, Bennett-Goat Mountains, Ash-Salt CanyonslBrushy (Ovis canadensis mexicana) on the San Andres Mountains, Mountain, San Andres Mountain, and Onate-Block Mountains. New Mexico, for a severe infestation of scabies mites In 1976, 206 sheep occurred in these ranges. Following the (Psoroptes ovis Hering), 25 sheep were fitted with transmitter decline only 31 sheep were accounted for. Sheep remained in collars. Movemeqt and mortality data on desert bighorn sheep all areas except Brushy Mountains. were collected from 9 December 1980 to 25 March 1981. Seven of the collared sheep were killed by mountain lions (Felis concolor). Locations of 12 reintroduced sheep showed a tendency to seek out former home ranges.

The San Andres Mountains are located approximately 32 km northeast of Las Cruces, New Mexico, in Dona Ana County (Figure 1). San Andres National Wildlife Refuge is located on the southern portion of the range and straddles the tops of 5 mountain complexes known as Bennett, Brushy, San Andres, Onate, and Block Mountains (Figure 2). The topography of the study area is described by Sandoval (1979). Bighorn sheep are generally found among the limestone cliffs on the east slopes of the San Andres Mountains. In 1979, the first indications of the infestation of psoroptic mites was discovered on rams hgrvested during a refuge hunt. Circumstances surrounding the-infestation and the subsequent treatment of this epizootic are described by Sandoval (1 980). I would like to thank New Mexico Game and Fish biologist An- dy Sandoval and Bosque del Apache National Wildlife Refuge manager Ron Perry and biologist Mike Hawkes for their assistance, information, and cooperation. Andy Sandoval supplied the figures used for this paper. This project was a cooperative effort involving the New Mexico Department of Game and Fish, the White Sands Missile Range, New Mexico State University, Colorado State Universi- ty, and the US. Fish and Wildlife Service.

MATERIALS AND METHODS Transmitter collars were placed on 25 desert bighorn sheep (18 adult ewes, 5 adult rams, and 2 ram lambs) amounting to 68% of the known San Andres population. Thirteen sheep were members of the remnant San Andres population that were not removed during 1979 salvage operations. The remaining 12 Figure 1. Map of southcentral New Mexico showing sheep were originally removed from the San Andres Mountains San Andres National Wildlife Refuge and during 1979 treatment operations, held at the New Mexico vicinity (Sandoval 1979).

-64- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS 7,500 Block Mountain 7.528

Onate Peak 7.250 San Andres Peak 8.239

San Nicholas 6,130

Goat Mountain 6.750 -,,/ Quartzsite Mou

Little San Nicholas Canyon

RELEASE SITE

Hatchet Spring Canyon1 7,006

Figure 2. Dispersal patterns of 12 desert bighorn sheep re-introduced on the San Andres Mountains on 8 January 1981.

Mortality. Seven collared sheep (5 ewes and 2 rams) were killed by mountain lions from 30 December 1980 to25 March 1981. Mountain lions (Felis concolor) were considered responsible for killing sheep if scats, puncture marks from lions, drag marks, lion tracks or caches were discovered at the site (Hor- nocker 1970). Based on rumen contents, the feeding patterns of all sheep killed were normal.

CONCLUSIONS Data to make definite conclusions about the San Andres bighorn sheep population are limited. However, mountain lion predation appears to be a severe limiting factor on the San An- dre~herd. Seven out of 25 collared sheep have been killed by a mountain lion. Initial movements of the 12 sheep re-introduced on theSan An- dre~Mountains after one year of confinement at the New Mex- ico Game and Fish propagation facility at Red Rock, New Mex- ico, showed a tendency to seek out former home ranges. Further conclusions about sheep populations dynamics on the San Andres Mountains will be made after sufficient data has been collected.

LITERATURE CITED Hornocker, M.G. 1970. An analysis of mountain lion predation upon mule deer and elk in the Idaho Primitive Area. Wildl. Monogr. 21:l-39. Sandoval, A.V. 1979. Preferred habitat of desert bighorn sheep in the San Andres Mountains, New Mexico. M.S. thesis. Colorado State Universitgy, Fort Collins, 314 pp. Sandoval, A.V. 1980. Management of a psoroptic scabies epizootic in bighorn sheep (Ovis canadensis mexicana) in New Mexico. DBC Trans., pp. 21-28.

DESERT BIGHORN COUNCIL 1981 TRANSACI'IONS -65- implant-marking rifle. The rifle fires a cellulose bullet im- NEW MEXICO BIGHORN pregnated with MK-933 (Ivermectin), which is systemic and dissolves in 4-8 hours (refer to Sandoval 1980). SHEEP STATUS REPORT During November 1980, 14 bighorn were captured from a helicopter using projectile syringes. Skin scrapings and hair samples were collected from 6 standard places. A known number of animals were treated with liquid Ivermectin, and the Andrew V. Sandoval remainder were treated with ballistic implants. Thirteen sheep Bighorn Sheep Project Leader were radio-collared for future monitoring. New Mexico Dept. of Game and Fish Forty-five days post-treatment, 4 sheep were re-captured, 2 Las Cruces, New Mexico which had been treated with implants and 2 which had been in- noculated with injectable Ivermectin. Figure 1 shows the Abstract. New Mexico's bighorn sheep (Ovis canadensis) degree of infestation in free-ranging desert bighorn during pre management programs include the treatment of free-ranging and post-treatment operations, based on actual counts of Psoroptic mite infested desert bighorn and determining the ef- mites, eggs, and nymphs. Note the absence of live adults, live fectiveness of treatment operations, habitat studies, rein- nymphs, and live couples following treatment. The relative ef- troduction programs, and predator control. Assessing the fectiveness of lvermectin in eradicating mites and degree of in- large-scale salvage operation in the San Andres Mountains is festation based on actual counts of mites, eggs, and nymphs difficult because the captive population suffered heavy mor- is presented in Table 1. These data indicate that ballistic im- tality from viral infections during confinement at Red Rock, plants are equally effective as injectable lvermectin in after they were presumed safe. A major accomplishment of the eradicating mites, and that degree of infestation varies among scabies epizootic was the testing of MK-933 (Ivermectin) on animals. This suggests that individual physiology might play a mite infested sheep, and determining the relative effec- major role in determining susceptibility, and that once an tiveness of this drug in eradicating mites. This provided the animal is exposed to scabies a certain amount of immunity is management tool and expertise to treat free-ranging bighorn if built up. a disease outbreak should recur. The most disheartening event with our desert bighorn was the die-off that occurred with the San Andres bighorn during confinement at Red Rock, after they were presumed safe. An out- In view of last year's dismal loss of 85% of the San Andres break of viral blue-tongue and contagious ecthyma reduced desert bighorn (0.c. mexicana) population (Sandoval 1980), the population by 600. The die-off started in late June, and it New Mexico's overall bighorn sheep programs may be describ- was initially thought that poisonous plants were responsible. ed as cautiously optimistic. This past year's activities include Serological tests confirmed viral blue-tongue afflicting mainly the treatment of free-ranging Psoroptic mite infested desert the adult population. Contagious ecthyma fatally afflicted 5 of bighorn and determining the effectiveness of treatment opera- 7 lambs which had been born at Red Rock. The surviving sheep tions, habitat studies, reintroduction programs, and predator were captured and inoculated, and no further losses occurred. control. The Department of Game and Fish felt a greater risk was The New Mexico Department of Game and Fish, in cooperation associated by keeping the few remaining San Andres sheep with the Bureau of Land Management, US. Fish and Wildlife confined at Red Rock and elected to transfer the surviving Service, U.S. Forest Service, and New Mexico State University animals back to their historic range on the San Andres Moun- is involved in a longterm program to re-establish bighorn on tains. In January 1981, 14 sheep were captured using a linear historic range where habitat conditions are or can be enhanc- collapsible net. None of the sheep were drugged. They were ed for sheep. Due to recent transplant efforts, Rock Mountain radio-collared and transported in an enclosed trailer to the San bighorn continue to increase in numbers and expand their range. Despite re-establishment efforts, intensive predator control, and the apparent succes~sfultreatment of the majority Table 1. Counts of Psoroptic mites in free-ranging of the San Andres population, desert bighorn are existing desert bighorn sheep during pre and post- precariously. This prompted the8tate Game Commission to treatment operations. classify desert bighorn as a state endangered species, thus clearing the way for additional funding and management pro- / grams for the animals. The scabies epizootic is under control Injected Implanted and appears to have run its course. More importantly, we now Animal ID Number Animal ID Number have the management tool and expertise to treat free-ranging bighorn if a disease out-break should recur. RESULTS Desert Bighorn Sheep. Live Adults 43a/ (O)! 0 (0) 38 (0) 9 (0) Our desert bighorn sheep programs have been centered in the southwestern part of the state. These programs include the Live Nymphs 58 (0) 0 (0) 19 (0) - (0) Live Couples dl 42 (0) 0 (0) 8 (0) treatment of free-ranging mite infested bighorn in the San An- - (0) dre~Mountains, the return of the surviving San Andres sheep Eggs 17 (0) 27 (0) 28 (0) - (0) from Red Rock to the San Andres Mountains, the monitoring of Dead Adults 219 (178) 0 (0) 27 (1) - (5) Dead Nymphs the San Andres population, a transplant on the Peloncillo 153 (101) 49 (0) 25 (1) - (2) Dead Couples dl 217 (0) 0 (0) 1 (0) - (0) Mountains, monitoring of the Big Hatchet population, and the maintenance of the breeding population at Red Rock. -a1 pre-treatment counts

bl- post-treatment counts San Andres Mountains. A total of 33 free-ranging bighorn in -cl data not available the San Andres Mountains have been treated for scabies from dl couples designated as one count a helicopter using a specially designed compressed air -

-66- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS Andres Mountains. The ewes and lambs were placed in the An agreement had been reached with the Arizona Department front compartment and the rams were placed in the rear com- of Game and Fish and U.S. Fish and Wildlife Service for a partment. The 2 smaller rams died enroute to the release site, cooperative program to supply New Mexico with desert apparently after being battered by the larger rams. bighorn for the Peloncillo Mountains. During November 1980, 12 ewes were captured in the Kofa National Wildlife Refuge Peloncillo Mountains. A major highlight with our desert and North Plomosa Mountains, Arizona. The sheep were ex- bighorn sheep program was a transplant on the Peloncillo Mountains. The Peloncillo Mountains are a narrow range rising amined by veterinarians. Horn, and body measurements and 457 m (1,500 ft.) above the Animas Valley on the east and the blood samples were taken. The sheep were inoculated against San Simon Valley on the west. They extend north from the contagious ecthyma, viral blue-tongue, and scabies. Radio col- border with the Republic of Mexico for 120 km (75 mi.) on both lars were fitted on all the animals. sides of the New Mexico-Arizona line. The mountain range is concave to the west with the southern tip extending into Two ewes have been lost. One sustained permanent neck Sonora, Mexico, and the northern tip extending into Arizona. damage when she hit the paddock fence. This animal was This was a paddock-type release, with the objective of im- treated by a veterinarian then transported to Red Rock where printing the sheep to an area having lambing ground she died six weeks later. The second ewe was found dead in- characteristics. The paddock is a temporary, completely port- side the paddock. A necropsy revealed extensive hemorrhag- able facility (Bavin 1980). To prevent lambs from becoming en- ing in the flank and lumbar region. A 10 cm (4 in.) tear in the tangled in the net tence, the bottom was lined with poultry muscle wall was found and peritonitis had set in. Probable wire. cause of death was due to a fall.

70 PRE-TREATMENT COUNTS 65 1-1 1-1 POST-TREAT COUNTS 60

40 zI- 35 nW 30

LIVE ADULTS LIVE COUPLES DEAD NYMPHS LIVE NYMPHS DEAD ADULTS DEAD COUPLES

Figure 1. Counts of Psoroptic mites in free-ranging desert bighorn sheep during pre and post-treatment operations, San Andres Mountains, New Mexico.

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -67- Table 2. Lambing dates for desert bighorn sheep Table 3. Bighorn sheep population estimates in New transplanted on the Peloncillo Mtns., Mexico. New Mexico.

Lambing Plastic Metal Year Estimates Apparent Date Age Radio Tag No. Tag No. Capture Site Area Released Numbers Trend

Jan 18 6 + 9.68 North Plornosa Mtns, Az Rocky Mountain Bighorn Jan 18 3.5 9.31 North Plomosa Mtns, Az Sandia Mountains 1941 30 Declining Jan 20 6+ 9.19 Kofa, NWR, Az San Francisco River 1964 150 lncreasing Jan 21 5+ 9.33 Kofa NWR, Az Turkey Creek 1964 25 Stable Jan 27 1.5 8.42 Kofa NWR, Az Pecos Wilderness 1965 225 lncreasing Mar 4 4 9.20 Kofa NWR, Az Wheeler Peak 1968 and 1970 25 Stable Mar 5 1.5 9.61 North Plornosa Mtns, Az Manzano Mountains 1977 and 1978 40 lncreasing Mar 8 6 + 9.65 North Plomosa Mtns. Az Latir Lakes 1978 35 lncreasing Cirnarron Canyon 1970 and 1978 Unknown Total 530

Desert Bighorn Eight lambs were born to the remaining 10 ewes in the paddock (Table 2). Two 1.5-year-old ewes lambed, indicating they San Andres Mountains Supplemented 1981 30 were serviced between 11 and 12 months of age. Note the Blgh Hatchet Mountains Supplemented 1979 30 Peloncillo Mountains snychrony of lambing within 2 distinct periods. 1980 18 Guadalupe Mountains -- 14 Unknown The population in the Peloncillos stands at 18 (10 ewes and 8 Red Rock Captive Population 39 - lambs), which are currently confined to the paddock. The Total 131 release from the paddock is scheduled for June. Prior to the 'Too recent to be evaluated release, we plan to transplant rams from Red Rock and release them in the paddock. The sheep will then be released as a group just before the mating season. We feel that the onset of have not been legally hunted since 1978, when mites were first the mating season will enhance group integrity, and the ap- discovered in the San Andres population. proaching warm season will localize the animals in proximity of the water catchment unit at the release site. CONCLUSIONS A predator control program was initiated immediately afterthe This report summarizes New Mexico's bighorn sheep restora- release. During the past 4 months, 4 mountain lions (Felis con- tion programs and current status. In order to fulfill our prin- color), 10 bobcats (Lynx rufus), and 24 coyotes (Canis latrans) cipal obligation to New Mexico's wildlife resources, the have been removed from the vicinity of the paddock. Department of Game and Fish has given its highest priority to meeting wildlife needs whenever the viability of a wildlife Big Hatchet Mountains. The recent supplement in the Big species is involved. To insure the continued existence of Hatchet Mountains (Sandoval 1979) has reversed the declining bighorn sheep, the most practical and feasible alternative is to trend in this population, and currently numbers30 animals. We establish new populations in areas identified as having the feel that this figure exceeds the minimum threshold between highest potential for perpetuating bighorn populations. survival and extinction; consequently, this population should continue to increase in numbers and distribution. Basically, 2 distinct populations occur in the Big Hatchets. The indigenous LITERATURE CITED sheep occupy the southern part of the range and the introduc- Bavin, B. 1980. Post-release study of desert bighorn sheep in ed sheep occupy the northern portion, with ram groups travell- the Big Hatchet Mountains, New Mexico. Desert Bighorn ing between the 2 (Bavin 1980). Council Trans., pp. 12-14. Red Rock. The Red Rock population currently numbers 39 Sandoval, A.V. 1980. Management of psoroptic scabies epizoo- sheep, with the sex ratio skewed towards males. During the tic in bighorn sheep (Ovis canadensis rnexicana) in New summer of 1980, 7 rams were taken to N.M.S.U. for cross- Mexico. Desert Bighorn Council Trans., pp. 21-29. transmission studies with Psoroptic mites. The removal of rams for the Peloncillo transplant will deflate the male seg- ment of the population to a more desirable level. Rocky Mountain Bighorn Approximately 530 Rocky Mountain bighorn are currently found in New Mexico. The largest concentrations are found in the Pecos Wilderness northeast of Santa Fe, and in the San Francisco River drainage in the southwestern part of the state (Table 3). The status of the Cimarron Canyon population is unknown. Up to 22 animals had been reported 2 summers ago. The majority of the sheep are presently unaccounted for. One radio-collared ram was killed by a vehicle, 1 radio is apparently nonfunctional, and the third collared sheep has not been located. Rocky Mountain bighorn are currently being hunted on a limited basis in the Pecos Wilderness and San Francisco River drainage. Hunter success has averaged 24 and 83% for the Pecos and San Francisco River, respectively. Desert bighorn -68- DESERT BIGHORN COUNCIL 1981 TRANSACTIONS Results from preliminary simulations with the new lamb sur- STATUS OF POPULATION vival regression are less clear than results reported by Leslie (1980), due to oscillations in population size. Yet, similar con- MODELING OF THE clusions can be drawn. First, they do not support the notion that a population will always recover within a few years after RIVER MOUNTAIN HERD removal of 40 animals, since recovery is dependent on the stochasticity of fall precipitation, as well as density. Secondly, the age structure of the simulated population never stabilizes, due to rapidly changing rates of increase. That indicates that heavy removal which concentrates on any particular age class of females will produce more dramatic oscillations. David M. Leslie, Jr. More simulation work is currently underway. It is hoped that Cooperative National Park Resources Studies Unit the revised model will allow managers to obtain sensible Dept. of Fisheries and Wildlife answers to such questions as "How will the River Mountain Oregon State University herd respond to the removal of 40 sheep given a particular fall Corvallis, OR precipitation regime?" Charles L. Douglas Cooperative National Park Resources Studies Unit LITERATURE CITED Dept. Biological Sciences Caughley, G. 1976. Wildlife management and the dynamics of University of Nevada, Las Vegas, NV ungulate populations. In T.H. Coaker (Ed.) Applied Biology Vol. 1, Academic Press, London, Eng., pp. 183-246. Leslie, D.M., Jr. 1980. Remnant populations of desert bighorn sheep as a source for transplantation. DBC Trans., Desert bighorn sheep (Ovis canadensis nelsoni) in the River Pp. 36-44. Mountains, Nevada, are maintained at an economic carrying , and C.L. Douglas. 1979. Desert bighorn sheep of capacity, as defined by Caughley (1976), by removal of sheep the River Mountains, Nevada. Wildl. Monogr. 66:l-56. for transplants. Since 1969, 102 sheep have been removed, 60 in the past 2 years. Because that level of harvesting greatly ex- McQuivey, R.P. 1978. The desert bighorn sheep of Nevada. ceeds the level harvested from any other population of the Nevada Fish Game, Biol. Bull. 6. 80 pp. subspecies, demographic behavior of the herd is being monitored by the National Park Service and the Nevada Department of Wildlife. A simulation model was developed (Leslie 1980) to aid in making proper management decisions regarding numbers of animals removed, and frequency of removal. This report summarizes our attempts at refining the original model (Leslie 1980). The original model suggested that a transplant comprised of a random selection of ewes from all age classes was the most pragmatic for both the source population and transplant group. However, Leslie (1980) cautioned that the simulations did not account for the effect of variability in climatic variables thought to limit lamb production and survival in low elevation ranges in southern Nevada. The unknown degree to which density-independent factors operated with density-dependent factors was a serious limitation of the model. We hypothesized that climate, particularly precipitation, has a direct effect on survival of lambs and may operate synergistically with or independently of density on a year to year basis. If a predictive model that incorporated both density and weather could be devised based on empirical observations from the River Mountains?it would greatly minimize limitations of the original population model. Therefore, a stepwise multiple regression procedure was used to examine the relationship between lamb survival (Y) in the River Mountains from 1969-1980 and density (Xi) and 8 weather variables (X2-Xg), including seasonal precipitation, minimum temperatures, and wind. Previous fall precipitation (i.e., precipitation one year prior to October lamb counts or when the ewe was gravid witn the observed lamb) and herd density accounted for 87-Y0 of the variability in lamb survival and provided a significant model (P <0.01). That regression model improves our ability to predict lamb survival, as it depends on fall precipitation and density, and causes random oscillations in the size of the River Mountain herd (Leslie and Douglas 1979, McQuivey 1978). Fall precipitation can be randomly generated each year of the simulation and becomes an important determinant in the rate of increase in the population after transplant removal.

DESERT BIGHORN COUNCIL 1981 TRANSACTIONS -69- ATTENDANCE ROSTER, DESERT BIGHORN COUNCIL 1981 -82

Bailey, James A., Dr. Haderlie, Milton (USFWS) Lange, Bob (NMG&F) Russi, Terry L. (BLM) Dept. Fish & Wildfe. Biology 2932 W. 20 Place 1480 N. Main 3623.H101 Canyon Crest Dr. Colorado State University Yuma, AZ 85364 Las Cruces, NM 88001 Riverside, CA 92507 Ft. Collins, CO 80523 Hamilton, Kathy (NPS Coop Unit) McClure, Richard Sanchez, Peter G. (NPS) Barrett, Jim W. (AG&F) Dept. Biological Sciences Box 234 P.O. Box 276 P.O. Box 134 University of Nevada Monticello, UT 84535 Death Valley, CA 92328 Payson, AZ 85541 Las Vegas, NV 89154 McCutchen, Henry (NPS) Sandoval, Andrew V. (NMG&F) Bates, Bill Hansen, Mike (USFWS) 1301 Village Lane 1480 N. Main Dept. Wildlife Science P.O. Box 1297 Ft. Collins, CO 80521 Las Cruces, NM 88001 Corvailis, OR 97330 Utah State University Mclntyre. Rick (NPS) Logan, UT 84322 Schulze, Richard (UDWR) Holmes, Ken (ELM) Box 327 Box 851 Bavin, Bob (NMG&F) 1705 North Valley Death Valley, CA 92328 Monticella, UT 84535 St. Rt. 1, Box 158D Las Cruces, NM 88001 McKnight, Doug Deming, NM 88030 Scott, Joan E. (SCBS) Jacot, Francis H. (NPS) 277 W. 500 No. 1141 N. Park Ave. Belknap, Don (AG&F) 133 Gough St., No. 2F St. George, UT 84770 Pomona, CA 91768 San Francisco, CA 94109 1057 E. Watson Dr. McQuivey, Robert T. (NDW) Tempe, AZ 84182 Seegmiller, Rick F. Janke, Douglas (BLM) 4411 Pineaire St. College of Forest Resources AR.10 Blaisdell, James A.(Retired NPS) 4771 Woodlake Las Vegas, NV 89117 Univ. of Washington 5425 Indian Beach Lane Las Vegas, NV 89117 Mahon, Carl L. (ELM) Seattle, WA 98195 Friday Harbor, WA 98250 Jenner, Charles W., D.V.M. 439 N. 600 W., No. 11 Shields, Paul W. (USFS) Branham, Bud (Adventure Unltd.) (Soc. Conserv. Bighorn Sheep) Cedar City, UT 84720 5813 Village Way P.O. Box 27 11381 Loch Lomond Rd. Mahon, LaVeda Ogden, UT 84403 Hurricane, UT 84737 Los Alamitos, CA 90720 439 N. 600 W., No. 11 Snyder, Walter A. (NMG&F) Brlgham, Will R. (BLM) Jensen, F.Clair (UDWR) Cedar City. UT 84720 1103 Siringo Ct. Box 606 P.O. Box 1806 Maiey, Mark R. (ELM) Santa Fe, NM 87501 Carson City, NV 89701 Cedar City, UT 84720 2000 N. Wihwood Sykes, C.D. (BLM) Bunch, Tom, Dr. (UT State Univ.) Las Vegas, NV 89108 P.O. Box 691 1161 N. 1520 E. Battle Mtn., NV 89820 Logan, UT 84321 Trethewey, Ralph Burke, Bill 643 Ave. "F" 601 Nevada Highway Boulder City, NV 89005 Boulder City, NV 89005 Turner. Jack C., Dr. (Denver Univ.) Carpenter, Lewis E. (SCBS) 1557 N. 15th 815 W. Gettysburg Laramie, WY 82070 Fresno, CA 93705 Voget, Ken (USFWS) Carpenter Marguerite P.O. Box 111 815 W. Gettysburg Lakeview, OR 97630 Fresno, CA 93705 Warren, R.L. Chilelli, MaryEllen (Univ. AZ) 7439 S. 2300 E. 3401 N. Columbus, No. 14E Salt Lake City, UT 84121 Tucson, AZ 85712 Watt, Larry (AG&F) Cooper, Jack (NDOW) 1265 N. 24 St. State Mail Room Complex Mesa, AZ 85203 Las Vegas, NV 89158 John, Rodney T. (UDWR) Monson, Gale Weaver, Richard A. (CDF&G) Dee, Michael (L.A. Zoo) 955 E. 13800 So. 8831 N. Riviera Dr. P.O. Box 1383 524 Irving Ave. Draper, UT 84020 Tucson, AZ 85704 Loomis, CA 95650 Glendale, CA 91201 Wells, Michael L. Jones, Derris R. (UDWR) Morgart, John R. (BLM) DeForge, James R. (SCBS) Box 99 P.O. Box 692 P.O. Box 428 Ana-Borrego D.S.P. Borrego Springs, CA 92004 218 E. J St. Blanding, UT 84511 St. George, UT 84770 Ontario, CA 91764 Welsh, George, W. (AG&F) Jurgens, Bob (SCBS) Musick, Steve 2521 Valentine Ave. deVos, James D. (AG&F) 1850 Hualapai Dr. (Judith River Ranches, Inc.) Kingman, AZ 86401 P.O. Box 5751 Riviera, AZ 86442 Box 384 Yuma, AZ 85364 Hilger, MT 59451 Kay, Dennis (UDWR) West, Robert L. (TX P&W) Dills, Kim (Univ. of WY) Box 400 Olech. Lillian A. (BLMI 3825 Deerfield .. San Angelo, TX 76901 1557 No. 15th Washington, UT 84780 333 S. ~aterman~ve: Laramie, WY 82070 El Centro, CA 92243 Wilson, Lanny 0. (BLM) Kelly, Warren E. (USFS) 311 Parkway Dr. Doddridge, Henry (SCBS) Spring Creek Box 1057 Peepies, Tommy (AG&F) Boise, ID 83706 151 So. Villa Elko, NV 89801 2071 E. 25th PI. Fresno, CA 93727 Yuma, AZ 85364 Witham, James H. (Biologist) Kerr, Caritas R. P.O. Box 330 Douglas, Charles L., Dr. (NPS) (UT DBS Soc.) Perry, Ronald L. (USFWS) Quartzsite, AZ 85346 1444 Rawhide Rd. 125 S. 350 E. P.O. Box 1246 Boulder City, NV 89005 Orern, UT 84057 Socorro, NM 87801 Wood, Mawin (SCBS) 19 Byron Dr. Dunn, Bill (NPS Coop Unit) Kerr, Richard E. Pulliam, Dave (BLM) Lemoore, CA 93245 Dept. Biological Sciences (UT DBS Soc.) 601 Greenhurst Rd. University of Nevada 125 S. 350 E. Las Vegas, NV 89128 Yoder, Robert G. (USFWS) Las Vegas. NV 89154 Orern, UT 84057 Purdy, Ken G. (U of AZ) 1500 N. Decatur Blvd. Las Vegas, NV 89108 Ginnett, Tim (NPS Coop Unit) Kiipatric, Jack (TX P&W) 325 Biological Sci. E. Dept. Biological Sciences Box 1228 Univ. of AZ Young, Rob (AG&F) University of Nevada Marla, TX 79843 Tucson, AZ 85721 Box 2954 New River S. Sage Las Vegas, Nevada 89154 Phoenix, AZ 85029 Kisler. Earl M. (USFWS) Remington, Richard (AG&F) Glaze, R.L., DVM 1500 No. Decatur 3005 Pacific Ave. Zeiler, Bruce L. (USFWS) Star Rte., Box 6458 Las Vegas, NV 89108 Yuma, AZ 85364 1500 N. Decatur Kerrville, TX 78028 Las Vegas, NV 89108 Kovach, Steven D. (NAS, Pt. Mugu) Roberson, Jay A. (UDWR) Guymon, Jim (UDWR) 2105 N. Ventura Rd, No. A 244 S. 100 W. Zeman, Lloyd (Foundation 90 So. 200 W. Oxnard, CA 93030 Price, UT 84501 for No. Amer. Wiid Sheep) Parowan, UT 84761 Rundell, Linda (BLM) 55 West ivy Krausman, Paul R., Dr. (U of AZ) St. Paul, MN 55117 Hawkes, Michael (USFWS) 7101 E. Eli Place 2050 Magic Way, Sp. 38 604 Loma Encantada Tucson, AZ 85710 Henderson, NV 89015 Socorro, NM 87801

-70- DESERT BlGHORN COUNClL 1981 TRANSACTIONS INSTRUCTIONS FOR CONTRIBUTIONS TO

THE DESERT BIGHORN COUNCIL TRANSACTIONS *

General Policy: Original papers in the field of the desert bighorn References: When there are less than three references, insert sheep and its habitat are-publ~shedin the DESERT,BIGHORN them in parentheses where needed in the text by author, year, COUNCIL TRANSACTIONS. All papers presented at the publication, volume, and pagination. Three or more references Council's annual meetings are eligible for publication. Additional are grouped alphabetically by authors' last names under papers may be published when reviewed and approved by the "Literature Cited". Use initials only for given names of authors, Transactions Committee. Papers in excess of 10 pages a copy will except for women's names, which will be spelled out. Cite books be charged to the author at the current cost per page unless as follows: authors, date, title, publisher, place and paging. authorized by the Transactions Committee. Papers must be Paging must accompany direct quotes. To facilitate search of the submitted to the Editor at the Council's annual meeting to be literature it is highly desirable that paging be shown for considered for the current edition. paraphrased citations within the text. Show number of pages in theses. When necessary it is permissible to cite unpublished Copy: Type manuscripts double space throughoutwith 11%-inch reports. Include source, paging, kind of reproduction (type- margins all around on goodquality paper8Y~x11 inches. Number written, mimeographed, or multilithed), and place where filed. pages in upper right-hand corner. Proceed from a clear statement of purpose through procedures, results, and discussion. Tables: Prepare tables in keeping with the size of the Sequence of contents: abstract, introduction, materials and TRANSACTIONS pages. A good table should be understandable methods, results, discussion, literature cited, tables and figures. without reference to the text. Long tables are rarely of general Type author's complete address on upper left-hand corner of first interest, short lists, with pertinent comments, are preferable. page. The author's name and his affiliation at the time the paper was performed follows the title. Present address, if different, Illustrations: Illustrations should be suitable for photographic should be indicated in a footnote on the first page. reproduction without retouching or redrawing (see the TRANSACTIONS for examples). Illustrations exceeding 8% x 11 Style: Guides to the rules for preparation of copy (capitalization, inches are not acceptable. Line drawings or graphs should be in abbreviation, punctuation, tables, formulas, and literature cited) India ink, on whitedrawing paper. Only essential photographsfor are the Style Manual for Biological Journals (prepared by the half-tone illustrations will be acceptable because of the cost of Committee on Form and Style of the Conference of Biological reprod~ction.Submit prints of good cantrast on glossy paper and Editors). Consult the 1967 TRANSACTIONS for examples of properly label. prevailing style. The authority for spelling is Webster's Third New International Dictionary, unabridged. Proof: All papers will be reviewed for acceptable format, by the Transactions Committee. Submit papers; to the Editor, Death Title: The title should be concise, descriptive, and not more than Valley National Monument, Death Valley, CA 92828. Should 10 words in length. Avoid scientific names in titles if possible. papers be returned to authors for minor format corrections, please return corrected manuscript within 30 days. Footnotes: In general, avoid footnotes by incorporating such material in the text. Reprints: Minimum orders of reprints are available at printing costs providing the author submits his requests at the time of Acknowledgements: Include acknowledgements at theend of the submission of manuscript. introduction. EditorialPolicy: All manuscripts submitted for publication will be Scientific Names: Vernacular names of plants and animals are reviewed by the Transactions Committee. The committee will accompanied by appropriate scientific names the first time each primarily review all papers for format (in accordance with these is mentioned (see Style Manual for Biological Journals). instructions), and secondly will, when deemed necessary, provide advice only on contents. Abstract: Instead of a summary, an abstract should accompany all articles. The abstract should be an informative digest of significant content. It should be able to stand alone as a brief statement of the conclusions of the paper.

*Approved by Council at 1966 Annual Meeting, amended April 6, 1967.