The Effects of Herbicide Applications on the Animal Populations of Aspen Communities

Brigham Young University BYU ScholarsArchive

Theses and Dissertations

1970-08-01

The effects of herbicide applications on the animal populations of Aspen communities

Carl Eugene Wadsworth Brigham Young University - Provo

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BYU ScholarsArchive Citation Wadsworth, Carl Eugene, "The effects of herbicide applications on the animal populations of Aspen communities" (1970). Theses and Dissertations. 7911. https://scholarsarchive.byu.edu/etd/7911

This Dissertation is brought to you for free and open access by BYU ScholarsArchive. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. THE EFFECTSor HERBICIDEAPPLICATIONS ON THE ANIMALPOPULATIONS or ASPEN cororoUNITIES

A Dissertation Presented to the Department of Zooiogy and Entomology Brigham Young University

In Partial fulfillment of the Requirements for the Degree Doctor of Philosophy

by Carl E. Wadsworth August 1970 This dissertation by Carl E. Wadsworth is accepted in its present form by the Department of Zoology and Entomology of Brigham Young University as satisfying the dissertation requirement for the degree of Doctor of Philosophy.

Typed by Vanda F. Wadsworth iii

ACKNOWLEOGfflENTS

To Dr. c. Lynn Hayward, who served as my graduate committee chairman, and Dr. Odell Julander, committee mem- ber, I express sincere appreciation for the valuable assistance and advice given during the research and preparation of this dissertation. Gratitude is also extended to Or. Armond T. Whitehead of my graduate committee for his read- ing and criticism of the manuscript. I wish to express appreciation to the u.s. rarest Service, Fishlake National Forest, notably, max E. Robin- son and James L~ Mower, for their support, incouragement, and assistance during this study. Grateful acknowledgment is also expressed to others who contributed to the successful completion of this work: monte Roe for his assistance in handling the computer pro- graming of the data on the mammals and the Brigham Young University Computer Center for its services; Dr. v. m. Tan- ner for identification of the Orthoptera, or. IYI.w. Nielson for identification of the Cicadellidae, Dr. G. E. blallace for identification of the Ptaromalidae, Dr. c. w. Sabrosky, Dr. G. Steyskal, and Mr. w. E. Ma~his for identification of Oiptera, and Parly Winger for identification of the·aq~atic invertebrates. This study was support~d, in part, by a National !· . Defense Education Act fellowship. iv

TABLEOf CONTENTS

Page ACKNOIAILEDGmENTS• • • • • • • • • • • • • iii LIST Of TABLES • • • • • • • • • • • • • V LIST Of' ILLUSTRATIONS • • • • • • • • • • • vii INTRODUCTION• • • • • • • • • • • • • • 1 REVIEWOF' LITERATURE • • • • • • • • • • • 3 STUDYAREA • • • • • • • • • • • • • • 8 METHODS• • • • • • • • • • • • • • • • 12 Weather Data • • • • • • • • • • • 12 Soi 1 Arthropods • • • • • • • • • • 12 foliaga Insects • • • • • • • • • • 13 Aquatic Invertebrates • • • • • • • • 14 Birds • • • • • • • • • • • • • • 15 Small Mammals • • • • • • • • • • • 16 Large mammals • • • • • • • • • • • 18 Statistical Test of means • • • • • • • 18 Similarity of Study Plots • • • • • • • 19 RESULTS• • • • • • • • • • • • • . ,, • • 20 Weather Data • • • • • • • • • • • 20 Soil Arthropods • • • • • • • • • • 22 foliage Insects • • • • • • • • • • 25 Aquatic Invertebrates • • • • • • • • 30 Birds • • • • • • • • • • • • • • 34 Small IYlammals • • • • • • • • • • • 55 Large mammals • • • • • • • • • • • 64 DISCUSSION• • • • • • • • • • • • • • • 70 SUPIIYIARY• • • • • • • • • • • • • • • • 87 LITERATURECITED • • • • • • • • • • • • • 92 V

LIST or TABLES

Table Page 1. monthly weather data from Gooseberry Ranger Station during the summer of 1968 • • • • 20 2. Weekly weather data during the summer of 1969 ••••••••• • • • • 21 3. Average precipitation in inches per month on Sheep Creek Watershed during the summers of 1968 and 1969 •••• • • • 22 4. Average numbers of soil arthropods per sample in aspen study plots •• • • • • 23 s. Average numbers of soil arthropods per sample in meadow study plots •• • • • • 26 6. Average numbers of foliage indicator insects per sample from aspen study plots •• • • 27 7. Average numbers of foliage indicator insects per sample from meadow study plots •• • • 29 a. Analysis of water from rarnsworth Creek and Sheep Creek •••••• • • • • 31 Average numbers of aquatic invertebrates per sample from rarnsworth Creek and Sheep Creek ••••••••••• • • 32 10. Average numbers of the most common birds seen per day on the transects in 1968. • • 36 1 1 • Average numbers of the most common birds seen per day on the transects in 1969 • • • 37 12. Small mammal population estimates on aspen trapping grids in 1968 • •••• • • • 57 13. Small mammal population estimates on aspen trapping grids in 1969 ••••• • • • 58 14. Small mammal population estimates on meadow trapping grids • ••••••• • • 59 vi Table Page 15. Average number of pocket gopher mounds and earth plugs per transact ••••• • • 62 16. Estimates of the summer animal-days use per acre by deer and elk. • • • • • • 69 17. Percent similarity between soil arthropod populations on the aspen study plots • • • 71 18. Percent similarity between soil arthropod populations on the meadow study plots • • 72 19. Percent similarity between foliage indicator insect populations on aspen study plots •· •••••••••• • • 74 20. Percent similarity between foliage indicator insect populations on meadow study plots ••••••••••• • • 75 21. Percent similarity between aquatic invertebrate populations in Farnsworth Creek and Sheep Creek •••••••••••• • 77 22. Percent similarity between bird populations on the transects ••••••• • • 78 23. Percent similarity between small mammal populations on aspen trapping grids • • • 81 vii

LIST or ILLUSTRATIONS

Page

1. Sheep Creek Watershed ••••••• • • 11 2. Average number of soil arthropods per sample in aspen study plots •• • • • • 24 3. Average number of soil arthropods per sample in meadow study plots • • • • • 24 Average number of foliage indicator insects per sample in aspen study plots •• • • 28 s. Average number of foliage indicator insects par sample in meadow study plots •• • • 28 Average number of aquatic invertebrates per sample from rarnsworth Creek and Sheep Creak ••••••••• • • 34 Avar~ge number of birds seen per day on the transects ••••••• • • • 35 a. Small mammal population estimates on the aspen trapping grids ••••• • • • 56 9. Population estimates of Eutamias minimus on the aspen trapping grids ••• • • • 61 10. Population estimates of Peromyscus maniculatus on the aspen trapping grids • • • • • • 63 11. Population estimates of Migrotus longicaudus on the aspen trapping grids •••• • • 64 12. Population estimates of Zapus princeps on the aspen trapping grids •• • • • • 65 INTRODUCTION

man has repeatedly modified his environment by altering the soil systems, introducing new habitats, alter- int those already established, and retarding succession to favor his social and economic needs; the Sheep Creek Water Evaluation Project is a good example of this. The Sheep Creek Water Evaluation Project, located 17 mi southeast of Salina, Sevier Co., Utah, was started in 1957 by the U.S. forest Service to determine what effect manipulation of vegetation might have on water yield, stream regimen, and water quality. Approximately one-half of Sheep Creek Watershed has been left untreated, while the vegetation of the remaining portion has been drastically changed from aspen and oak to grass type community as a result of applications of herbicides in June and August 1965 and May 1966. Since the beginning of the Sheep Creek Water Eval- uation Project in 1957, the u.s. forest Service has collected data from stream and precipitation gaging stations, soil moisture plots, and has established and mapped vegetative types, but no extensive investigation of the animal residents was originally planned. The purpose of my study was to determine and compare the animal populations of the treated and untreated areas, and to evaluate the effects that 2 herbicides applied to aspen communities have on the animal populations of these areas. On the Sheep Creek Watershed there were untreated areas of the same community types having similar topogra- phic features as the treated areas. These offered an excellent opportunity to compare, not only the plants, but the animal residents of the two areas, and to establish ecological base lines for a better understanding of both un- disturbed and treated watersheds, The results of this inves. tigation should supplement and add significant basic ecolo• gical data to that collected by the u.s. forest Service to assist in more accurately establishing the complete ecological picture of the watershed, and should be important in determining the interrelationships of vegetation manipulation and the increase or decrease of animal species in tHe treated areas. Also, of fundamental importance in this study, is the added knowledge that can provide valuable assistance in future planning of ecological modification to better manage areas to favor man's economic and social needs, while wisely using renewable natural resources. 3

REVIEWOF LITERATURE

The aspen and oak communities in central and eastern Utah have been described by Hayward (1945 and 1948) and the effects of herbicides on plants in aspen communities have

been reported by Day, Hammer, and Panshin (1952), but no comprehensive studies on the animal populations in aspen areas treated with herbicides have been made. The auxin herbicides, 2,4-0 (2,4-dichlorophenoxyacetic acid) and 2,4,5-T (2,4,S-trichlorophenoxyacetic acid), have been found to be toxic to man and animals, but at concentra- tion levels far above those which are normally found in the enviornment immediately after application in most weed control operations (May, 1969). The danger of chronic toxicity to animals is also very low, and continuous high dosing over periods of months, rather than weeks, is required to produce severe symptoms of poisoning, As May (1969) has stated, "The principle problem from the use of auxin herb- iciides in relation to wildlife, is not toxicological but ecological in terms of scale and intensity of use, especially on nan-agricultural land •••• The hazard from the use of herbicides lies in the fact that they can now be used to affect vegetation over very wide areas in a short period of .time, thus, eliminating •reservoirs' of wildlife and wildlife habitat that would have otherwise survived." 4 Persistence of active 2,4-D in soil under field conditions has been reported by Ogle and Warren (1954) to last from less than 10 days to as long as 14 weeks. Differences were due to soil types, rainfall, temperature, and application rates. Bollen (1961) and Audus (1964) have concluded that of the many pesticides applied to the soil, the auxin herbicides, based on phenoxyacetic and propionic acid, were the most susceptible to breakdown by microorganisms. Davis (1965) was unable to show any differences in soil populations of Acari and Collembola species between untreated plots and plots that had been sprayed with fflCPA, (a butyric acid analogue of 2,4-D), in 10 out of 13 years. He was also unable to find any reports of significant effects on soil animals in other experiments of a similar nature. May (1969) reviewed some of the literature on the effects of herbicide applications on aquatic organisms, and concluded that most fish are unlikely to be affected by 2,4-D, 2,4,5-T, or MCPAat rates of application used for aquatic weed control. Hanson (1952) reported 2,4-D treatment of North Dakota marshes produced a heavy kill in broadleaf plants, but the only animals killed were a few insects, presumably from the oil in the treatment mixture. In their investigations into the effects of the use of 2,4-0 at rates from 40 to 100 pounds per acre in Tennessee Valley Authority reservoirs, Smith and Isom (1967) found no measurable toxic effect on benthic fauna or significant changes in mean numbers of burrowing mayflies (Hexagenia) before or after treat- 5 ment. Observations of free living fish indicated that they appeared to move out of the treated area, and analysis of a number of fish for 2,4-D residues gave no measurable results at the limit (0.14 p.p.m.) of detection (Smith and Isom, 1967). Deaths of bees have occurred following 2,4-D treatment of nectar producing plants when in flower, and it is possible that similar hazards exist for other nectar feed- . ing insects (Wahlen, 1950 and Antoine, 1966). Where other insects have been studied, increases in population have been noted more often than decreases (Robinson, 1959 and Maxwell and Harwood, 1960). Adams and Drew (1965) showed that the application of 2,4-D amine could enhance aphid infestation in grain fields, probably as a result of depressing the activities of coccinellid beetles preying on the aphids. Experiments dealing with herbicide toxicity and effects of herbicides on egg production and hatching rates

in chickens and turkeys have been reported by Dobson (1954), Roberts and Rogers (1957), and Dunachie and Fletcher (1967), but there have been no studies reported on the effects on bird populations. During the past two decades, herbicides have been widely used on rangelands of the western United States in attempts to improve range conditions, and some work has been done to determine the effects of range treatment with 2,4-D on rodent populations in western Colorado. Keith, Hansen, and Ward (1959) found that treatment reduced the density of 6 northern pocket gophers and that grass comprised a larger part of their diet on treated areas. Johnson (1964) reported that changes in the diets of deer mice and least chipmunks were correlated with increases in grass and decreases in forb production following treatment. Montane voles continued to subsist on leaves and stems of forbs and shrubs, even- though these plants were less abundant following treatment. Hansen and Ward (1966) and Tietjen §1 Al• (1967) observed that pocket gopher populations, initially reduced as a re- 1 sult of treatment, recovered with the reestablishment of per$nr,ial forbs on treated range. Tietjen .!!. ll• ( 1957) also found that captive pocket gophers sustained no direct toxic effects from ingestion of native plants treated with

2,4-D. Treatment seemed to have little effect on the abundance of deer mice (Peromyscus sp.) or meadow mice (migro- !.Y.! sp.) inhabiting the herblands they studied. Johnson and Hansen (1969) reported that the density and litter size of the deer mouse was little affected by 2,4-0 treatment, while the density of northern pocket gophers and least chipmunks was reduced, however, montane voles increased in abundanee following treatment. Mixtures of 2,4-0 and 2,4,5-T have been tes~ad by mueggler (1966) and Krefting and Hansen (1969) for effec- tiveness in lowering the live crown and increasing the basal sprouting of browse that had grown beyond the reach of deer and elk in northern Idaho. Thay reported that these animals selected treated plots over untreated plots for feeding, 7 however, these writers proposed cautious use of spray treatments because of adverse effects on many desirable plants other than the browse. 8

STUDYAREA

Sheep Creek Watershed is located in the Fishlake National Forest southeast of Salina, Sevier County, Utah (38047' North latitude and 111°41 1 West longitude). Eleva- tions range from 7800 ft a Gooseberry Ranger Station to

10,360 ft at the head of the 939 acre watershed. Physiographically the watershed is in the transition area between the Wasatch and Fishlake Plateaus; the regional geology is a broad, westward-tilted, monoclinal structure. Stratigraphic rock units are, from the highest to the lowest: late Tertiary volcanics, late Cretaceous and early Eocene shales, sandstones, limestones, and conglcmerates of the Flagstaff, North Horn, and Green River formations. Land slides, landflows, and slumps have strongly influenced the parent material from which the soils are formed. Parent materials on the upper portion of the watershed are generally volcanic; the lower areas, which include the major portions of the watershed, are chiefly of sedimentary ~rigin (Robinson, 1966). A distinct fault line runs parallel and adjacent to the major drainage, and some indications of recent faul- ting are evident. Water from sandstone and conglomerate. beds is released throughout the summer as seeps and springs

along and adjacent to the main drainage of the lower;•~. watershed~ 9 Soils are highly variable with a wide range of textures, depths, and drainage. Textures generally range from a loam or silt loam at the surface to clay loam and clays in the subsoil. Soils are moderately well drained to imper- fectly drained. Depts of soil range from 24 to 60 inches (Robinson, 1966). The mean precipitation, based on al July through 30 June water year basis, for the entire watershed from 1957-58 through 1966-67 was 27.8 inches, with a low of 21.0 inches in 1962•63 and a high of 35.0 inches in 1964-65. Water in the spring snow pack, based on means from two snow courses weighted according to elevation, averaged 15.6 inches during the ten year period (Robinson, 1966 and rorest Ser- vice records). rorest Service personnel completed a plant inventory in 1959 and found that the aspen community occupied 58% of the watershed, oak community occupied 15%, dry meadow (open forb-grass-shrub communities) occupied 22%, coniferous forest 4~5%, and wet meadow .1%. Ground cover (vegetation end litter), based on 154 permanent 100 ft 2 plots, averaged approximately 81% for all vegetative types, V~ry few plots, even in the dry meadows, had less than 40% ground cover and these bare areas ware generally occupied by rock. rorest crown cover, mostly aspen, averaged 49% for the watershed (Robinson, 1966; see Appendix I and II). The watershed is divided into 3 grazing compartments: (1) the entire upper (southern) half is used by Sheep from 10 approximately 15 June to 1 September, (2) the East side of the lower (northern} half is used by sheep and cattle from approximately 15 June to 15 September, and (3) the West side of the lower half is used by cattle from approximat~ly 1 September to 1 November. most of the data for the study were collected from this last compartment of the watershed which was kept free of domestic stock during may, June, July and August. Most of the lower half and a portion of the West· side of the upper half of the watershed (figure 1) was sprayed by helicopter with two pounds acid equivale~t of 2,4-0 and limited amounts of 2,4,5-T in diesel oil at the rate cf 3 gallons per acre. Applications of the herbicides were made on 23, 24, 29, and 30 June, and 25 and 26 :August 1965~ On 31 may 1966, approximately 100 acres of aspen near ' . the southwest margin of the weta~shed was resprayed, since applications the previous year failed to give complete de- foliation. The forest Service planned to maintain control of deep rooted vegetation for a period of 3 to 5 years, depending on the time needed to establish a basis for comparison of water yield from the two types of vegetations original deep rooted aspen-brush-herb type with more shallow rooted grass type expected to result from the spraying. No other herbicide applications have been made since 31 may 1966~ • The broad-leafed plants on 475 acres of the ~atershed were killed or defoliated as a result of herbicide applications, while 465 acres were left untreated for comparison purposes. 11

• Gooseberry Ranger Station 7,800 ft. Elev.

0 1200

Scale In feet

- Bird Transect ill! Mammal Trapping Grid • Aspen Study Plot "' Meadow Study Plot Vegetation Types 1. Forb-Grass-Shrub 2. Oak Brush 3. Aspen 4. Conifer

Fig. 1 • Sheep Creek Watershed. 12

METHODS

Weather Data

During the summer of 1968 little weather data were collected. A hygrothermograph, operated by forest Service personnel, was stationed just South of Gooseberry Ranger Station at the lower end of the watershed. The data from the instrument may be of little value to this study since is was located at an elevation 500 ft lower and 3/4 to l mile to the North of the actual study areas. During the summer of 1969, weather data were recorded by hygrothermographs located on the small mammal trapping grids of both treated and untreated aspen areas. Both in- struments were placed at ground level in protective struc- tures at 8,200 ft elevation and serviced weekly. There were four precipitation gauges located on the watershed which were serviced monthly by Forest Service personnel!

Soil Arthropods

Two arthropod study plots were established in each of the four vegetation types; treated and untreated aspen, and treated and untreated meadow~ These study areas were 150 x 150 ft and were chosen with the aid of forest Service 13 records and maps so that the treated and untreated plots of a particular type were as near alike as possible with respect to original vegetation, slope, and grazing history. All samples of soil arthropods and foliage insects were

taken 1from these study plots. Two sets of samples, five soil cores per set~ were taken per month at random from each of the eight study plots, totaling 20 cores from each treated and untreated vegetation ty~es. Each core was 3 inches (7.52 cm) in diameter and 3 inches deep (Ashley, 1968). The soil cores were en- closed in aluminum rings as they came from the sampler and were trao~ported to Provo in ice cream cartons or plastic bags~ Each core was then placed upside down on a layer of cheese cloth inside a modified Tullgren funnel (Park and Auerbach, 1954) for 48 hours. The funnels and extraction and counting methods were those described by Ashley (1968).

Foliage Insects

Since the vegetation of the treated portion of the watershed was almost exclusively grass, only the understory (to a height of about 3 ft above ground) was sampl~d in €he aspen areas. The only feasible means of sampling found was the sweep-net, The method used is a modification of one developed by Shelford and his students (Shelford, 1929) and has been criticized for its very evident limitations~ The criticisms and the literature with respect to subjectivity in sampling, effects of environmental factors, time of day, 14 and statistical analysis have been reviewed by Whittaker (1952). The net used in this study was 15 inches in diameter with a handle length of 24 inches. Twenty sweeps were considered one sample, but no attempt was made to convert this sample to a population approximation per unit area. Twenty sweeps from an untreated community type were compared with 20 sweeps from a treated area originally of the same community type. Eight samples per month were taken from each of the sample plots described in the Soil Arthropods section, totaling 16 samples from each treated and untreated vegetation type. The most common insects were identified to genus, where possible, counted, and used as "indicator insects" for comparison purposes.

Aquatic Invertebrates

Sheep Creek is a small permanent stream that runs from South to North the length of the watershed, but is located almost exclusively in the treated area, hence, the aquatic arthropods in treated and untreated areas could not be compared from samples taken from this creek. A small tributary of Sheep Creek originates in the untreated portion of the watershed, flows about¼ mi through the untreated area, and about¼ mi in the treated area before entering the main creek. This tributary appeared ideal to compare the aquatic arthropods of the two areas and was sampled in June 1968, but by 10 July 1968 the stream had dried up and could 15 not be used for future samples. rarnsworth Creek, located approximately l mi East of Sheep Creek on an untreated watershed, was sampled in July and August of 1968, and June, July, and August 1969, and the data compared to that collected from Sheep Creek during the same time periods. Areas 600 ft in length at an elevation of 8,100 ft were used along each creek as study areas. rour samples per study plot were made twice each month using a Surber square- foot stream bottom sampler. All organisms collected were identified to genus, counted, and the average numbers from the two creeks compared. Tests for alkalinity, hardness, turbidity, sulfate, ortho-phosphate and pH were made with a Hock Kit on water from rarnsworth and Sheep Creeks in August of 1968 and 1969.

Birds

Two transects, one in treated and one in untreated areas which had been previously established and permanently marked by rorest Service personnel, were 1,200 ft in length with stations spaced at 50 ft intervals. Reference points were marked, using red paint on trees, 75 ft on either side and parallel to these lines to produce transects 150 x 1,200 ft. The bird census procedure consisted of walking slowly through the center of the transect making stops {2 minutes) at-each station while recording every bird observed within the bounds of the transect. The census was made four consecutive days, 6:00 to 8:00 A.m. and 4:00 to 6:00 P.M. standard time, twice per 16 month. The transects were censused on an alternating sche- dule so that if the treated transect was censused from 6:00 to 7:00 A.M. and the untreated from 7:00 to 8:00 A.M. one day, the census sequence was reversed the next day. The same alternating sequence was followed in the afternoon censuses.

Small Mammals

Two trapping grids were established in the aspen community of the watershed, one each in the treated and untreated areas. The areas for these grids were chosen so that they were as near alike as possible with respect to original vegetation, slope, and grazing history as determined from u.s. forest Service records and vegetation maps.

Each grid contained 7 lines spaced 50 ft apart and each line included 7 stations, totaling 49 trapping stations. Two Young type live traps were used per station. Each grid was serviced simultaneously, once early each morning and once each evening, during the trapping periods to remove the captured animals and record data. The traps were then reset and rebaited with rolled oats. Animals caught for the first time were given a number by systematically clipping the toes as described by Speth (1969). The animal's number, the grid (control or treated), position on the grid, sex, age, repro- ductive activity, and time (morning or evening) were recorded for the first and all subsequent captures. These data for each capture were recorded on IBM cards for computer process- ing. 17 Three trapping periods were used during each of the summers of 1968 and 1969. The 1968 trapping periods consisted of five consecutive days each month: June, July, and August. The trapping periods were extended in 1969 to eight consecutive days each month. All traps were removed from the grids immediately following the August trapping period each summer since cattle were premitted to graze these areas beginning early in September. Two smaller grids were established in meadow areas, one in an untreated area and one in a treated area. Each grid consisted of four lines placed 50 ft apart and each line contained 4 stations, totaling 16 trapping stations. The trapping activities and the data collected were the same as on the larger grids in the aspen areas, except that the trapping periods were 29 July - 2 August 1968 and 28 July - 4 August 1969. An estimate of the number of animals on each grid was determined using Hayne•s (1949) modified ratio method. This method is described mathematically by the formula, P = rwx2/Iwxy where: P = an estimate of the population number, x • number of animals in the population that have been captured and marked, w = total number of animals in the sur- vey sample (includes both marked and unmarked animals), and y = proportion of w that are marked, determined with r/w where r = the number of recaptures in the sample. The pocket gopher populations were not studied extensively. Pocket gopher mounds and earth plugs on ten 18 randomly placed transects (50 x 450 ft) in each area, treated and untreated, were counted in late September of 1968 and 1969. These data were used as a general indication of pocket gopher activity during the previous summer. Specimens of mammals, birds and insects were pre- pared and deposited in their respective collections of the Life Sciences museum at Brigham Young University.

Large mammals

The summer use of the watershed by deer and elk was estimated by pellet group counts made late in September·qf 1968 and 1969. Ten transects of ten 358.15 ft 2 circular· plots (radius, 10.68 ft 2) were randomly placed in each area of the watershed, both treated and untreated. By using 13 fecal groups per animal-day, the count on one 358.15 ft 2 plot multiplied by ten, converts directly to animal-day use per acre. Thus, the number of fecal groups present on nne transect used in this study is the animal-days use per acre and the average of the ten transects in each area were used for comparison. The plot size, fecal groups per animal-day, and methods for sampling were taken from Rogers, Julander, and Robinette (1958) and Coles (1965). The presence of other large mammals on the watershed were determined from sightings and sign.

Statistical Test of means

The differences between the two sample means, treated and untreated, were tested wherever possible by , 19 t = (xt-ic)/sxt where: t = a calculated value to be compared with the cumulative i-distribution value at the 5% signifi- cance level, Xt = the sample mean of the treated study plot, x0 = the sample mean of the control study plot, and Sxt = the standard deviation of the treated mean (Ostle, 1963:113).

Similarity of Study Plots

The degree of similarity between treated and untreated study plots was calculated using the formula C = 2x/a+b where: C = coefficient of similarity, w = the sum of the lower of the two quantitative values for species shared by the two study plots, a= the sum of all values for the first plot, and b = the sum of all values for the second plot. The value of C varies from O for communities having no species in common, to 1.0 for communities identical both in species composition and in quantitative values for the species. Thus, the coefficient of dissimilarity equals one minus the coefficient of similarity. Although a maximum value~of 1~00 is theoretically possible, replicate samples for a single community usually show coefficients of only about a.as. A more realistic estimate of dissimilarity is obtai~•d, thereiore, if the coefficient of similarity i~ subtracted from a.as. These coefficients can be expressed either in absolute or relative form. The comparison of animal populations in different communities using a coefficient of similarity or dissimilarity has been done by Odum (1950) with birds and by Whit- taker (1952) with insects. 20

RESLILTS

Weather Data

The data collected from the hygrothermographs are presented in Tablas 1 and 2. In 1969 there were some impor-

Tabla 1. Monthly weather data from Gooseberry Ranger Station during the sumur of 19688 (7,800 ft elev).

June July August

Temp. Hum. Temp. Hum. Temp. Hum.

Average lllin. 39.10 4.so 41.88 10.a8 41.13 15.00 Average 59.65 29.60 60.41 34.53 56.81 37.40 Average Max. ao.20 54.70 78.94 58.19 72.50 59.80

8 Temp. • Temperature in °rand Hum.• Relative Hu•idity tant differences between treated and untreated areas with respect to temperature and relativs humidity. The minimum t~~perature of the treated station averaged 1.84° r lower than the untreated station, the temperature means of the two stations differed by less than 1° ton the average, and the maximum temperature of the treated station averaged 3~29° F higher than the untreated station. With respect to relative humidity, the minimum of the treated station averaged 16.16% lower than the untreated minimum, the mean of 21

8 Table 2. Weekly weather data during the summer of 1969 (8,200 ft elev).

Average IUn. Average Average l'lax.

IAleek Data Control Treated Control Treated Control Treated

B - 14 Temp. 37.41 36.93 50.20 51.02 63.14 65.21 June Hum. 39.42 14.62 59.73 sa.10 01.02 as.co

15 - 21 Temp. 39.00 37.75 51.75 53.63 64.50 67.50 June Hum. 37.50 28.00 5a.aa 56.00 80.25 84.00

22 - 28 Temp. 38.57 38.86 48.79 50.64 59.00 62.43 June Hum. 48.60 28.29 56.71 53.78 72.57 79.28

29 June - Temp. 44.14 42.43 59.78 59.64 75.43 76.85 5 July Hum. 30.14 21.86 52.07 43.85 74.00 65.85

6 - 12 Temp. 45. 71 42.00 59.57 58.78 73.43 75.57 July Hum. 31.00 20.43 54.14 53.21 77.29 86.00

13 - 19 Temp. so.oo 47.43 63.14 63.00 76.28 78.57 July Hum. 29.57 20.14 54.71 46.36 79.86 71.86

20 - 26 Temp. s2.oo 49.57 64.21 64.28 76.43 79.00 July Hum. 36.86 20.14 58c00 45.85 79.14 71.57

27 July - Temp. 52.22 51.29 63.70 65.29 75.52 79.29 2 August Hum. 42.80 16.29 61.50 45.36 00.20 74.43

3 - 9 Temp. 53.60 49.50 67.80 67.64 81.60 as. 11 August Hum. 29.00 1 o. 71 52.70 33.50 76.40 56.29 10 - 16 Temp. 49.86 48.57 62.57 64.07 75.29 79.57 August Hum. 28.29 20.29 53.10 45.00 78.14 69. 71

17 - 23 Temp. 49.00 45. 71 60.07 61.35 71. 71 77.00 August Hum. 35.51 14.43 57.71 42.93 80.29 71.43

24 - 30 Temp. 50.57 48.00 62.64 63.57 74.71 79.14 August Hum. 36.00 14.86 57. 71 43.14 79.43 71.43

8 Temp. • 0 r and Hum. = Relative Humidity 22 the treated averaged 11.15% lower than the untreated mean, and the maximum of the treated averaged 4.31% lower than the untreated maximum. The average rainfall per month for the watershed during the summers of 1968 and 1969 is presented in Table 3.

Tabla 3. Average precipitation in inches per month on Sheep Creek 8 lllatersbed during the summers of 1968 and 1969 •

IYlonth 1968 1969

IYlay 1.00 1.2a

June o.76 3.39 July 0.22 o. 71

August 2.13 1.12 September o.s4 1.aa

8 from U,S, forest Service records

Soil Arthropods

The soil arthropod population fluctuation patterns and the population differences between treated and untreated study plots were varied during the summer of 1968 in the aspen areas (Table 4 and Figure 2). The average number of soil arthropods per sample from the untreated aspen study plots ,was high in June., decreased in July, and increased in August, while the number per sample from the treated plots was moderately high in June, increased in July, and decreased in'August. The samples from the untreated aspen plots averaged more soil arthropods per sample in June and August 23

Tabla 4. Average numbers8 of soil arthropods per sample in aspen study platsb.

3968 1969 June Julx Au5a. June Julx Au511 C T C T C T C T C T C T

Acerina 105 50 60 98 24 30 15 65 108 95 39 63

Insacte 2 27 10 9 74 12 13 22 10 48 26 7 Collambolla 1 5 4 3 72 10 13 10 6 43- 25 3 Paduridae 3 1 2 62 5 2 1 5 29 13 2 Entoebryiidee 1 2 3 1 10 5 11 9 1 14 12 1 Thyaanoptera 1 18 3 5 2 2 10 4 5 1 4 Ha•iptare 4 3 1 2

Total 107 77 71 101* 98 42* 28 87* 118 143 65 70

8avaragae ot 20 samples per month from each area rounded to the nearest whole number

be• Control and T = Treated *Significant difference from tne control at the 5~ level

1968 then the treated plots, but the arthropod numbers from tre,ted plots were significantly greater in July than from the untreated plots. During the summer of 1968, the soil arthropod populations in the aspen study plots ave~iged 69% mites and 31% insects in the untreated area, and 74% mites and 26% insects in the treated area. During the summer of 1969, the soil arthropod populations in both treated and untreated aspen plots were low in June, increased in July, and decreased in August. The average number per sample from the treated plots was always greater than those from the untreated plots, but was significantly greater only during the month of June. The percent 24

Control ■ 150 Treated II

125

100

June July Aug. June July Aug. 1968 1969

fig. 2. Average number of soil arthropods per sample in aspen study plots.

Contro I ■ 150 Treated ■ 125

100

June July Aug. June July Aug. 1968 1969

Fig. 3. Average number of sQil arthropods per sample in meadow study plots. 25 composition of mites and insects in samples from treated and untreated aspen plots averaged near the same in 1969, with 76% mites and 24% insects in the samples from untreated plots, and 74% mites and 26% insects in samples from treated plots. The average number of soil arthropods per sample was always greater from the treated meadow study plots than from the untreated meadow (Figure 3 and Table 5) and, in 3 of the 6 months sampled, the difference was significant. In 1968, the samples from the treated meadow averaged 68% mites and 32% insects, while samples from untreated meadow averaged 69% mites and 31% insects. These percentages changed in 1969 to 74% mites in the treated plots and 84% mites in the untreated. The soil arthropod populations in both areas, treated and untreated meadows, were low in June, increased in July, and decreased in August during both summers.

Foliage Insects

The average number of foliage insects per sample was lower from the treated aspen study plots than from the untreated plots five of the six months sampled and, in four of the five months, the difference was significant {Table 6 and Figure 4). During the summer of 1968, the numbers of foliage insects on the untreated aspen plots were low in June, increased in July, and remained high in August, while in the summer of 1969, the foliage insect numbers in the same areas were very high in June, decreased in July, and continued to decrease in August. During the summers of both years, the numbers of foliage insects on the treated aspen 26

Table 5. Average numbers• of soil arthropods per sample in meadow study plotsb.

196§ 1969 Jung Jul! Aug1 Jung Juli Aug1 C T C T C T C T C T C T

Acarina 17 20 31 79 24 32 28 31 69 82 61 61

Insecta 5 22 15 22 12 18 4 16 12 21 8 24 Collembolla 1 3 10 14 10 12 3 6 9 16 7 16 Poduridae 3 7 4 4 2 6 1 Entomobryiidae 1 3 7 7 6 8 3 6 7 10 6 16 Thysanoptera 2 15 5 8 2 6 1 7 2 5 1 8 Hemiptera 2 4 3 1

Total 22 42* 46 101* 36 50 32 47 81 103* 69 85

8 averages of 20 samples per month from each area rounded to the nearest whole number be• Control and T • Treated *significant difference from the control at the 5%level plots were low in June, increased in July, and decreased in August. The main differences between treated and untreated aspen study plots can generally be attributed to two families of insects: Cicadellidae (especially Dikraneufa spp.) and Pteromalidae. Members of both families were present in relatively high numbers and consistantly in greater numbers on untreated plots. The average number of foliage insects per sample on treated meadow study plots was greater~than on the untreated plots five of the six months studied, and the difference was significant four of the five months (figure 5 and Table 7). Three families of insects ~ere important in producing the differences between the treated and untreated areas: Cicadel- 21

Tabla 6. Average numbars8 of foliage indicator insects per sample (20 sweeps) from aspen study plotsb.

1968 1969 June July Aug1 June Julz Asub Insect C T C T C T C T C T C T

Orthoptera Acrididae Chorthieeus 1 1 2 5 1 3 J111lanoelus 4 1 Hemipter, Lygaelclae 1 s Scutalleridaa 1 4 14 Cicadellidee Verdanus 2 7 6 2 3 94 12 18 28 12 8 O!kraneur1 22 84 70 22 119 59 50 8 76 8 24 4 Balcluthe 3 a 12 6 6 3 6 6 6 l~iDC8£US 10 10 10 16 4 130 14 32 40 4 Calaaptara ~ Coccinallidae 1 1 10 Curculionidae 14 2 4 1 2 2 2 Hy■anoptara Braconidaa 6 2 9 3 20 4 16 22 20 16 10 a Ichneumonidaa 3 2 5 2 8 6 8 2 4 2 4 Ptero■alidae lll1soeol0bu1 22 3 28 6 42 B 12 10 22 2 F'or11icidae 3 2 1 5 1 18 4 20 2 6 Vespidae 1 2 Oiptera Lauxeniidae lllin1tt&a 1 1 16 2 6 3 1 6 1 3 1 Chlaropidae Chlg£fU!S 5 3 1 1 2· 12 6 8 1 IIIX£DIIXZ8 1 1 2 4 2 2 Q11&01lle 1 3 12 4 3 4 1 3 10 5 5 2 Agramyzidaa 11 1 4 2 1 9 1 6 1 1 Antho■yiidae HYlemya 2 64 92 6 7 2 49 61 a 10 llltJacidae Caengs&a 2 4 3 3 4 2

Total 73 108 239 159* 226 102* 357 103* 255 191 147 88*

•averages af 16 samples per month from each area rounded to the neareat ■ bole number be ■ Control and T • Treated *Significant difference fram the control at the 6~ level 28

Control ■

350 Treated ■

300

250

200

150

100

June July Aug. June July Aug, 1968 1969

Fig. 4. Average number of foliage indicator insects per sample (2Q sweeps) in aspen study plots.

Contro I ■

350 Treated ■

300

250

200

150

100

June July Aug. ha ne July Aug. 1968 1969 fig. 5. Average number of foliage indicator insects per sample (20 sweeps) in meadow study plots. 29

Tuble 7. Average numbers8 of folia~e indicator insects per sample (20 sweeps) from meadowstudy plots.

l26~ 1969 June July Aug1 Jun1 July Aug1 Inaect C T C T C T C T C T C T

0rthaptera Acrididae Charthi12eus 2 1 4 5 2 3 1 2 4 12 4 6 1¥11lanoelus 1 3 4 1 3 1 4 10 2 6 Hemiptera Lygaeidae 39 12 3 15 1 21 18 2 4 Scutelleridae a 2 5 1 2 2 2 Cicidellidae Verganus a 2 26 44 10 23 11 2 38 4 40 18 Qikraneura 38 80 15 71 14 92 17 63 4 51 6 94 Balcluthe 4 6 2 22 9 31 3 a 2 13 19 lsli1:oc1rus 6 7 19 7 2 6 10 Coleaptera Caccinallidae 3 1 7 4 2 24 9 Curculionidae 6 4 2 3 10 4 Hymenoptara Braconidaa 30 4 6 4 6 3 23 6 18 8 4 10 Ichneumonidae 4 2 4 2 4 6 10 8 Pteromalidee Mgsaeolabus 4 7 32 6 30 4 1 6 8 18 26 f"ormicidae 2 2 2 3 14 2 2 1 2 2 10 4 Vaspidaa 1 2 2 1 1 0iptera Leuxaniidae !Unatt&1 18 4 8 2 4 1 11 3 6 1 Chlarapiclae Chloroes 2 2 2 7 3 10 1 2 2 6 8 13 IIIY[OIIYZ8 2 2 6 2 8 1 6 4 3 7 0scin1lla 4 6 9 13 6 18 3 5 10 16 8 13 Agramyzidae 2 1 3 2 1 4 1 Anthomyiidae Hylamyg 4 2 78 116 29 82 6 2 51 89 23 64 Muscidae Coenas&• 2 2 2 4 1 3 5 Total 143 120 206 353* 146 342* 99 104 199 243* 184 317*

•averages of 16 samples per month from each area rounded ta the nearest whole number be• Control and T • Treated *Significant difference from the control at the 5% level 30 lidae (especially Dikraneura spp.), Pteromalidae, and Antho- myiidae. members of each family were present in relati~ely high numbers and consistently in greater number on treated plots. During the summer of 1968, the average number of insects per sample on the untreated meadow was low in June, increased in July, and decreased in August, while on the treated plots, the insect numbers were low in June, greatly increased in July, and remained high in August. The average number of insects per sample during the summer of 1969 on the treated meadow was low in June, high in July, and remained high in August, whereas the numbers on untreated plots was low in June, increased in July, with further increase in August.

Aquatic.Invertebrates

The chemical analysis of water from Farnsworth and Sheep Creeks showed little difference in the tests conducted (Table 8). During the summer of 1968, the differences between the average numbers of aquatic animals per sample in the creeks on treated and untreated areas were significant in each of the three months (Table 9 and figure 6). The aquatic animal populations were greater in the untreated area than in the treated area in June and August, but less in July. These populations in the creek on the untreated area were high in June, low in July, and high again in August, while those of the treated remained near the same level in June and August with a slight increase in July. 31 Table a. Analysis of water from rarnsworth Creek (Control) and Sheep Creak (Treated).

27 August 1968 26 August 1969

Test Control Treated Control Treated

Alkalinity* 200 165 210 170 Hardness* Calcium 140 110 140 100 Total 220 240 210 240

Sulfate* 1 1 1 1 Ortho-Phosphate * 0.1s 0.1s 0.1s 0.20 Turbidity* 0 0-5 0 0-5 pH e.2 a.1 a.3 B.3 Temperature ** 48.0 49.6 49.0 52.D

*in parts par million **summer averages in °r taken each time aquatic animals were collected

The differences between average numbers of aquatic animals ,Per sample in treated and untreated areas in 1969 were contrary to those found in 1968. The numbers of aquatic ani~als from the creek on the treated area were significantly greater than those from the untreated creek in June and August, while the numbers from the creek of the untreated area were slightly greater in July. The aquatic animal numbers in the untreated area ware near the same low level in June and August, but increased in July, while those in the treated area were at the same relatively high level in June and August, but decreased in July. 32

Table 9. Average numbers8 of aquatic invertebrates per sample (1 ft 2) from Farnsworth Creek (Control) and Sheep Creek (Treated).

1968 1969 June Julx Aush June Jul! Aug1 Animal C T C T C T C T C T C T

Platyhelminthes Turbellaria 2 10 1 12 15 2 16 6 6 3 l'lollusca Gastropoda Graulus 1 1 1 Pelecypoda Sphaerium 2 Annelida Oligochaeta 1 1 1 2 Arthropoda Crustacea Ostracoda 6 8 Arachnida Hydracarina 3 1 5 1 Insects, Ephetnaroptera Heptageniidae Cinxgmula 3 28 41 61 4 26 12 14 12 16 Baatidae Ameletus 1 3 2 eaat:Ui 139 96 31 61 115 43 6 21 5 2 6 34 E9h1P!!fel la 4 19 2 6 3 27 3 13 2 8 Par1leptophlebia 3 1 Plecoptera Nemouridae Ng111oura 1 3 2 1 1 3 1 Pelidae Acroneuria 1 2 2 1 Pelodidaa Isogenus 6 12 7 6 2 1 4 1 3 9 Coleoptera Elmidae ,lmis 6 1 44 1 1 3 1 5 1

•averages of 8 samples per month from each area rounded to the nearest whole number 3:3

Table 9. (continued)

1968 1969 June Julx Aug1 ~ung Jul! AY!il1 Animal C T C T C T C T C T C T

Trichoptera Rbyacophillidae Rhx1caghill 3 16 1 7 4 5 7 6 2 2 GJigssaso111a 2 3 Psychomyiidae Pol%11Dtrogus 1 Hydropsychidaa Hxsftossxchg 6 Limnaphilidae Ngatht!f!!III 9 2 1 3 H11elEIE!hx!a;,s 1 1 Lapt0caride111 3 Brachycentridae B;achxcent;us 3 Oiptera Tipulidae Tipula 2 7 6 5 3 7 H111toma 1 2 Li111onia 2 Pedicia 1 9 3 Pilarie 1 f.;tioptara 1 1 Dixidaa R!Y. 3 Chironomidaa 88 52 15 21 2 8 1 1 9 10 2 Siawliidae SimuJiigm 5 3 1 Stratiemyidae 4 Rhagianiidae Atharix 1 Anthamyiidae 1

Total 236 1s1* 95 193* 232 156* 41 go* 87 62 49 97*

*Significant difference from the control at the 5% level 34

350 Control ■

300 Treated ■

250

200

150

100

June July Aug. June July Aug. 1968 1969 rig. 6. Average number of aquatic invertebrates per sample (1 ft 2 ) from Farnsworth Creek (Control) and Sheep Creek (Treated).

Throughout the study there were three groups of animals that were consistantly collected in greater numbers from the treated creek: (1) Cinygmula, (2) Ephemeiella, and (3) all members of the family Tipulidae. All other aquatic animals were collected in nearly the same numbers from both creeks or in greater numbers from the creek on the untreated area.

Birds

Populati ans

Figure 7 summarizes the average numbers of birds seen per day during each month of the summers of 1968 and 1969. During the summer of 1968, the differences between 35

Control ■

50 Treated

40 •

June July Aug. Sept. May June July Aug. Sept. 1968 1969

Fig. 7. Average number of birds seen per day on the transects (150 X 1,200 ft). the average number of birds seen per day on the treated and untreated transects were significant three of the four months (Table 10). The number of birds seen per day on the treated transect was less than the untreat~d in June, greater in July and August, and near the same in September. The average number of birds seen per day in 1969 on the treated transect was near the same as the untreated in May, less than the untreated in June, greater than the untreated in July and August, and less than the untreated in September (Table 11). Only in the months of June and August was the difference between the number of birds seen on the treated and untreated transects significant. 36

Table 10. Average numbas8 of the twelve most commonbirds seen per day on the transects in 19686 •

June July August September

Species C T C T C T C T

Broad-Tailed Hummingbird 1 1 1 3 2 (Selespborus plptycercus)

Red-Shafted flicker 2 1 1 1 2 (Colaptes cafer)

DownyWoodpecker 1 1 1 (Dendrocopos pubescans)

Western WoodPewee 2 1 7 1 9 (Contopua sordidulus)

Tree S11all0111 1 2 1 (Iridoprocne bicolor)

Black-Capped Chickadee 1 1 3 3 2 (Part1J atricapillus)

Hausa lllren 1 1 4 (Traglodvtee aedon)

Robin 4 1 2 1 1 1 (Iurdus migratorius) Pine Siskin 1 1 (Spinus pinus)

Gray-Headed Junco 13 3 4 1 5 2 11 9 (Junco caniceps) F'ox Sparrow 1 1 (Passarella iliaca)

Lincoln's Sparrow 2 1 7 1 9 (fflelospize lincolnii) Total 21 10* 11 24* 14 33* 14 13

•averages of 8 days observation in eacb area rounded ta the nearest ~bole number be• Control and T • Treated *Significant difference from the control at the 5% level 37

Tabla 11. Average numbe~s8 of tha twelve most commonbirds seen per day on the transacts in 1969.

lllay Jun• July August Sept1111bar

Species C T C T C T C T C T

Bra ■ d•T ■ ilad Hummingbird 2 3 4 3 1 1 (S1l••RbRFY•platxc1;cua) R ■ d•Shaftad r11cker 2 2 1 1 2 1 1 (Cplgpt11c1t1£> DownyWoodpecker 1 1 1 1 1 (Pfnd;qqoppspubasg1n1> We ■ tern WoodPa••• 15 5 2 1 5 3 4 CCpgtppy,1 eprdidylu • > T:11 Swallow 3 4 3 1 1 1 (Iridomco• bicglo;) Black-CappedChickadee 4 2 1 1 2 Ce■ rua 1tricap!lly1) HausaWren 1 2 1 1 1 2 Crrpglpaxt•seadqn) Robin a 6 3 2 1 1 1 1 1 (Ty;du1migratorius)

Pina Siskin 2 1 5 4 3 Cspinyapinue>

Cray-HaadedJunco 2 4 f:i 2 1 2 5 4 12 (Jyna,q1nicaps) F'cucSparrow 2 1 4 3 2 1 1 Total 20 22 40 2;* 24 31 11 25* 23 13

•averages of 8 days observation in each area raundad to tha 1a1r1at whala number be• Control and T • Tra1tad *Significant diffaranoa from the control at the 5~ level 38 Species

Turkey Vulture (Cathartes aura)

The turkey vulture was commonly seen soaring over the watershed in groups of 3 to 20, and were often seen perched on dead aspen trees in the treated portion. These birds ware seldom observed singly or in pairs.

Goshawk (Accipiter gentilis)

During both summers, goshawks were frequently observed on or near the watershed. These birds were most often seen in the vicinity of Gates Lake, located approximately½ mi South of the watershed. A pair of goshawks nested in this area each summer; two immature birds were seen with the adults from mid-July through August of 1968, and one immature was observed with the adult birds during July and August of 1969.

Cooper's Hawk (Accipiter cooperii)

During the two summers, cooper's hawks were seen only three times: 10 July 1968 flying above rarnsworth Creek½ mi East of Sheep Creek Watershed, 30 July 1968 flying above the treated portion of Sheep Creek Watershed, and 6 August 1969 flying above rarnsworth Creek. All observations were of single birds and for short periods of time~ , 39 Red-Tailed Hawk (Buteo jamaicensis)

Red-tailed hawks were commonly seen soaring above the watershed and in the general area, and were occasion- ally seen perched in aspen trees of both the treated and untreat~d portions. One pair nested in aspen trees along rarnsworth Creek each summer. One immature bird left the nest, located approximately 30 ft high in an aspen tree, 10 July 1968. In 1969, one young was reared in a nest located approximately 40 ft high in an aspen tree about 300 yds South of the nest used in 1968. This bird left the nest 9 July 1969. Two other immature hawks were seen several times in the untreated portion of Sheep Creek Watershed between 15 July and 2 August 1968.

Golden Eagle (Aguila chrysaetos)

Two golden eagles were seen soaring over and in the general area of Sheep Creek Watershed 30 and 31 July 1968, and a single bird was sighted soaring along a cliff line approximately 3 miles South of the watershed 19 July 1969.

Sparrow Hawk (ralco sparverius)

No sparrow hawks were sighted on the watershed or in the general area during the summer of 1968. An adult male was seen for the first time 4 June 1969 parched in a dead aspen tree of the treated portion of the watershed. On 8 July 1969, an adult male and female with three imma- 40 tures were seen either perched or flying in and around a small stand of dead aspen trees in the treated area. Adult and/or immature sparrow hawks were observed in the treated portion almost daily from the above date until approximately 25 August 1969, but all five were not seen again at the same time.

Blue Grouse (Oendragapus obscurus)

Only one blue grouse was seen during this study, an adult male 20 July 1969 on the ridge that is the East boundary of Sheep Creek Watershed at an elevation of 8,400 ft~

Ruffed Grouse (Bonasa umbellus)

Ruffed grouse were frequently seen in the untreated portion of the watershed. fflales were heard "booming" from early in June upon my arrival on the study area until 27 June 1968~ and from early may until 18 June 1969. The "booming" was heard almost at anytime during the day from approximately 6:00 A.m. until 7:30 P.ro. No nests were found, but hens with young were observed from mid-June until late August both summers. During the summer of 1968, eleven different hens with an average of six young, were seen on or in the vicinity of the watershed, while in 1969 only 5 ciff- erent clutches, averaging 4 young each, were observed in the same areas. On only three occasions were ruffed grouse seen ir the treated portion of the watershed: an adult hen 41 and 5 immatures seen in treat:ad aspen 22 August 1968, one adult male in a treated meadow about 20 yds from an untreated stand of aspen 8 July 1969, and a hen with 4 chicks in an untreated meadow 20 - 50 yds from a stand of untreated aspen each morning of 6 - 10 July 1969.

Spotted Sandpiper (Actitis macularia)

A pair of spotted sandpipers nested near a pond approximately¼ mi southeast of Gooseberry Ranger Station in June and July of 1968. Three young could fly well by 15 July 1968 and ware still present in the vicinity of the pond 8 August 1968. No spotted sandpipers were seen at this pond in 1969, but these birds nested and were very common at rarnsworth Lake, located approximately 2 mi southeast of Sheep Creek watershed. mourning Dove (Zenaidura macroura)

mourning doves were sighted twice during the summer of 1968, and three times in 1969. In 1968, one bird was seen in the vicinity of the ranger station on 25 June and on 25 July, whereas in 1969, three birds were seen in the treated area of the watershed: two on 4 June, one on 17 June, and two were seen in the untreated area 2 July.

Great Horned Owl (!Y!!.!:! virginianus)

One great horned owl was seen in the treated portion of the watershed 16 July 1968, and one was seen in the untreated area 25 July 1968. In 1969, two of these owls were 42 seen in the untreated area 10 July. Two small o•ls were sighted in the untreated area the night of 9 July 1969, but could not be identified.

Common;Nighthawk {Chordeiles minor)

During the summers of both years, common nighthawks ware not seen in the vicinity of the watershed until approximately 15 August. They were very numerous in flight during the early evening from approximately 15 - 25 August of both years, and decreased in numbers from 26 August, until there were none sighted after 1 September of either year.

Broad-Tailed Hummingbird (Selasphorus platycercus)

The broad-tailed hummingbird was common on the watershed and was observed in approximately equal numbers in both the treated and untreated portions. A female began sitting l July 1968 on a nest, that had been constructed the previous year, located on a conduit pipe extending from the ranger station house about 1 ft below the gable of the roof. Two young had left the nest by 12 August. A female began sitting on this nest again on 4 June 1969, but on 18 June the nest had been destroyed. On 18 June 1969, a nest containing two young was found approximately 10 ft high in a small aspen tree (4 inches in diameter) on the untreated small mammal trapping grid. These young hummingbirds were still in the nest 9 July, but had left 15 July, 43 Rufous Hummingbird (Selasphorus rufus)

On 17 July 1968, a pair of rufous hummingbirds were observed for approximately 10 minutes at the edge of an untreated meadow and a treated stand of oak brush. The male and female alternated between feeding from flowers in the meadow and resting on branches of dead oak bushes. Other hummingbirds were seen on the watershed, but positive iden• tifications could not be made.

Red-Shafted flicker (Colaptes cafer)

The flicker was the most common woodpecker of the watershed, and was most often seen in the treated portion.

Several nests were located in dead aspen trees, and by tbe middle of June of each year the adults were carrying food items to their nests. Young ware observed in nests as late as 3 August 1969.

Yellow-Bellied Sapsucker (Sphyrapicus varius)

The yellow-bellied sapsucker was uncommon on the watershed. This bird was seen in both treated and untreated areas of the watershed, but was observed more frequently in the untreated portion~

Hairy Woodpe9ker (O,endrocopos villosus) Hairy woodpeckers were not common on the watershed, but ware more oft~n observed in the treated area. 44 Downy Woodpecker (Dendrocogos pubesgens)

The downy woodpecker was common on the watershed, and was observed in approximately equal numbers in both treated and untreated areas.

Western Wood Pewee (Contopus sordidulus)

The western wood pewee was one of the most common birds on the watershed, and was present in much greater numbers in the treated area. On 16 July 1969, a famale was

found sitting on a nest approximately 15 ft high in a small aspen tree (6 inches in diameter) in the untreated area. Three young were seen in this nest 28 July and had left the nest by 11 August.

Olive-Sided tlycatcher (Nuttallornis Corealis)

All observations of olive-sided flycatchers were made in treated aspen areas of the watershed. One bird was seen 25 June 1966, one was sighted 27 August 1968, and two were seen 20 June 1969.

Tree Swallow (Iridoprocne bicolor)

Tree swallows ware common on the watershed, and were extremely numerous at the ponds and lakes in the vicinity. The nests of these birds, located in holes of aspen trees, were most noticable in the treated areas of the watershed. 45 The adults were feeding young in their nests each summer from approximately 15 June to 15 July, and in flight for at least a week afterwards. These birds were most often seen feeding in flight over treated and untreated meadows.

Purple Martin (Progne subis)

Purple martins were present only in the vicinity of ponds and lakes. A pair of these birds were feeding young in a nest in a hole of an aspen tree at Gates Lake 16 July 1968. There were two pairs feeding young,in nests at Gates Lake 10 July 1969, and an adult male and female were observed feeding young birds in flight 15 August 1969 at a pond located approximately 1 mi East of Sheep Creek Watershed.

Gray Jay {Cyanocitta cristata)

The gray jay was not sighted on Sheep Creek Water- shed, but was common in the vicinity of Gates Lake, approximately½ mi South of the watershed.

Steller•s Jay (Cyanocitta stelleri)

Steller•s jays were frequently seen in both treated and untreated areas of the watershed in early June and late August of each summer, but were seldom sighted in late June, July, and early August. One nest, located approximately 4 ft high in a bushy willow of an untreated meadow area, was found 4 June 1969 that contained 3 eggs. 46 Scrub Jay (Aphelocoma coerulescene)

Scrub jays were sighted only twice on the watershed: 27 July 1968 and 21 August 1969. Both sightings of these birds were in an untreated oak area at 8,400 ft, but they were fairly common in pinyon-juniper and oak areas of lower elevations northwest of the watershed.

Black-Billed Magpie (.e!.9.!!.pica)

Magpies were seldom sighted on the watershed. Three of these birds were seen in the treated aspen area 22 August 1968, one was seen in the untreated area 4 June 1969, two were seen in the treated area 25 August 1969, and four were sighted in the untreated area 26 September 1969.

Common Raven (Corvus c orax)

Ravens were frequently sighted flying over the watershed during both summers of the study. These birds were usually seen in groups of 2 - 4 and were seldom seen singly. Ravens were not seen on the ground or perched in trees except along roads at lower elevations where jackrabbits or squirrels had been killed.

Pi:nyon Jay (Gymnorhinus cyanocephala)

No pinyon jays were sighted on Sheep Creek Water- shed, but they were frequently seen at lower elevations northwest of the watershed. 47 Clark's Nutcracker (Nucifraga columbiana)

The clark's nutcracker was sighted three times on the watershed during the study. One bird was seen flying over the watershed on 12 August 1968 and on 22 August 1969, and one bird was seen on the ground along a road on 29 August 1968 •

Black-Capped Chickadee (Parus atricapillus)

The black-capped chickadee was one of the common birds on the watershed, and was seen in approximately equal numbers in both treated and untreated portions. On two occasions, 25 June 1968 and 17 June 1969, adults were observed entering small holes in dead aspen stumps carrying what appeared to be small insect food items. Both of these nest sights were in treated aspen areas of the watershed.

Dipper (Cinclus mexicanus)

One dipper was observed on 27 June 1968, about½ mi North of the watershed, gathering food from Gooseberry Creek and feeding at least one young in a nest located in a rock crevice near a bridge abutment. None of these birds were seen in 1969.

House 111ren (Troglodytes aedon)

The house wren was fairly common on the watershed, 48 and was seen in slightly greater numbers on the treated area. On 4 June 1969, a nest, containing 5 eggs, was found in a hollow rotting aspen log lying on the ground in the treated portion of the watershed. A pair of wrens were also observed feeding young in a nest, located in a hole in an aspen t~ee, approximately 12 ft above ground at Gates Lake on 10 July 1969.

Rock lllren (Salpinctes obsoletus)

One rock wren was seen 25 August 1969 in an untreated meadow at an elevation of 8,500 ft.

Robin (Turdus migratorius)

Robins were one of the most common birds on Sheep Creek Watershed during May, June, and early July, but were less commoR in late July, August, and September. These birds were seen in greater numbers in the untreated portion of the watarsh~d, and several nests were found in both treated and untrea~ed areas during both summers of the study. A pair raised. 3 young in a nest, located approximately 6 ft high in a Colorado blue spruce tree, at Gooseberry Ranger Station in 19~i~ Th~se young bird~ could fly by 20 June 1968. Two· young were raised the following.year in a nest, in a different tree of the same species, at near the same location, but these young could fly by 15 June 1969. 49 Hermit Thrush (Hylocichla guttata)

One hermit thrush was seen on each of two occasions, 18 June 1968 and 20 June 1969, in the untreated aspen area of the watershed.

Swainson•s Thrush (Hylocichla uslulate)

The swainson 1 s thrush was not common on Sheep Creek Watershed, and was not sighted at all on the treated portion. These birds were most often seen in dense stands of young aspen trees or thickets of willows and birch near sources of water~ lllouRtain Bluebird (Sialia currucoides)

Mountain bluebirds were not common on the watershed, but mere seen most often in dry meadows of both treated and untreated areas that contained scattered brush, trees, and· rocks~

Loggerhead Shrike (Lanius ludovicianus)

One shrike was seen 28 August 1968 perched in an oak bush in the treated portion of the watershed at an elevation of 8,100 ft~ No other sighting of these birds was made on the watershed or in the general vicinity. 50 Warbling Vireo (Vireo gilvus)

The warbling vireo was another uncommon bird on-· Sheep Creek Watershed and was not seen in the treated area. These birds were most often seen in willow and birch thickets or in the tops of mature aspen trees.

Vallow Warbler (pandroica petechia)

Yellow warblers were seldom seen on the watershed, and ware not seen in the treated area. On 25 June 1968, a nest, containing four eggs, was found approximately 1 ft high in a snowberry bush. Three young birds that could fly poorly were seen with tha adult female on 18 July 1968"'in the general vicinity of the nest. Immature birds mare also seen in willow and birch thickets along Gooseberry Creek just North of the watershed late in July of both 1968 and 1969.

Aud~bon•s Warbler (Dandroica auduboni)

Audubon's warbler was uncommon on the watershed, and was not seen in the treated area. These birds were most often seen during the month of June in the tops of mat~re aspen treas, and were seldom seen during July or August.

MacGillivray 1 s Warbler (pporornis tolmiei)

11: ,. MacGillivray•s warbler was not common on the w,ter- shad, and was sighted only on one occasion in the treated 51 area. These birds were most often observed in June and July in willow and birch thickets near sources of water. A few flocks of these warblers, up to 13 birds, were seen in untreated aspen areas in late, August of both summers.

Western Tanager (Piranga ludoviciana)

Western tanagers were seldom seen on Sheep Creek Watershed. These birds were seen only twice in the treated area and on four different occasions in the untreated area.

Black-Headed Grosbeak (Pheucticus melanocephalus)

An adult male and female black-headed grosbeak was sighted in a dense stand of untreated aspen trees on 4 June 1969 and an adult male was seen in the same area 2 July 1969. No other sightings of these birds were made.

Evening Grosbeak (Hesperiphona vespertina)

The evening grosbeak was seldom seen on the water• shed in June and July, but was seen in flocks of up to approximately 20 birds in both treated and untreated areas in August of both summers.

Lazuli Bunting (Passerina amoena)

Lazuli buntings were uncommon on the watershed, and were not seen in the untreated area. Small flocks of these birds (up to 8 birds) were seen in late August of each 52 summer. A nest, with three young, was found located 2 ft high in a dead willow of the treated area of the watershed on 8 July 1969. These young birds had left the nest by 20 July 1969.

Indigo Bunting (Passerina cyanea)

Only one indigo bunting was seen during this study; an adult male was sighted in a flock of lazuli buntings on 22 August 1968.

Caasin's finch (Carpodacus cassinii)

The casein's finch was not common on the watershed, and was seen more often in the untreated portion.

Pine Siskin (Spinus 9inus)

The pine siskin was one of the common birds of the watershed, and was seen in slightly greater numbers in the treated area. These birds nested high in a Colorado blue spruce at Gooseberry Ranger Station during both summers of the study~ The young birds could fly by 28 June 1968, and by 22 June 1969. A nest, containing four eggs, was found located approximately 6 ft high in a partially dead oak push of the treated area on 8 July 1969. On 20 July, the last of the four eggs hatched, and on 30 July, the young had left the nest, but could not fly well. 53 American Goldfinch (Spinus tristis)

The American goldfinch was not sighted on the water• shed, but one bird was seen on each of three occasions along tha road to Sheep Creek Watershed in the vicinity of rarnsworth Creek.

Green-Tailed Towhee (Chlorura chlorura)

The green-tailed towhee was uncommon on the watershed, and was sighted only on one occasion in the treated area. These birds were seen more frequently in untreated oak-areas of the watershed.

Gray-Headed Junco ( Junco caniceps)

The gray-headed junco was one of the most coMmon birds on the watershed, and was consistently seen in greater numbers in the untreated portion. Adults were observed feeding young that could fly poorly by 18 June 1968 and by 12 June 1969. Ona nest, containing two egQs, was found on the ground at the base of a small aspen tree (3 inches in diameter) in the treated area on 8 July 1969. Ona egg hatched 10 July and the other hatched 11 July, but the nest had been destroyed 16 July 1969.

Whita•Crowned Sparrow (Z0n0trichie laucoehrys) The white-crowned sparrow was not numerous on the watershed. This bird was seen more frequently in the un- 54 treated portion. A nest, containing three eggs, was found 10 June 1969 located at the base of two small (3 inches in diameter) close growing aspen trees in the untreated area. Three young were in this nest 15 June and had left the area by 2 July. On 25 June 1968, a nest, containing two young, was found on the ground in a stand of young aspen of the untreated area. These young birds had left the nest by 2 July 1968. fox-Sparrow (Passarella iliaca)

The fox sparrow was one of the common birds on ·Sheep Creek Watershed, and was seen in slightly greater numbers in the untreated portion. One nest, with four eggs, was found 4 June 1969 located approximately 2 ft high in a willow near Gooseberry Creek.

Lincoln's Sparrow (roelospiza lirfolnii)

Lincoln's sparrow was one of the most common birds of the watershed, and was generally seen in greater numbers in the treated portion. On 10 June 1968, a nest, containing four eggs, was found on the ground in the grass of the treated aspen area. Three young, that could fly poorly, were in the general vicinity of this nest 28 June 1968. Young Lin- 1 coln's sparrows were out of the nest and could fly by 18 June 1969. 55 Small aammals

Populations

The small mammal population estimates on the aspen trapping grids for the different trapping periods of 1968 and 1969 are summarized in figure 8 and Tables 12 and 13. In all trapping periods, except July in both 1968 aAd 1969, the estimate of the total small mammal population on the untreated grid was slightly higher than on the treated~ Estimates of the small mammal populations showed greater differences between the treated and untreated meadows than were evident between the treated and untreated aspen plots (Table 14). The estimate of the total small mammal population on the treated meadow grid was 64% lower than on the untreated grid during the 1968 trapping period, and was I 62% lower in 19690

Species

Vagrant Shrew (Sorax vagrans)

One vagrant shrew was caught in a museum special trap 18 July 1968 near Gooseberry Creek,½ mile southeast of Sheep Creek Watershed. No other shrews were observed or captured on or in the vicinity of the watershed.

Little Brown royotis (fflyotis lucifugus)

The little brown myotis used the attic of the Goose- 56 70 Control 60 ■ Treated ■ 50

June July Aug. June July Aug. 1968 1969

Fig. a. Small mammal population estimates on the ·aspen trapping grids (300 x 300 ft). berry Ranger Station as a daytime roost. No other bats were identified from the general area.

Rock Squirrel (Spermophilus variegatus)

Rock squirrels were fairly common at lower elevations northwest of Sheep Creek Watershed, but none were seen on the watershed. One of these squirrels was seen in the vicinity of Gooseberry Ranger Station 27 August 1968.

Uintah Ground Squirrel (Spermophilus armatus)

The Uintah ground squirrel was n~merous around all of the buildings in the vicinity of Gooseberry Ranger Station, and was common in some meadows approximately½ mi East of Table 12. Small mammalpopulation estimatesa on the aspen t1apping grids {300 x 300 ft) in 1968 (Eut. l'lin. = Eutamias minimus,~Per. lllan. = Peromyscus maniculetus, ~ic. Lon.• l'licrotus longiceudls, and Zap. Pri. = Zapus princeps).

Eut. l'lin. Per. Plan. Mic. Lon. Zap. Pri.

J'llale female l'lale female J'llale female l'lale female

b Trapping Period Grid Total Total Total Total Total

17 - 21 June Control 3.00 1.00 9.75 1.00 1.00 o.oo o.oo o.oo 4.00 10.05 1.00 o.oo 14.64 Treated o.oo o.oo 2.00 o.oo 4.67 1.00 o.oo o.oo o.oo 2.00 7.65 o.oo 9.16 9 - 13 July Control 13.81 7.53 14.68 10.90 17.67 18.84 2.00 2.00 17.28 19.98 26.57 4.00 62.83 Treated 1.00 o.oo 4.38 4.05 30.83 40.88 o.oo o.oo 1.00 1.11 61.94 o.oo 67.31 19 - 23 August Control 5.14 2.00 7.44 6.95 16.00 21.os o.oo 3.00 9.80 16.42 35.33 3.oo 61.12 Treated 1.00 2.00 4.00 6.33 36.42 31.83 1.00 o.oo 3.oo 11.93 46.97 1.00 59.28 Summer0 Control 15.36 9.01 25.81 15.03 20.07 23.51 2.00 3.25 22.01 31.42 34.36 7.63 74.39 Treated 3.oo 2.00 10.21 0.1s 39.58 49.42 1.00 o.oo 4.87 14.32 67.49 1 .2s 66.41

arrom Hayne•s {1949) modified ratio method {see methcds section) bAll totals are population estimates at the end of each study period end are not the sums of the various species...... ,UT cThe data from the three trapping periods were pooled and a population estimate was calculated. Table 13. Small mammalpopulation estimates 8 on the aspen trapping grids (300 x 300 ft) in 1969 (Eut. IYlin. = Eutamias minimus, Per. ~an.• Peromyscus maniculatus, ~ic. Lon.• ~icrotus longicauws, and Zap. Pri. = Zopus princeps}.

Eut. IYlin. Per. ltlan. !'lie. Lon. Zap. Pri.

lllale remale Male female l'lale remale l'lale female

Trapping Period Grid Total Total Total Total Total b

18 - 25 June Control 8.25 2.00 3.75 1.00 6.92 3.47 5.14 o.oo 12.90 4.64 10.52 s.14 26.57 Treated 1.00 o.oo o.oo o.oo ?.77 4.09 1.00 1.00 1.00 o.oo 9.24 2.00 . 13.38 16 - 23 July Control 3.33 3.04 4.67 2.73 s.61 5.59 2.25 1.00 6.29 s.oo 11.29 2.so 24.85 Treated 2.00 1.00 3.17 1.00 12.61 9.36 1.00 1.00 3.oo s.3a 19.58 2.00 27.46 13 - 20 August Control 1.00 1.00 3.69 4.63 7.51 s.oo 4.67 1.00 2.00 7.37 10.91 s.oo 24.37 Treated 1.00 o.oo 2.00 1.00 9.43 10.83 o.oo o.oo 1.00 3.oo 16.58 o.oo 19.92 Summerc Control 10.78 3.82 s.76 4.82 12.78 9.42 9.00 2.25 12.66 11.55 21.13 13.75 44.69 Treated 5.14 1.00 3.92 2.00 22.29 19.40 2.25 2.00 6.67 7.44 35.29 3.66 39.34

arrom Hayne's (1949) modified ratio method (see methods section) bAll totals.are population estimates at the end of each study period and are not the StJmsof the various species. (J1 crhe data from the three trapping periods were pooled and a population estimate was calculatedo CD 59

Tabla 14, Small mammalpopulation astimates 8 on the meadowtrapping grids (150 x 150 ft).

29 July• 2 Aug. 1968 28 July - 4 Aug. 1969

Spaciaa Control Treated Control Treated

Euta111,minim,us o.o o.o o.o o.o ParpmvacusMoiculatua s.21 3.14 3.93 2.2s Micratuelongicaudua 11.46 6,18 8,23 4,89 z,ew•arincaas 8,21 1,27 12.39 2.12 Totalb 26,78 9,61 23,56 a.94

8 from Hayna•s (1949) modified ratio method bAll totals are population estimates of the grid at the and of each study period and are not sums of the various apeciaa.

Sheep Creek Watershed. This squirrel was not seen on the treated' portion of the watershed, and was sighted only twice in meadows of the untreated area. These squirrels were not seen above ground after 20 August, both 1968 and 1969, and appeared to have been active above ground for some time by 3 may 1969,

Gold-Mantled Squirrel (Spe£moehilus lataralis)

The gold-mantled squirrel was often seen along the road North of Sheep Creek watershed between elevations of 6,000 and a,ooo ft in pinyon•juniper and oak brush habitats. These squirrels were seen in no other areas during this study, 60 Least Chipmunk (Eutamias minimus)

The least chipmunk was common in aspen and oak brush habitats of the watershed. Chipmunk population estimates on the treated aspen trapping grid averaged 84% lower than the untreated grid in 1968, and averaged 66% lower than the untreated grid in 1969 (figure 9). The population estimates of chipmunks on the untreated aspen trapping grid averaged 38% lower in 1969 than in 1968 and 27% lower in 1969 than in 1968 on the treated grid.

Red Squirrel (Tamiasciurus hudsonicus)

One juvenile red squirrel was captured on the untreated aspen trapping grid 28 August 1968, and one adult was seen in a Colorado blue spruce tree at Gooseberry Ranger Station 5 June 1969.

Northern flying Squirrel (Glaucomys sabrinus)

One flying squirrel was captured in the untreated aspen area in June 1967 by forest Service personnel. No flying squirrels were captured or sighted during this study.

Northern Pocket Gopher (Thomomys talpoides)

Pocket gophers were common on all areas of the watershed. Table 15 summarizes the average number of pocket gopher mounds and earth plugs per 50 x 450 ft transect. In 61

Control ■ 60 Treated ■ 50

June July Aug. June July Aug. 1968 1969 fig. 9. Population estimates of Eutamias minimus on t~a aspen trapping grid• (300 x 300 ft). both 1~68 and 1969, the average numbers of mounds and earth plugs per transect were lower in the treated aspen area than in the untreated, but these differences were not significant. The number of pocket gopher mounds and earth plugs per transect in the treated meadow was significantly lower than in the untfaated meadow in both 1968 and 1969.

D"er Mouse (Peromvscus maniculatus)

Daer mice were common on all areas of the watershed. Population estimates of deer mice on the treated aspen trapping gr!d averaged 55% lower than on the untreated grid in 1968, and in 1969 population estimates on the treated grid were 50% lower than on the untreated (figure 10). Popula• tions on the untreated aspen grid averaged 65% lower in 62

Table 15. Average number of packer gopher (Thoma ■YB talpaidas) mounds and earth plugs per 50 x 450 f't transact.

Data Treatment Aspen l'laado111

28 Sept. 1968 Control 19.00 35.50 Treated 14.14 24.00*

27 Sept. 1969 Control 16. 75 31.50

Tr.sated 12.75 19.so*

*significant difference from tbe control at the 5%level

1969 than in 1968, while the populations on the treated aspen grid averaged 56% lower in 1969 than in 1968. The population estimates for the meadow trapping grids were 40% lower on the treated than the untreated in 1968 and 43% lower on the treated than the untreated in 1969. The untreated meadow grid population was 25% lower in 1969 than in 1968, and that of the treated grid was 28% lower in 1969 than in 1968.

Longtail Vole ~ ( IYlicrotus longicav{dus) I

The longtail vole was the most common rodent on all areas of the watershed. The population estimates on the aspen trapping grids averaged 47% higher on the treated than on the untreated in 1968 and 34% higher on the treated than on the untreated in 1969 (Figure 11). Populations on the untreated aspen grid averaged 46% lower in 1969 than in 1968, while on the treated grid, the populations averaged 56% low- 63

60 Control ■

50 Treated ■

June July Avg. June July Aug. 1968 1969 fig. 10. Population estimates of Peromyscus maniculatus on the aspen trapping grids (300 x 300 ft). er in 1969 than in 1968. The population estimate of longtail voles on the meadow trapping grids was 58% lower on the treated than on the untreated in 1968, and was 41% lower on The treated than on the untreated in 1969. The population on the untreated meadow grid was 28% lower in 1969 than in 1968, and on the treated grid the population was 21% lower in 1969 than in 1968.

Western Jumping Mouse (l_~pus princeps)

The western jumping mouse was present in all areas of the watershed. On the aspen trapping grids, the population estimates averaged 86% lower on the treated than on the untreated in 1968, and in 1969 population estimates averaged 72% lower on the treated than the untreated grid (Fig- 64

60 Control ■ 50 Treated • 40

June July Aug. June July Aug. 1968 1969 fig, 11. PQpulation estimates of Microtus longicaudus on the espen tr~pping grids (300 x 300 ft). ure 12). Populations averaged 44% higher in 1969 than in 1968 Qnthe untreated aspen grid, while on the treated grid, populations averag~d 71% higher in 1969 than in 1968, The population estimate of jumping mice on the treated meadow grid was 85% lower than the untreated grid in 1968, and was 83% lower than the untreated in 1969. The population on the untreated meadow grid was 18% higher in 1969 than in 1968, while on the treated grid, the population was 51% higher in 1969 than in 1968•

Large Mammals

Species

Black Bear (Ursys americanus) The black bear was not seen during this study, One 65

60 Control ■

so Treated ■

June July Aug. June July Aug. 1968 1969

Fig. 12. Population estimates of Zapus princeps on the aspen trapping grids (300 x 300 ft). bear was sighted during herbicide treatment operations in June of 1965 in the southeast portion of the watershed, and bear tracks were found by Forest Service personnel in the same area during the summer of 1966. Several trees were found in both treated and untreated areas of the watershed that had previously been marred by bears.

Shorttail Weasel (mustela erminea)

The shorttail weasel was present in all areas of the watershed. During the summer of 1968, two shorttail weasels were captured in the live traps on the small mammal trapping grid of the untreated aspen area, and three were captured on the treated grid. In 1969, one was captured on the untreated aspen grid, two were captured on the treated aspen grid, and one was taken on the treated meadow grid. 66 Longtail Weasel (Muatelg frenata)

The longtail weasel was observed or captured in all areas of the watershed. Two were captured on the trapping grid of the untreated aspen area in 1968, and one was captured on each of the treated and untreated aspen grids in 1969~

Sadger (Taxidea taxus)

One badger was seen 28 August 1968 in an untreated aspen area at B,200 ft elevation.

Coyote (Canis latrans)

No coyotes .were seen during this study, but tracks ware seen both summers at lower elevations northeast of Sheep Creek Watershed. Tracks were also seen in the snow on 3 rebruary 1969 in the same general area.

Bobcat (.Lr.!.!J.lryfus)

Bobcats were not seen during this study and the only evidence of their presence in the area was tracks seen approximately l mi northeast of the watershed in the snow 3 Febru- ary 1969.

Yallow6elly Marmot (Marmctafleyiventris)

marmots were not common on the watershed, but ware 67 sighted several times in treated and untreated meadows and along the road to Sheep Creek Watershed.

Beaver (Caster canadensis}

Beaver were not present on the watershed, but were seen at Gates Lake in both 1968 and 1969.

Porcupine (Erethizon dorsatum)

Porcupines were not common on the watershed,"but were seen several times during both summers in treated and untreated aspen and oak brush· areas.

Snowshoe Hare (Lepus americanus)

One snowshoe hare was seen on 26 August 1968 in untreated aspen at 8,200 ft elevation.

Blacktail jackrabbit (Leous californicus)

One jackrabbit was seen on each of three occasions,

8 and ?1. ~ugust 1968 and 8 July 1969. All sightings were along a road apprQximately ½ mi East of Sheep Creek Water- shed in a nixed oak brush and aspen area at B,100 ft elevation.

Cottontail (Svlvilagus sp.)

One cottontail was seen 20 July 1969 in the same 68 general area that the jackrabbits had been sighted. This rabbit could not be positively identified. mule Deer (Odocoileus hemionus)

Deer were seen almost daily during the study and were seen in every area of the watershed. Estimates of· summer animal-days use per acre by deer were significantly lower in the treated portion of the watershed than in the untreated area both summers of the study (Table 16). The a~imal-days use per acre by deer was slightly higher in 1969 than in 1968 in both treated and untreated areas of ' the watershed.

Elk (Cervus canadensis)

Elk were seen on the watershed in May, early-Jone, and·in September of each year and were seen most often in the southeast portion. Estimates of the summer animal-days use by elk were higher in the treated portion of the watershed than in the untreated in both 1968 and 1969, but these differences were not significant at the 5% level (Table 16). ' The watershed use by elk was slightly higher in 1969 than in 1968 in both treated and untreated areas. 69

Tabla 16, Estimates af the summeranimal-daya use par acre by deer and elk,

Data Treatment Daer Elk

28 Sept, 1968 Control 1.2 0.2 Treated o,s* 0,3

27 Sept, 1969 Control 1,4 0,3 Treated 0,7* o.s

*Significant difference from the control at the 5% level 70

DISCUSSION

Soil Arthropods

The coefficients of similarity between soil arthropod populations on the aspen study plots indicate that the populations in the treated and untreated areas were more alike than different both years with respect to species composition and numbers of individuals (Table 17). There was also very little difference between soil arthropod populations in 1968 end those in 1969 on both treated and untreated aspen study plots. r1uctuations in soil arthropod populations were evident from month to month in both treated and untreated areas during 1968 and 1969. These population changes seem insignificant since they were generally cha~ges in numbers of individuals, not changes in general species composition. Although the soil environment, to a depth of 3 inches, seems to have been affected little by the herbicide treatments, the coefficients of similarity indicate that the soil arthropod populations are more stable from month to month and from year to year in the treated aspen area than in the untreated. The soil arthropod populations on the treated and untreated meadow study plots were very similar both years of the study, even though the average number per sample was 71

Tabla 17. Percent similarity between soil arthropod populations in the aspen study plots.

June Julx August Summet8 Comparison 1968 1969 1968 1969 1968 1969 1968 1969

Control vs. Treated 58 45 '75 80 51 64 61 68

1968 1969 Control Traatad Control Treated

June vs. July 27 39 25 69

June vs. Aug. 25 62 60 87 July vs. Aug. 36 47 51 66

June Julx August Summer C T C T C T C T

1968 vs. 1969 24 79 70 79 57 63 53 77

8 Tha data collected each month••• pooled and the coefficient of similarity is basically an average of the three months. always greater from the treated area. The coefficients of similarity for soil arthropods on the meadow study plots (Table 18) indicate little difference between populations in the treated and untreated plots, and very little population fluctuation in either area from month to month or from year to year. The soil arthropod population study results from the aspen plots agree with the results of Davis {1965). Although the soil arthropod numbers w,re variable and showed fluctuations each summar, little difference was evident be- 72

Table 18. Percent similarity between soil arthropod populations in the meadow study plots.

June July August Summer Comparison 1968 1969 1968 1969 1968 1969 1968 1969

Control vs. Treated 69 81 63 87 84 88 70 86

1968 1969 Control Treated Control Treated

June vs. July 59 43 57 56

June vs. Aug. 69 63 63 67

July vs. Aug. 85 65 92 81

June July August Summer C T C T C T C T

1968 vs. 1969 71 74 66 95 61 68 65 84

aThe data collected each month was pooled and the coefficient of similarity is basically an average of the three months. tween populations on treated and untreated areas. Even though the species composition of soil arthropods in each meadow area was nearly constant throughout this study, the average number of individuals per sample was consistently higher from the treated meadow plots, and may indicate a slight increase in these populations as a result of the herbicide treatments. 73 foliage Insects

The coefficients of similarity between the foliage insects in the aspen study plots indicate differences between these populations in the treated and untreated areas with respect to numbers of individuals and species composi• tion (Table 19). The foliage insect populations on both treated and untreated aspen plots showed marked fluctuations from month to month and were different each year. Robin.sen (1959) and Maxwell and Harwood (1969) reported increases in insect populations as a result of herbicide applications on bread bean plants, but the results cf my study indicate the insect species composition was slightly different in each area, and that the population numbers were significantly lower on the treated aspen study plots. The foliage insect populations on the meadow study plots showed marked differences in numbers of individuals, and slight differences in species composition between the treated and untreated plots (Tabla 20). There was little difference in foliage insect populations from year to year in either the treated or the untreated meadow study plots, but there were slight fluctuations in each area from month to month during each summer. The results of these insect studies in meadow areas are in agreement with the results of Robinson (1959) and maxwell and Harwood (1960); a marked increase in foliage insect numbers was evident as a result of the vegetation changes brought about by applications of herbicides. 74

Table 19. Percent similarity between foliage indicator insect populations on aspen study plats.

June July August Summpr Comparison 1968 1969 1968 1969 1968 1969 1968 1969

Control vs. Treated 38 26 58 57 57 39 54 48

1968 1969 Control Treated Control Treated

June vs. July 29 33 37 54

June vs. Aug. 33 a 43 43

July va. Aug. 61 39 51 41

Jyne Julv August Summar C T C T C T C T

1968 vs. 1968 27 27 74 59 52 35 52 42

8 The data collected each month was pooled and the coefficient of similarity is basically an average of the three months.

Even though the grass species, composition, and cover are nearly the same in treated aspen and treated meadow areas, the insects, notably leafhoppers and some. fliei, decreased in the aspen areas but increased in the meadow areas. One of the factors that could have limited insect numbers in treated aspen areas more than in treated meadow areas, is that some insect feeding birds may be attracted to aspen areas because of the increased visibility, mobility, and perches offered by the dead or defoliated trees and shrubs. These same birds may also avoid treated 75

Tabla 20, Percent similarity batwaan foliage indicator insect populations on meadowstudy plots,

June July August Summer• Comparison 1968 1969 1968 1969 1968 1969 1968 1969

Conti-al vs, Treated 45 37 59 63 40 49 49 48

1968 1969 Control Ti-sated Conti-al Treated

June vs, July 37 48 51 52

June vs, Aug, 49 52 34 50

July vs, Aug, 65 81 63 71

June July August Su11mer C T C T C T C T

1968 vs. 1969 74 85 75 72 61 83 70 79

8 The data collected each month was poalad and the coefficient of similarity is basically an average of the three months, meadows because of the habitat changes brought about by the elimination of the forbs and shrubs formerly used as perches and food sources,

Aquatic Invertebrates

Even though the analysis of water from rernsworth Creek (untreated) and Sheep Creek (treated) showed little chemical difference between the two creeks, some of the differences in animal population could be attributed to the foll~wing factors: (1) these creeks are located in different 76 watersheds approximately l mi apart, (2) each creek has a different water source, and (3) there may be differences in substratum in each creek. The coefficients of similarities for aquatic animal populations (Table 21) indicate some differences in species composition and numbers of individuals between these populations in the treated and untreated creeks, except during the month of June 1968. The samples taken in June 1968 were taken in treated and untreated portions of the same creek lass than¼ mi apart, and the high coefficient of similarity between these areas may indicate that herbicide treatment of streams actually has little affect on the aquatic animal populations, as has bean reported by Smith and Isom (1967). The number of aquatic animals par sample over the complete study averaged nearly the same in both treated (124) end untreated (123) creeks and may indicate that, although the species composition varies due to different life cycles and times of emergence, the numbers of aquatic animals per ft 2 of stream bottom surface at a particular time was affected little by the herbicide treatments~ Even though the two creaks were sampled the second and third years after treatment, it is suggested that had the samples been taken immediately before and after the h~rb- icide applications the results would have been basically the same. Hansen (1952) and Smith and Isom (1967) found little or no effect on aquatic insect populations immediately after herbicide treatments. There would also be little danger to 77

Table 21, Percent similarity between aquatic invertebrate populations in rarnsworth Creek (Control) end Sheep Creek (Treated),

June July August Summer8 Comparison 1968 1969 1968 1969 1968 1969 1968 1969

Control vs, Treated 76 34 49 58 49 41 59 45

1968 1969 Control Treated Control Treated

June vs, July 32 49 59 57

June vs, Aug, 54 35 60 62

July vs, Aug, 59 47 64 68

June July August Summer C T C T C T C T

1968 vs. 1969 1 20 44 52 24 58 23 39

8 The data collected each month was pooled and the coefficient of similarity is basically an average of the three months. plants and animals, including man, downstream from treated areas because of the low toxicity, dilution, and breakdown of the auxin herbicides used.

Birds

There were 55 species of birds sighted on or in the vicini~y of Sheep Creek Watershed, but only 12 species accounted for apprcximately 90% of the bird pop~lation on the watershed. CoeffiCi$nts of similarity {Table 22) indicate a degree of difference between the bird populations on 78

Table 22, Percent similarity between bird populations on the transects.

JUDI ~ulx Augu1t Seetember Summer8 Comparison 1968 1969 1968 1969 1968 1969 1968 1969 1968 1969

Control vs, Treated 32 72 40 58 38 50 81 50 46 58

1268 1969 Control Treated Control Treated

June vs, July 44 41 66 76 June vs, Aug. 40 41 39 78

June vs. Sept, 62 13 39 57

July vs. Aug, 65 73 45 78

July vs. Sept. 16 8 60 55

Aug, VB, Sept, 21 26 24 68

Juo1 d!i!lX August Seetember Summer C T C T C T C T C T

1968 vs, 1969 47 46 47 76 88 62 70 39 60 60

arhe data collected each month was pooled and the coefficient of similarity is basically an average of the four months, treated and untreated transects with population fluctuations month to month during each summer in both areas. The coefficients of similarity also show a degree of similarity 1r the populations from year to year in both treated and untreated areas. During each summer, the bird populations showed nearly the same pattern of increase or decrease in the treated or untreated areas (rigure 7), This pattern seems to indicate that more birds used the untreated area during their 79 nesting period (June), but moved to the treated portion upon completion of nesting activities. Another shift was evident just before the fall migration when the bird population was approximately equal in the treated and untreat-.ed areas. The untreated portion undoubtedly provides a greater number of better protected nesting sites for most birds than the treated area, and after the young have fledged, the birds may be attracted to the increased availability of food in the treated areas. Grass seeds are very abundant in the treated areas in middle and late summer, and even though the numbers of insects are lower in the treated aspen portions of the watershed, they may be more available to birds because of the elimination of the shrubs and herbs in the understory. The habits and habitat requirements of the individual species were the factors that determined if a particular species increased or decreased in numbers in the treated area of the watershed. Hole nesting birds, such as the red-shafted flicker and the tree swallow, were observed more often at nests and feeding in the treated areas than in the untreated. This was most likely due to the increased availability of nesting sites offered in the greater numbers of dead aspen trees of the treated area. The western wood pewee perches preferably in dead trees at the edges of forest openings, and captures insects from the general vicinity of the perch. As a result of the herbicide treatments, more dead trees and more forest openings were produced which created a habitat favorable to the western wood pewee. The increase in sightings of the lincoln sparrow in the treated area over 80 the untreated may be an example of an increase in grassy nesting sites along with an increase in grass seeds and availability of insects as a food supply. The decrease in use of the treated areas by the ruffed grouse indicates that the grouse prefer a habitat which includes broadleaf herbs and shrubs in the understory and a forest canopy in the overstory. Sharp (1963) reported increased use as feeding areas by ruffed grouse broods on cut over forest plots with good broadleef herb and brush cover, but as succession proceeded back to the forest type with sparse herb and brush cover in the understory, the brood use by grouse decreased on the study plots. He also found that the adult grouse seemed to have been little affected by the vegetation manipulation. The results of my study indicate a general avoidance by grouse of areas with a dense tall grass understory lacking broadleaf herbs and shrubs.

mammals

Coefficients of similarity for small mammal populations on the aspen trapping grids indicate a degree of similarity between the populations on the treated and untreated grids (Table 23). There were greater population fluctuations from month to month in 1968 than in 1969 in both treated and untreated areas, and there was a degree of similarity between populations during 1968 and 1969 in both treated and untreated areas. The small mammal species composition on the aspen trapping grids was similar on both 81

Table 23. Percent similarity between smell mammalpopulations on aspen trapping grids.

June July August Summer• 1968 1969 1968 1969 1968 1969 1968 1969

Control vs. Treated 24 52 51 78 80 65 59 69

1968 1969 Control Treated Control Treated

June vs. July 34 25 82 57

June vs. Aug. 28 25 79 61

July vs. Aug. 68 78 82 82

June Julv August Summer C T C T C T C T

1968 vs. 1969 49 73 57 55 54 53 54 56

8The data collected each month was pooled end the coefficient of similarity is basically an average of the three months. treated and untreated grids, and the total small mammal population on each grid was very nearly the same. In 1968, the population estimates on the treated grid averaged 3 animals lower than the untreated estimates, and in 1969 the estimates on the treated grid averaged 6 animals lower than the untreated estimates. The differences between the small mammal populations on the treated and untreated grids were due to the changes in numbars of individuals of each species. In the total population on the treated gridt the reductioh in numbers of chipmunks, dear mice, and jumping mica was 82 balanced by the increase in numbers of longtail voles. This seems to indicate that the carrying capacity has been changed little as a result of the herbicide treatments, but the habitat has been altered to favor one small mammal over the others. The great differences between small mammal population estimates from the treated and untreated meadow grids indicate a reduction in the carrying capacity for all small mammals on the treated meadows, and thus, a significant change in the habitat as a result of herbicide treatments. The moat important reason for the marked reduction of all small mammals on the treated meadow may be the elimination of the broadleaf plants that produce the preferred food supply of these rodents. Johnson (1964) reported that deer mice, least chipmunks, and voles, ate more grass seeds in areas treated with 2,4-D, but preferred seeds and plant parts of forbs, where they were available. All of the small mammals trapped in this study on the meadow grids seemed to be closely associated with the broadleaf plants of the meadows. The results of this study generally agree with the results reported by Johnson and Hansen (1969) on studies of rodent populations on 2,4-D treated shrub-grass range in

Col.orado in two aspects 1 ( 1) numbers of least chipmunks were reduced and (2) the vole numbers increased in the treated aspen area. Johnson and Hansen (1959) found the deer mouse population little affected by the 2,4-0 treatment, while my data shows a marked reduction of deer mice on the treated aspen grid and a slight decrease on the treated meadow grid. 83 Population reductions of least chipmunks and deer mice on the treated aspen grid seem primarily due to changes in availability of food and cover, while those of the longtail vole were probably due to cover changes, as was found by Johnson and Hansen (1969). The effects on the longtail vole population were different in the two treated areass the numbers increased on the aspen grid, but decreased on the meadow grid. The reason for this difference seems to be the presence of either standing or fallen, dead or defoliated trees and shrubs which may be important in the habitat that favors increased vole populations. No reports have been made on western jumping mouse populations in areas treated with herbicides, but my data show that in treated aspen and meadow areas the populations were markedly reduced. The reduction seems primarily due to the unavailability of cover and food items from forbs. The results of this study, reduction of the pocket gopher populations on treated aspen and meadow areas, generally agree with what has bean reported by Keith .!i J!.!• (1959), Hansen and Ward (1966), Tietjen.!!.!.!• (1967), and Johnson and Hansen (1969). All of the above studies indicated that the reduction was due to availability of food, but with the reestablishment of the vegetation on the treated plots the pocket gopher populations returned to before treatment levels. My data indicate that pocket gopher populations ~ere higher in dry meadow areas than in aspen areas, and that 84 the population reductions after treatment were greater in the treated meadow than they were in the treated aspen. The pocket gopher activity, as indicated by counts of mounds and earth plugs, was 35% lower en the treated meadow than the untreated in 1968 and 37% lower in 1969, while activity was 25% lower on the treated aspen than the untreated in 1968 and 20% lower in 1969. The results of this study, with respect to deer and elk, were generally to be expected. Deer use of the treated watershed was significantly less than untreated, and elk use of the treated was slightly greater than the untreated. These results reflect the food preferences and habitat requirements of each animal. mueggler (1966) and Krefting and Hansen (1969) have shown that browse was increased after some controlled herbicide treatments, and that deer were attracted to treated areas. My results indicate that deer avoid areas in which all the broadleaf plants have been killed or defoliated by herbicide treatments. Elk may not have been attracted to treated areas since they had been extensively using an area in the southeast portion for several years before treatment, and this area accounted for approximately 75% of the elk pellet groups on the treated watershed in both 1968 and 1969. few records of the shorttail weasel in Utah have been published and Durrant (1952:417) indicates that this weasel may be uncommon throughout the state. On the Sheep Creek Watershed, I found the longtail weasel less abundant 85 than the shorttail weasel, judging from the number of captures, and took the latter more often on the treated portion of the watershed. The increase in numbers of the shorttail weasel on the treated aspen portion of the watershed may be due to high microtys population as a food source. The other large mammals present on the watershed ware sighted so seldom that they were of little consequence to this study. The interpretation of the effects of herbicide treatment on animal populations in the treated areas is a diffi- cult task. A degree of caution must be exercised in the interpretation of some of the data collected; the values of all aspects of multiple use of watersheds and the particular ecological community must be carefully considered before any recommendations or condemnations of vegetation manipulation can be made. A comparison of my data and results with those of Hayward {1945 and 1948) indicates that the aspen commqnity of the Sheep Creek Watershed is a transition community between the chaparral communities or lower elevations and the montane coniferous forest of higher elevations. There were six natural biotic communities on the watershed, and as a result of applications of herbicides, at least two new biotic communities were created: {1) treated aspen and {2) treated dry meadow communities. Although these two areas were very similar with respa~t to living plant species and composition, the animal residents of each area showed great differences~ These differences in ~nimal populations appear 86 to be due to the presence of dead or defoliated trees and shrubs in the treated aspen areas. much additional work needs to be completed to determine detailed ecological relationships, especially of the arthropods and the birds, before specific recommendations can be made as to the future uses of vegetation manipulation by herbicide treatments. With few exceptions, the animal populations have decreased significantly or remained near the same in the treated areas, with a trend toward a reduction in the number of species occupying these areas. Thus, un• treated aspen and meadow communities of the Sheep Creak Watershed seem to be generally more productive with respect to numbers of species and numbers of individuals. There may be some benefit to elk in treated areas since a slight increase in use of the treated area was evident, but other game species such as the deer and the ruffed grouse, tended to avoid the treated portions of the watershed. Therefore, because of the effects disturbed habitats have on the resi- dent animal populations, large scale application of herbicides on aspen and meadow communities are not recommended. Herbicide treatments limited to smaller localized areas may be very valuable to control certain undersirable plants, to help increase or decrease use by game animals and domestic stock or to help control some rodents such as pocket gophers when they are at high population levels. 87

SUMMARY

As a result of applications of 2,4-D (2,4-dichlor• ophenoxyacetic acid) and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid), the vegetation on approximately one-half (475 acres) of Sheep Creek Watershed, located 17 mi southeast of Salina, Sevier County, Utah, has been drastically changed from aspen, oak, and grass-forb•shrub communities to a grass type community. The animal populations, including arthro~ods,

/)~' ? birds, and mammals, were investigated on treated and untr~ated portions of the watershed during the summers of 1968 and 1969. The results of these investigations were compared and the indirect effects of herbicide treatments on the animal populations in the aspen and grass-forb community were· evaluated. There was no difference between soil arthropod populations on treated or untreated aspen study plots, but there were smaller population fluctuations on the treated study plots~ The species composition of the soil arthropods on meadow study plots were the same, but the average number of individuals per sample from the treated plots were significantly higher than from the untreated. Differences in species composition between treated and untreated plots in both aspen and meadow areas were evident and there was a significant decrease in foliage in- 88 sect populations on the treated aspen plots. There was, however, a significant increase in these populations on treated meadow plots. There were also marked fluctuations in foliage insect populations from month to month in both treated and untreated areas. Analysis of water from Farnsworth (control) and Sheep (treated) Creeks showed that there was little chemical difference between the two creeks. Some differences between aquatic animal populations from treated and untreated creeks were apparent, but these differences were primarily changes in species composition because of individual life cycles and times of emergence. Over the two year period, the number of aquatic animals per ft 2 of stream bottom surface was little affected by the herbicide treatments. Fifty-five species of birds ware seen on Sheep Creek Watershed er in the general vicinity, but only 12 species accounted for approximately 90% of the bird population on the transects. There were important population differences between the treated and untreated areas and definite patterns of population shifts from one area to the other. During both summers, more birds were present in the untreated area during the nesting period (June), but in July and August more birds were seen in the treated area. The populations were nearly the same in each area during September. It is suggested that these shifts in area of utilization by birds were due to a greater number of more favorable nesting sites in the untreated area in may and June, increased availability of 89 grass seed and insect food items in the treated area during July and August, and migrational activities in September. Some species such as the western wood pewee (Contopus sordidulus), Lincoln's sparrow (melospiza lincolnii), and red- shafted flicker (Colaptes cafer) were consistently observed in greater numbers on the treated area, while other species such as the grayheaded junco (Junco caniceps), the ruffed grouse (Bonasa umbellus), and Audubon's warbler (Dendroica auduboni) were seen in greater numbers in the untreated area. These differences reflect the habits and habitat preference of the individual species. There was no significant difference between total small mammal populations of the treated and untreated aspen areas, but the total small mammal population on the treated meadow area was significantly reduced. Least chipmunk (Eutamias minimus) population estimates on the treated aspen grid averaged 84% lower than the untreated in 1968 and 66% lower in 1969. Chipmunks were not captured on either grid located in dry meadow areas. Deer mouse (Peromyscus maniculatus) populations averaged 55% lower on the treated aspen grid than the untreated in 1968 and 50% lower in 1969, whereas deer mouse populations were 40% lower on the treated meadow grid in 1968 and 43% lower in 1969. The populations of longtail voles (microtus longicaudus) averaged 47% higher on the treated aspen grid than the untreated in 1968 and 34% higher ln 1969, while vole populations were 58% lower on the treated meadow grid in 1968 and 41% lower in 1969. Western 90 jumpi~g mouse (Zagu§ grinceps) papulation estimates averaged 86% lower on the treated aspen grid than the untreated in 1969 and 72% lower in 1969, whereas jumping mouse populations were 85% lower on the treated meadow grid in 1968 and 63% lower in 1969. The populations of chipmunks, deer mice, and voles were lower on all grids in 1969 than in 1968, but the populations of jumping mice were higher on all grids in 1969 than in 1968~ The differences between the small mammal populations on the treated and untreated grids were primarily due to changes in the availability of food and cover as a result of the elimination of the broadleaf trees, shrubs, and forbs by the herbicide treatments. Thus, the untreated aspen habitat was more favorable to chipmunks and deer mice, but the treated was more favorable to longtail voles, while the untreated meadow was more favorable to western jumping mice end pocket gophers (Thomomys tal,c,oides), but the treated was favorable to no small mammals. During both summers, the pocket gopher activity was slightly lower in the treated aspen area than the untreated, and significantly lower in the treated meadow than the untreated. The reduction of pocket gopher activity on the treated portions of the watershed was due to the elimination of the broadleaf forbs as a result of herbicide treatments. Deer (Opocoileus hemionus) use in the treated area was si;nificantly lower than the untreated during both sum• mers studied, whereas elk (Carvus canadensis) use in the treated area was slightly higher than the untreated during 91 these summers. Daer seemed to avoid areas in which the broadleef plants have been eliminated, qut elk may have shown some preference for these areas. The shorttail weasel (OOustpla 1rmioea) was captured or observed more often in the treated aapan portion of the watershad. The increase in shorttail weasels in the treated araa was probably due tc the increased vole population as a food source and the elimination of the shrub and forbs in the understory. Other larger mammals present on the watershed were the longtail weasel (f!lystala !rpnata), yallowbelly marmot (mermote flayiventris), and porcupine (E:rethizon dor• satgm), but they were captured or sighted so seldom that they wera of little consequence to this study. Tha animal populations on the Sheep Creek Watershed indicate that at least two new biotic communities were created 8$ a result of herbicide treatments: (1) treated as~en -dd (2) treated dry meadow communities. These·communities, with few exceptions, tended to support fewer species of animals and fewer individuals then untreated commun• ities. There may be some benefit to elk in treated areas, ' but the other game species, deer and ruffed grouse, tended to avoid treated portions of the watershed, Therefore, large scale herbicide applications on aspen and dry meadow commun• itiae are not recommended. Herbicide treatments, limited to small localized areas, may be valuable to control certain un- desirable plante, tb help increase or decrease use by game animals end domestic stockt or to help control some rodents such as pocket gophars, when their population levels are high. 92

LITERATURECITED

Adams, J. 8~ and M. E~ Drew. 1965. Grain aphids in New Brunswick. III Aphid populations in herbicide

treated oat fields. Can. J~ Zool~, 431789-794. Antoine, o. 1965~ Les antiparasitaires et las animaux domestiques, las abeillas at la vie sauvauge. Parasitica (Gembloux), 22:107-116. Ashley, R~ r~ 1968. The distribution of overwintering arthropods in a sheep pasture in Utah County, Utah. Unpublished master's Thesis, Brigham Young University, Provo, Utah. 19p. Audus, L~ J. 1964. Herbicide behaviour in the soil • .!!! The physiology and biochemistry of herbicides. Academic Press, London-New York~ 555p~ Bollen, w. B~ 1961. Interactions between pesticides and soil microorganisms. Ann. Rev. Microbiol., 15169-93. Colas, r. H. 1965. The effects of big game and cattle grazing on aspen regeneration. Unpublished master's Thesis, Brigham Young University, Provo, Utah~ 72p. Davis, B. N. K. 1965. The immediate and long-term effects of the herbicide MCPAon soil arthropods. Bul. Entomol. Research, 56:357-365. Day, M. w., c. L. Hammer, and A. J. Panshin. 1952 Preliminary observations on the effect of 2,4-0 93 and 2,4,S•T on aspen. Michigan Agric. Expt. Sta. Quat~ Bul, 34:266-274. Dobson, N. 1954. Chemical sprays and poultry. Agricul• ture (London), 61:415-417. Ounechie, J. f. and w. w. fletcher. 1967. Effect of some herbicides on the hatching rate of hen•s eggs~ Nature, 215:1405-1407. Durrant, s. 0~ 1952. Mammals of Utah. Univ. Kansas Publ. mus. Nat, His\., 6:1-549. Hansen, R. M~ end A. L, Ward. 1966, Some relations of pocket gophers to rangelands on Grand Mesa, Colorado. Colorado Agr. Expt. Sta. Tech. Bul., 8811-20. Hanson, w. R. 1952. Effects of some herbicides and insacticides on biota of North Dakota marshes. J. Wildl. Mgmt~, 16:299-308. Hayne, 0~ w. 1949. Two methods for estimating population from trapping records. J. Mammal., 30:399•411. ~ Hayward, c. L, 1945. Biotic communities or the southern Wasatch and Uintah Mountains, Utah. Great Basin Net,, 6:1-124. v ______• 1948. Biotic communities of the wesatch chaparral, Utah. tcol. monogr., 18:473-506. Johnson, D.R. 1964. Effects of range treatment with 2,4-D on food habits of rodents. Ecologyt 451241-249~ · Johnson, 0~ R. and R. M. Hansen~ 1969~ Effects of range treatment with 2,4-0 on rodent populations. J. Wildl. Mgmt., 33:125-132. 94 Kaith, J. o., R~ m. Hansen, and A. L. Ward. 1959. ,£ffect of 2,4-0 on abundance and foods of pocket gophers.

J~ Wildl. Mgmt., 23:137-145. Krefting, L. w. and H. L. Hansen. 1969. Increasing browse for dear by aerial applications of 2,4-D. J~ Wildl. fflgmt., 28:435-444. maxwell, R. c. and R. F~ Harwood. 1960. Increased repro- duction of pea aphids on broad beans treated with 2,4-D~ Ann. Entomol. Soc. Amer., 53:199-205. may, J. m~ 1969. Toxicity and hazards to man, domestic animals, and wildlife from some commonly used auxin herbicides. Residue Reviews, 26:37-62. mueggler, w. F. 1966. Herbicide treatment of browse on big-game winter range in northern Idaho. J. Wildl. Mgmt., 30:141-151. Odum, t. P. 1950. Bird populations of the Highlands Plateau (North Carolina) in relation to plant succession and avian invasion. Ecology, 3115£7-605. Ogle, R~ E. and c. F. Warren. 1954~ Fata and activity of herbicides in soils. Weeds, 3:257-273. I ~ Ostle, B. 1963. Statistics in research. The Iowa State Univ. Press. 585p. Park, o. ands. r. Auerbach. 1954. Further study of the tree-hole complex with emphasis bn quantitative aspects of the fauna. Ecology, 35:208-222. Roberts, R. E. and B. J~ Rogers. 1957. The effects of 2,4,5-T brush spray on turkeys. Poultry Sci., 36:703-705. · 95 Robinson, A~ G~ 1959~ Note on fecundity of the pea aphid

Acyrthosiphon pisum, caged on plants of broad bean Vicia faba, treated with various plant growth- regulators. Canada Entomol~, 91:527-528~ Robinson, M~ E~ 1966. Progress report: the sheep CTeek water evaluation project. Unpublished Report, U~S. Forest Service, Richfield, Utah. lOp. Rogers, G., o. Julander, and w. L~ Robinette. 1958. Pellet-group counts for deer census and range-use index. J~ Wildl. Mgmt., 22:193-199. Sharp, W~ M. 1963! The effects of habitat manipulation and succession on ruffed grouse. J. Wildl. Mgmt., 27:664-671. Shelford, V~ E~ 1929. Laboratory and field ecology~ Williams and Wilkins, Baltimore~ 608p. Smith, G~ E~ and B~ G. Isom. 1967. Investigation of effects of large-scale applications of 2,4-D on aquatic fauna and water quality. Pesticides monit~ J~, 1:16-21. Speth, R~ L. 1969. Social structure of small mammal populations at the National Reactor Testing· Station, Idaho~ Unpublished Dissertation, Brigham Young University, Provo, Utah 134p~ Tietjen, H.P., c. H. Halvorson, P. L. Hegdal, and A. m. Johnson. 1967. 2,4-0 herbicide, vegetation, and pocket gopher relationships. Black Mesa, Colorado, Ecology, 48:634-643~ 96

Wahlen, B. 195 □• a1na och hormonderivaten. Vaxtskyddsn- otiser, Stockholm, 14:45-54. Whittaker, R~ H~ 1052. A study of summer foliage insect communities in ths great Smoky mountains. Ecol. Monog., 22:1-44. 97

APPENDIXI

Vegetation Analysis on Aspen Type at Sheep Creek Watershed 8

Control Treated

1964 1970 1964 1970

Vegetation and Litterb 98 100 96 100 Bare Groundb 2 4 Production° Total Vegetation 723 1000 772 3783 Grass 188 213 299 3617 Forbs 446 623 366 126 Compositionb Grass 26 21 39 96 Forbs 63 62 47 3 Shrubs 11 17 14 1 Treesd Populus tremuloides Trees per acre 926 730 Seedlings per acre 1133 8500 Shrubs 8 Amelanchier alnifolia 1 1 Barberis repens 3 2 1 T Quercus gambelii 1 2 Ro9a spp. T 2 1 T §xmehpricarpos •PP• 7 7 10

8 data collected by U.S. Forest Service personnel in the vicinity of the aspen small mammaltrapping grids bin percent 0 dry weight pounds per acre 0data collected in 1967 by u.s. forest Service personnel 98 APPENDIXI (continued)

Control Treated

1964 1970 1964 1970

Grassss 9 Agree~ton trachvcaulum 4 2 2 9 Bromus inarmis 3 1 4 6 8£omus marginetue 1 4 Qpctvlis glomereta 5 Elymys glaucus 15 14 17 44 restuca ovina 1 T Poe pratensis T 1 14 30 Stipp oplumbiana ,.3 T Trigetum spicatum 2 F'orbs9 Achillea millefolium 3 2 2 1 Agoeeris spp. T 1 Aguilegia spp. 1 Aster spp. 1 1 1 Cgstilleja angustifolia 5 T 1 Cirsium spp. 1 1 C2rallorrhiza spp. 1 Delphinium barbeyi 8 F'r;agaria spp. 1 1 F'raserg speciosa 1 2 1 Galium boreale 2 2 ~•ranium richerdgonii 4 4 T T Halenium hoopesii 12 15 8 Lathyrus spp. 6 1 T Oemarhiza chilensis 5 5 1 T Potentilla spp. T T Rudbeckia occidentalis 2 1 Smilacino racemosa T T Stellaria jamesiana 1 2 2 T Teraxacum officinala 2 2 7 7 Thelictrum fendleri 1 4 1 T Valeriona spp. 2 Vicie americona 15 1 18 T Viola spp. 2 3 1 T

8 in percent based on dry weight 99

APPENDIXII

Vegetation Analysis on Grass-forb-Shrub Type at Shaap Creak Watarshad8

Control Traeted

1964 1970 1964 1970

Vegetation and Litterb 67 87 65 87

Bara Groundb 31 13 34 11

Rock and Pavemantb 2 1 2 Productionc Total Vegetation 765 1329 975 1222 Crass 594 794 668 1127 f'orbs 171 511 307 85 Shrubs 24 10 Campositionb Grass 78 60 69 92 F"orbs 22 38 31 7 Shrubs 2 1 Graseesd Aarppyrontrachycaulum 8 3 6 4 Agrostia spp. 1 Brgmus merginetys 21 23 14 2 Oectylie ~lomeretp 1 f"petucp ovine 1 Hordegmbrgchxantherum 1 12 Malicgbulbpsg 1 Phlaum alpinum 3 Paafandleriong 1 Pop pratansis 33 26 26 52 Stipp 90lumbiana 3 5 1 1 §tip1 l1ttermni 3 3 1

8 data callactad by u.s. f"orest Service personnel in the vicinity at the mgadowstudy plots in percent 0 dry weight pounds par acre 100 APPENDIXII (continued)

Control Treated

1964 1970 1964 1970

Grasslike Ptantsd Cgrax spp. 1 6 17 Juncus spp. 1 12 1 Forbsd Acbillea millefolium 3 5 1 1 Agpseris spp. 1 3 1 T Aster spp. 1 4 1 T Castillej9 angustifolia T T Cirsium spp. , T 8 5 1 Collomia spp. T T T Delehie!um spp. T T Descurainia spp. T T Erigeron spp. 1 Halenium hoopasii 2 5 1 lllad!a glomerata 3 2 1 Polanisia dodecandra T T T 1 Potgntilla spp. T 1 1 T Senecio spp. 2 1 Stellaria jamasiana 1 2 1 1 Taraxacum officinale 4 3 8 Vicia americana 1 1 8 T Viguiero multiflora 5 1 1 Shrubsd Barberis repens 1 Rosa spp. 1 1 Sl!mehoricarpos spp. 1

din percent based on dry weight THE EFFECTS or HERBICIDE APPLICATIONS ON THE ANIMAL POPULATIONS or ASPEN COMMUNITIES

Carl E. Wadsworth Department of zoology and Entomology Ph.D. Degree, August 1970

ABSTRACT

Approximately 475 acres of aspen, oak brush, and grass-forb-shrub communities were treated with herbicides. The populations of arthropods, birds, and mammals were investigated on treated and untreated areas and the results were compared. There was no difference between soil arthro pod populations on treated and untreated aspen plots but a significant increase in these populations on treated meadow plots� The foliage insect populations were significantly lower on the treated aspen plots but were significantly higher on the treated meadow plots� The aquatic inverte brates were not affected by the treatments. Bird popula tions ware lower in the treated area during the nesting season (June), higher in the treated area during July and August and nearly the same in each area during September. Small mammal populations decreased significantly on the treated meadow plots. Microtus populations increased while all other small mammals decreased in numbers on treated aspen plots. Use of the treated areas by mule deer was significantly reduced, while use of the same areas by elk was slightly increased.