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RA56 51 URL-TWEED BIGHORN SHEEP INYESTIOTION(U) MONTANA DEPT 1/27
OF FISH AND GANE HELENA 6 W BROWN 1979
UNCLSSIFIED DRW77--03F/06/3 NL
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NATIONAL BUREAU 0F STANDARDSMICROCOPY RESOLUTION TEST CHART
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SECURITY CLASSIFICATION OF THIS PAGE (%hen Data Entered)
READ INSTRUCTIONSREPORT OCUMENTATION PAGE BEFORE COMPLETING FORM
'. REPORT NUMBER 2. GOVT ACCESSION NO. 3. RECIPIENT'S CATALOG NUMBER
4. TITLE (and Subtitle) 5. TYPE OF REPORT & PERIOD COVERED
Ural-Tweed bighorn sheep investigation Final Oct.1,1976-May 31,1979
6. PERFORMING ORG. REPORT NUMBER
7. AUTHOR() 8. CONTRACT OR GRANT NUMBER(s)
Brown, Gerald W. DACW67-76-C-0083
9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT, TASK 0AREA & WORK UNIT NUMBERS
MONTANA.DEPARTMENT OF FISH AND GAME
i. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE
US Army Corps of Engineers [1979]Seattle District, P.O. Box C-3755 13. NUMBER OF PAGES
Seattle, WA 98124 9414. MONITORING AGENCY NAME & ADDRESS(If different from Controlling Office) IS. SECURITY CLASS. (of this report)
AD-A 156 051 Unclassified
15a. DECLASSIFICATION/DOWNGRADINGSCHEDULE
16. DISTRIBUTION STATEMENT (of this Report)
Th --docu-ment has been approvedI r c tl'hic , xol se and sale- itsdit:iibt!ion is unlimited.
17. DISTRIBUTION STATEMENT (of the abstract entered In Block 20, It different from Report)
18. SUPPLEMENTARY NOTES ,
19. KEY WORDS (Continue on reverse aide if necesaery Md Identify by block number)
r Bighorn sheep )habitat degenerationhabitat lossLungwormsLake Koocanusa
20. ABSTRACT (Corthue e ,evese slob if nrcoeaty and identify by block number)
Investigation of declining status of the Ural-Tweed bighorn sheep herd. Sheep •were captured and equipped with telemetry collars. The sheep population wasfound to be a contiguous herd which made recurrent use of specific key areasthroughout the range. Natural as well as human decimating factors are discussedin relation to their overall influence on the shoop population. Recommemdation'
for management of the Ural-Tweed sheep herd and its habitat are specified.
OTIC FILE COYDO JAN7 1473 EDITION OF I NOV 6S IS OBSOLETE
SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered)
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!lnclor contrac I the 1.. Arr-y Corps of P'nrirjears, thn ?Mont:-I I'-rn-rtmf'ot of Fish r:.q-lo ijti~o-- ; r an vectir-atir of t -j dec.inin:- st,tp7of tha !Ira 1-Twed 'ir-hnrn sh-T br on, 1 Octorne I " The sturv u-, t.no~er-
snended fro- ?-~v throuchNner.. 0? rwa n lpted on 11 'WAV107. Pvn hirrorp Sh-er~ori.nr o" 3 sewes Ano 4 r y'= P~~e rrturpd Ann
~''Ddwith, tPIer'etrv rollairs. Two hii-viron and r ix relocatirnnz of r;:rnic-crnllared sheep nroviried informatinn on se~sorial distribution and! movernents, ka.'use areas, home ranre size, habitAt. selpction ind population nivnarricq. Th esheenP population, estin'aptod at fewer thpn 25- Primal-, war foune to ba P conti-u-ous herd which rn~de recurrent use of specifir key areps throurhout thg' ranr-e.UrPI-Tweed biphorns were consistent in their use of Isouth, southwe-st, and westel)-Osed overs -teepenod terrain alonr~ the east escarpment of Lirke KoocanusQ. Fivehabitat types, PSME/SYAL, PSIIE/CARU, PSMF'/PHMA, PSME/AFUV and PSM'E/LI0'received
ri 100 percent of the sheep use annually, based on telemetry relocations. Grassyopenings and open forest cover types~ consistinp of sparsely stocked, but lar,;ediameter ponderosa pine and Douzlas-:fir~characterized sites selected by sheepdurinr most seasons of the year. FRough fescue was found to be an importantdietary constituent throughout the year, while browse, as a forac-e class, wasimportant durin7 periodr of hriwy-crusted snow, conditions and also durin- sorin7rflowerinr-. Endopzrpsite loads wer- low, but the poz-sibilit: of a populatincrash due to the lunrworm-mneunionia cornlx durin- the ,9601's is discusr-d.Thirtv-fiv- hundred acres of hirhorn shefn habitat lost to Lihb,' ta Pro.i,'-t
nd de-enprR-tion of ro-4idual habitat dJu~.o ecolo!-icnI nuccersion in th-', renc"nf n;Aura2 fires con4-iitter to reduce thr' ;;rr*,n- c,--icitv of the rpn-. ?Thtural
f- aCI!P human-cauisc4 decimptir, fictors are dinctif.-t -4- relantiorl to thairnliprall influence on the sheep population. Peromndnionr- f~r r.nnaement ofth -~UT~e rhee- herd and its hatitat Pre forwprd'tl'..
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Capture Pr !1-rkeinf Ter!-iiqlies 2r,
Puttin- 5 re
Snrin - r~
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4. ~e-o~ cii"re,-t-rr P-, Par- Sie rv W'-~
Statlstir- fnr Biarhnr- V-heer~ C. 47
7. Seasonal Act'vity Centers, H4ome Panve Size and kovernentStatistics for Fig'hor' Sheen D. /.
0 Seasonal Artivity CetrHm aceSize Pnd Moveent
P. Se-onp1 Artivitv C'erter~t, %ine Rp-nqe Si7zo anH mnvernent
J1. Monthly Snatji l and Ternorpl Tistrihufinn of vnrk-, Pil-horn- . Pelor-tion-, For nne Year Showinr Number of Relorptiors/
12. Monthly Piinon 9 eo T1,4e of Various Ver-ctp-tion- Cover T-u-n-p D)PscribnH ^n the Study Area.
13. !Monthlv Pihorn Sheen Mz- of 17:riowz Hahit~pt Type- on thn
Ural-Tuped Sheep Panrp.. r
14. Monthly Pirhorn Sheep Use of the V~rious Lnnf-o TypesD !escribed For the Study Ara
15. Monthly Pi~hnrn Sheep Use of V7-rious Pspcts nn the StudArep.
16,. Monthly Pip horn Sheen Use of F1ovation nnd S o~l- th-Tlra)l.Tweor1 5'h-pr.,-.
17. Annly!se- of Timber Stand Ch rA-t-ri~tic- n' r~ q1ect~aby Pi rhorn Sheep) on tho llrlTied Sh-rn Pp)-
~Results of Endonirsitp -,alvsis of Five Bi'orn She-nCprcasse- Found on the Ur.]-Tweed Ftudv Arep. 71
19. Protostronrvlid Larval Pis:hartr for Url-Tw PP Piphorn-Sheeo As Determined From 50 Fecal Samnles CollectedBetween Octnbpr 1976 and March 1977. 73:
20. Protostronrylid Larval Discharge for Ural-Tweed BirghornSheep As Determined From 240 Fecal Samples Collected ona Monthly Schedule Between January and Dec-her 1978. 74
21. Rumen Analyses of Two Tllegally Killed Piphorn YearlinrsCollected at Sheep Creek on 24 October 1976. 75
22. Percent Relative Density of Plant Fragments In BighornSheep Fecal Samples Collected on a Monthly Basis forCalendar Year 1978. 76
23. Population Estirqtes for Ural-Tweed Herd, llsin7 a CohortCompletion-Total Count Method. PO
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1. Study Ar .
?. Oblicue AerU.] Phntrora~h Looriv- Fast Tnto Sh-D Creek
3. Fire Histor" or, Ura!-Twe- 'qhpen Pan- ,,
4. ComDarative Aerial Photo-ranh of Lower Cripple Horse Cre'k,Showing' Successional Chanrps in Vegetation 10
5. Traps Used Durin. Studv 13
6. Flindfolde6 Youn. Pan, and Radio Collar 14
7. Trappin- and Casualt,, Form Sheet 15
8. Data Collection Form Sheet 18
9. Cover Types on Study Area 20
10. Habitat Tmprs on Stuvy Area 22
)l. Landforr Types on Study Area 23
12. Photos of Study Arimals A, C, E, F and G ?
11. Movements of Ram P. 29
34. Movenents of Fwe B. 30
15. Movements of Pam C. 31
16. Movements of Eve D. 32
17. Movements of Pim F. 33
IP. Movements of Pve F. 34
19. Movements of .am G. 35
20. Site Specific -elocations for Radio-Collared Shoep 3
21. Seasonal Key Use Areas for Sheep on the Ural-Tweed SheepRanize. 52
22. Lambinr-Nursery Area at Allen Gulch. 60
23. Hirhway Fatality and Natural Mortality of Birhorn Sheepon the Study Area. 82
24. Rock Cuts Alonr Highway 37, Barrier to Sheep Movement. 88
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CHAFTEF I
IN7TRODUCTION
Seton (19291 estimated between 1.5 and 2 million bighorn sheep, (Oviscanadensis), in North America during the 1800's. By the early 1940's, thisspecies was extirpated in four of the fifteen western states they formerlyinhabited. Within the remaining states, their distribution was reduced to ap-proximately ten percent of their former range, and their numbers diminished toless than 20,000 (Buechner 1960). Probable causes for their decline are: 1)forage competition with domestic, as well as wild ungulates; 2) disease intro-duced by domestic livestock; 3) conversion of mountain grasslands into timber-lands or sagebrush deserts (Morgan 1971); 4) indiscriminant hunting, and 5)human encroachment and development on key bighorn ranges.
In an attempt to rectify this situation, several states initiated reintro-duction programs to restore bighorns onto historic range (Yoakum 1963). TheMontana Department of Fish and Game began transplanting activities in 1942.Results of reintroductions varied from complete failures to establishment of afew huntable populations. A notable characteristic of bighorns introduced ontounfamiliar range was an inability to establish migration routes between seasonalranges. For mountain sheep, knowledge of home range and migration routes istransmitted from generation to generation and appears to be a learned trait innative herds (Geist 1971). Once indigenous herds perish, home range knowledgeis lost with the results that introduced sheep are frequently unable to exploitpotential seasonal ranges.
The Ural-Tweed bighorn sheep herd, inhabiting the East Kootenai adjacentto Lake Koocanusa, is the last remnant native population of bighorn sheep innorthwestern Montana. Historically, the Ural-Tweed sheep range was more extensivethan it is today and supported a viable population of mountain sheep. Chrono-logical population estimates for this herd by Ensign (1937), Brink (1941), Bergeson(1942), Couey (1946), Zajanc (1948), Blair (1955), and Quick (1965), were 97, 100,98, 150, 168, 150-175, and 170, respectively. This information suggest an expan-ing population into the 1950's which appears to have stablilized at 150-200 animalsby 1965. Since that time, a drastic decline in sheep numbers has occurred. Pres-ently, there are no more than 25 bighorn sheep remaining on the Ural-Tweed range,and their future as a viable sheep herd is in doubt.
Several factors, including natural as well as human induced phenomena, havebeen responsible for the overall demise of the Ural-Tweed sheep population. Habi-tat loss to Libby Dam Project and successional trend on residual habitat havedramatically reduced the carrying capacity of the sheep range. In addition, asheep population crash associated with the lungworm-pneumonia complex may haveoccurred concurrent with Canadian sheep herd declines in the 1960's. However,there is no documentation to confirm this speculation.
Libby Dam Project resulted in substantial reduction of bighorn sheep habitatalong the Koocanusa Reservoir face. Inundation of the impoundment area directlyremoved approximately 3500 acres of critical bighorn winter-spring range. Addi-tional key habitat was lost to construction of Montana State Highway 37 whichbisects the sheep range from Fivemile Creek to Pinkham Creek. This highway
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traverses a documented lambing area (Brink 1941), rutting grounds, winter range,and spring razee in the lower slope area between Volcour Gulch and Peters Gulch.High-speed vehicle traffic along this highway has applied additional stress onthese animals through vehicle-sheep collisions as well as general harassment ofsheep attempting to cross the roadway. Increased access onto the sheep range,brought about by the highway, has resulted in several animals being illegallyshot. The loss of 13,800 acres of big game winter range to Libby Dam Projectfurther compounds range problems encountered by these sheep. Documentation inthe literature suggests that bighcrns demonstrate a competitive inferiority whencompeting with sympatric ungulates for available forage. Interspecific, as wellas intraspecific competition for forage and space would undoubtedly provide aselective advantage for other ungulates over sheep, with consequences beingmanifested in a downward adjustment in the sheep population through a generaldecrease in productivity and lamb survival.
Through time, ecological succession has been a subtle but, nonetheless,important factor responsible for vegetation changes on the sheep range. Rigorousfire suppression has allowed advanced stages of plant succession on an area pre-viously maintained as a fire disclimax, with the end result being reduced supportcapabilities on habitats which were formerly more open and maintained greaternumbers of sheep.
Considering the impacts of Libby Dam Project on the Ural-Tweed sheep herd,the Montana Department of Fish and Game requested funding from the U.S. Army,Corps of Engineers to initiate an investigation of this sheep population. Over-all purpose of the project was to gather biological information applicable toformulation of management guideline-, to perpetuate a viable sheep population onresidual range. Specific study objectives included the following:
1) Delineate seasonal ranges, migration routes and key use areas;2) Determine habitat parameters being selected for by sheep during various
seasonal periods;3) Determine herd health as it reflects range condition;4) Monitor population dynamics (i.e. productivity, recruitment, mortality,
age and sex composition to assess herd status and trend, and identify possiblefactors limiting herd growth; and
5) Identify critical areas of potential vehicle-sheep collisions alongState Highway 37.
This investigation was initiated on 1 October 1976. Due to an extremelymild and dry winter, terms of the contract requiring six bighorn sheep be instru-mented with telemetry collars could not be met. After discussion of this situa-tion with the Corps of Engineers, it was determined advantageous to temporarilysuspend work on the project after 30 April 1977, rather than proceed through asumner season with an insufficient number of rad~.o-collared animals. The secondphase of the project comenced on 1 December 1977 with intensive field work beingcompleted on 31 December 1978.
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CHAPTER II
DESCRiPTION OF THE STUDY AREA
Location
The study area is situated along the east side of Lake Koocanusa betweenFivemile Creek in the south and F.nkham Creek in the north (Figure 1). Theproject area is accessed by State Highway 37 which enters the southern extremeof the sheep range approximately 30 miles northeast of Libby, Montana. Earlyreports (Ensign 1937, Brink 1941) suggest the northern limits of sheep distribu-tion to be Beartrap Mountain. Sheep sightings north of this point recommendedextension of sheep range delineation to include lower Pinkham Creek. Conversely,sheep were not observed in the upper Cripple Horse drainage near Warland Peak,an area known to be historic sheep range. Consequently, this area was deletedfrom the study area map.
Topography
With a North-South orientation of the sheep range, westerly exposuresoverlooking Lake Koocanusa predominate. Several drainages and small tributariesincluding Pinkham Creek, Sutton Creek, Peck Gulch, McGuire Creek, Tweed Creek,Rocky Gorge, Allen Gulch, Peters Gulch, Sheep Creek, Tenmile Creek, PackratGulch, Volcour Gulch, and Fivemile Creek dissect the area from east to westproviding south and southwesterly aspects.
Generally, topographic features of the area are conveniently divided intotwo distinct components: 1) the initial escarpment sloping from high pool levelof Lake Koocanusa, 2,459 feet, to a deflection point which approximates the 4,800foot elevation along the reservoir face, and 2) the more gentle terrain rangingfrom upper elevation limits of the reservoir escarpment to subdued ridges andpeaks ranging to 6,872 feet on Sutton Mountain. The escarpment consists of over-steepened terrain with high relief ratios where elevational changes of 2,500 feetoccur in less than 1.0 mile and slopes average 50 percent. Rocky, broken terrain,talus slides, cliffs and discontiguous benches or bluffs are characteristic land-forms along the escarpment (Figure 2). Geomorphic features on areas above theescarpment are less pronounced, with rock outcroppings and exposed parent materialoccurring infrequently throughout this component of the study area. Soil develop-ment and stability are greater than that found on the escarpment.
Soils, landform and geologic structure are discussed in some detail in theInch Mountain Planning Unit, Final Environmental Statement (Anonymous 1974).
Climate
Climatological data for the general vicinity are collected by the U.S.Forest Service, Libby Ranger Station which is located in Libby, Montana approxi-mately 20 air miles southwest of the study area. Table 1 lists monthly meantemperatures and precipitation for 1976-1978 and also shows departures fromnormal mean temperatures and average precipitation based on long-term weatherdata collected at the station.
Annual precipitation averages 19.4 inches with approximately 50 percentoccurring as snow in the higher elevations. Maximum precipitation occurs during
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ui, NO. TiA PC BSO DATE TIME
NO. SH-iEEF GROUP TYFE: EVE-JUVENILE RAJUVEN-JUVENiLE ?M-EE FL.: EWE JUVLI;2LLNO. AU'. EW-S NOC. YEA.LTh, EW-S N. LAJ'3
NO. YNLG EARS 1 O. 2Y NO. 3Y. NO. 4YR NO. 5YR 195P.SyF NO. , 10 NO. E -7
NO. UNCLA.SSIF!E SHEEr NO. MARKED SHEEP ANIJ L 1O.
A C I Y: BEDD2 F EE.I2 ALEFT WALKIN, RUNNING -SCAPIN'- O hE
LOCAT!IN: HWY. MILE C. T 1 R W 1wT: LO LA
ELEVATION SLOPE: MdCFC MAP ASPECT: 339-23 24-66 69-113 114-15E 159-203 204-248
249-293 294-338
TOPOGRAPHY:: TALUS CLIFF BLUFFS RIDGE BRO1EN SIDEilLL
TE!-,PEFATTURE: BELOW 0 0-20 21-40 41-60 61-80 82 plus
WIND SPEED: 0-3 4-10 11-20 20 plus WIND DIRECTION: N NE E SE S SW W NrW
CLOUD COVER: 0-25% 23-50 51-75% 76-200%
PRECIPITATION: DRY LIGH RAIN STEADY RAIN SNOW FLURRIES STEADY SNOW FOG
GROUND: DRY DA X? MUD7* FROZEN HEAVY FROST PATCHY SNOW UNIFORMX SNOW COVER
SNOW DE r: 1-3" 3-6" 6-9" 9-12" 12-15" 15-18" 16" Plus
SNOW CONDITION: POWDER WET PACKED CRUSTED FROZEN
SUBSl RATE: EFXD, Dc TALUS ROCKY SOIL DEVELOPED SOIL
COVER TYPE: ROCKLAND SHR UB-GRASS PARKS OPEN FOREST CLOSED FOREST
HABITAT TYPE: CANOPY COVERAGE: 0-20% 21-40c. 41-60% 61-80% 81-100
NEAEST CLIFF: NEAREST S:EEP TERRAIN: NEAREST CONIFER SPECIES DBH
TZIHER STANkD CHARACTERISTICS
DBH CLASS
PECIES
FIGURE 8
Habitat Selection
In addition to seasonal range use and movement patterns information providedby telemetry equipment, specific data on site selection were obtained each time 0an instrumented animal was located. Biotic and abiotic factors such as vegetationcharacteristics, topographic and geomorphic features and climatic conditions wererecorded to establish the relationship between habitat situations being selectedfor during different seasons and under variable climatic conditions. A datacollection form sheet was develo;,cd and used to record information at relocationsites (Figure 8). S
Cover Type
A cover type classification scheme for the study area was developed utilizingcanopy coverage of existing vegetation as the determining factor in differentiatingcover types. Five broad cover types were recognized on the sheep range and are Sdescribed below:
1) Rockland is characterized by a low total canopy coverage of bryopbyticas well as non-bryophytic vegetation. Lichens, mosses, scattered shrubs, grassesand forbs growing on talus slides and rock outcrops typically distinguish thiscover type.
2) Shrubland-grassland complex. Shrub-grass plant communities occur onlyminimally on the study area, and are generally restricted to previously disturbedsites [i.e. logged, burned) where early successional stages of shrub-grass associa-tions persist. The bitterbrush-bunchgrass plant community near the mouth ofSutton Creek and the logged areas at Allen Gulch and Volcour Gulch are represen- Stative of this cover type. Conifer canopy coverage is less than 25 percent whilecoverage values for grasses and shrubs generally exceed r percent. Depending ontopo-edaphic factors, common shrubs found on this type are bitterbrush, service-berry, ninebark, mock-orange, and chokecherry, while bluebunch wheatgrass, roughfescue, Idaho fescue, Junegrass, and purple reedgrass are typical graminoids onthis cover type.
3) Parks are characterized by canopy coverage values of less than 25 percentfor both conifers and shrubs, but by comparatively high coverage values, 50-75percent, for graminoids and herbaceous plants. Common perennial herbaceous floraincluded yarrow, arrowleaf balsamroot (Balzamorhiza sagittata), wild buckwheat,strawberry (Fragaria vesca), alumroot, lomatium (Lematium macrocarpum), penstemon, Sand phlox (Phlox hood 1). The two dominant bunch grasses growing on this covertype were bluebunch wheatgrass and Idalho fescue. With respect to total area,parks are not a common cover type on the study area but typically occur at upperelevations along the interphase between the reservoir escarpment and upper slopeforested areas.
4) Open Forest is the characteristic cover type on the warmer and drieraspects of the reservoir escarpment. Conifer canopy coverage ranges between25-75 percent, while collective shrub coverage was 5-75 percent and grass coveragealso ranged from 5-75 percent.
5) Closed Forest is the predominant cover type over much of the study area,especially at the higher elevations above the steep reservoir face. Intrusionsof the closed forest cover type occur at lower elevations particularly or the
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Telemetry equipment. was purchased thro,-ih AVM Instrument Company, Champaign,illinois. Radir-c-:clars, preassemnied at the factory, were of the LM type withSB2 transmitters powered by one (1l lithium battery, and ranged in frequency fror.150.860-152.132 Kiz. The standaro LA 12 receiver with sweep option was useo onthis project. Two strut-mounted 4-element yagi antennas in conjunction with aright-left switch box, were employed during aerial trackinF of radio-collaredsheep. A single hanc-held 3-element yagi antenna was used while ground trackingradioed animals.
Telemetry relocations were made initially from aircraft, with subsequentground confirmations that normally provided visual contact with the instrumentedanimal or at least signs of its activity in the immediate area of the radio "fix".Ground initiated tracking of radioed sheep and resultant plotting of the locationwas not determined through triangulation, but rather, was established throughdirect observation. All locations of marked sheep were plotted on U.S.G.S.1:24,000 scale (7.5 minute) topographic maps with 40 feet contour intervals.Oblique aerial photographs of the study area aided in accurate determination ofeach relocation site. Each radio-collared bighorn was located approximately fourtimes monthly throughout the functional period of the transmitter.
Distribution and Movements
In conjunction with telemetr-, relocations, reconnaisance trips were madeover the study area to establish sheep distribution through direct observationof animals or their sign (i.e. tracks, beds, pellet groups). Due to the rugged,broken, well-forested nature of the Ural-Tweed sheep range, assessment of sheepdistribution through random reconnaisance was very time consuming and unproductive.The telemetry system proved absolutely essential to the collection of sound datafor all facets of the project. Telemetry apparatus permitted relocation of sheepin both open and timbered habitats, wherear random observations of bighorns werebiased towards openings, mostly adjacent to State Hizhway 37. Radio-collaredsheep provided reliable data on seasonal home ranges and key use areas, seasonaland short-term movements, migration routes, habitat selection, population numbers,group fidelity, and herd structure.
Continued use of areas between State Hirhway 37 and Libby Reservoir neces-sitates sheep crossing of the roadway. Specific crossing points have been adoptedby these animals and these sites were identified and located with respect to thenearest highway milepost.
Data for movements, seasonal centers of activity, and minimum home rangesizes for marked sheep were analyzed on an IBM Computer, utilizing a programdeveloped by the Montana Department of Fish and Game, Research Bureau. The UTMGrid system was drawn directly on U.S.G.S. 1:24,000 scale topographic maps tofacilitate precise plotting of a radioed animal's location down to the nearest2.5 acres (1 hectare) area. Grid coordinates for individual relocations were key-punched on IBM Computer Cards and line printouts edited for errors prior toanalyses by the computer. Computer printouts provided calculations on home rangesizes, distances moved, geographic centers of activity, and standard diameters foran individual marked sheep during a given time period. The standard diameter rep-resents the diameter of a circle with the center of activity as its center, andwhich contains 68.26 percent of all relocations of an animal during the periodconsidered.
RFPRODOCFU) AT GOVFRNMENT FAPENSE
0
DISCLAIMER NOTICE
THIS DOCUMENT IS BEST QUALITYPRACTICABLE. THE COPY FURNISHEDTO DTIC CONTAINED A SIGNIFICANTNUMBER OF PAGES WHICH DO NOTREPRODUCE LEGIBLY.
TRAPPING/CASUALTY FORM
COLLECTION NO. SPECIES DATE TIME •
SEX AGE
LOCATION OF CAPTURE OR DEATH
TRAPPED OR DRUGGED DRUG USED DOSAGE 0
TIME OF INJECTION TIME DOWN TIME RECOVERED
CIRCUMSTANCES OF DEATH
PHYSICAL MEASUREMENTS
WEIGHT: WHOLE FIELD DRESSED
TOTAL LENGTH SHOULDER HEIGHTH CHEST GIRTH
EAR LENGTH TAIL LENGTH HIND FOOT LENGTH
NECK CIRCUMFERENCE: AT SHOULDER AT SKULL MIDSECTION
HORN MEASUREMENTS 5
LENGTH: BASE-i 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10 TOTALRIGHT-
LEFT-
CIRCUMFERENCE: BASE 1 2 3 4 5 6 7 8 910RIGHT-
LEFT-
TIP-TIP SPREAD 5
EAR TAGES: RIGHT LEFT
RADIO COLLAR: CHANNEL COLOR
FIGURE 7
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CHAPTER~ III
MATERIALS AND METHODS
Capture and Marking Techniques
In an attempt to satisfy contract stipulation that six bighorn sheep becaptured and fitted with telemetr:',-collars, initial project emphasis during the1976-77 field season centered on trapping activities. Five clover traps and twodouble-gated Oregon style panel traps (Figure 5) were established adjacent toState Highway 37 between Tenmile Creek and Peters Gulch, in an area normallyoccupied by sheep during winter. A small drive trap, consisting of nylon nettingwings funneling into a nylon netting trap enclosure of approximately 20 x 30 feet,and with an animal-triggered drop gate mechanism, similar to that used on theOregon panel traps, was constructed in the timber at a major sheep crossing alongHighway 37 near Sheep Creek. Traps were baited with alfalfa-grass hay, and acommercial livestock sweet-feed mixture consisting of rolled oats, barley andmolasses. Apple pulp used successfully on bighorns in Colorado (Schmidt 1971)was tried at two of the trapsites. In addition, 50-pound blocks of stock salt(NaCl 99 percent; inert matter 1 percent) were placed at three of the trapsitesand rock salt was scattered around one of the panel traps in attempts to establishlick-sites f or spring trapping. A natural mineral lick near Tweed Creek wasdiscovered and supplemented with block salt. Two live-snares as described byMassman et al. (1963), were set on trails leading to this lick site. During the1977-78 winter, an additional wing trap (Figure 5) was established at anotherimportant sheep crossing along State Highway 37 near Sheep Creek. All trapswere checked at least once each day and snares were inspected twice daily whilein operation.
At appropriate opportunities, attempts were made to immniobilize free-rangingsheep with Sernylan (phencyclidine hydrochloride) or Rompun (xylazine) in aqueoussolution, contained in hypodermic syringe darts propelled from a Palmer powdercharged Cap-Chur rifle. Sheep were darted directly from a stationary pickuptruck along State Highway 37, as their avoidance response to a vehicle was muchless pronounced than their reaction to a man on foot. Initial attempts to stalkbands of sheep for purposes of darting proved unproductive and were abandonedsince this activity tended to increase the already wary nature of these animals.In conjunction with a helicopter survey of the sheep range, an attempt was madeto dart a bighorn sheep from the air. Animals captured in traps were not subjectedto tranquilizing agents, but were manhandled and their legs secured in a fashionsimilar to that of tying up a calf. A blindfold (Figure 6) was used on trappedanimals to reduce stress induced through handling. Darted animals generally de-parted the area quickly and were allowed several minutes travel time prior topursuit. They were then tracked to where they had succumbed to the drug. Handlingof sedated bighorns was similar to that of handling trapped animals, in that theywere blindfolded and tied to reduce stress and the possibility of injury. Cap-tured individuals were assigned an age and sex class, and general body measure-ments were recorded on form sheets (Figure 7). Each animal was examined for ecto-parasites and general body condition was noted. Montana Department of Fish andGame ear tags were attached to each of both ears on captured bighorns and a color-coded collar (Figure 6) housing a radio transmitter was attached to each sheep.Upon release, drugged sheep were observed for several hours and relocated thefollowing day to insure full recovery. Each transmitter package was color-codedwith a wear-resistant friction tape to facilitate identification of a markedanimal in the field.
-12-
(Physocarpus inalvaceus), 3nOWterry (Symphorycarpos albus), oceanspray 1holociscusdiscolor), W?'tt spirea (Spirea betulifolia), 3erviceberry (Amelanchier alnifolia),mock--orange (Philadeiphus lewiaii), Oregon grape (Berberis repens), bearberry'Arctostaphylos uva-ursi), chokecherry (Prunus virginiana), rose (R~ose spp.),bitterbrusb (Purshia tridentata); grasses leuc wheatgrass (goyospicatuiz), rough fescue (Festuca scabrella), Idaho fescue (Festuca idhess),Junegrass (Koleria cr13i5t), pinegrass (Calamogrostis rubescens), purple reed-grass (Calamogrostis puPrescens) ; perennial f orbs: pens temon (Pens temon p.alumroot (Heuchez-a cyl idrica), wild buckwheat (Eriogonu3 herocleoides), yarrow(Achillea .illfolium). A variety of annuals and other herbaceous plants cocnalong -the reservoir face assume seasonal dominance during spring and Bumeraccording to their respective phenologies.
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November, December, and January with secondary peaks in May and June. Summersare short and r,.atively dry, with average precipitation for July and Augustbeing .68 and 1.05 inches, respectively.
S 0
The average annual temperature is 45.1 F. January is the coldest monthaveraging 22.4 F. Warmest0temperatur s are recorded during July and Augustwith monthly means of 67.0 F and 65.3 F, respectively.
The winter of 1976-1977 was the mildest on re8 ord for the Libby area.Mean monthly temperatures were 3.4-F, .9 F, and 4.2 F above the long-termaverages for December, January, and February, respectively. Conversely, winterprecipitation was well below normal with records for December, January andFebruary registering, respectively, 1.72, 2.10, 1.11 inches less precipitationthan the long-term average. The project study area reflected these extremelymild winter conditions in that the reservoir escarpment was mostly bare of snowthroughout the winter.
The 1977-78 winter period was more nearly normal, with respect to climate,than the previous year. Mean monthly temperatures were cooler in December, andslightly warmer in January and February than long-term averages, while totalprecipitation for the three month period was .83 inches below average. There was,however, persistent snowpack on the study area throughout the 1977-78 winterseason.
Fire History
Historically, fire assumed an important role in maintenance of naturalecosystems on the study area. Fire disclimax plant communities are well representedthroughout the sheep range as evidenced by burn scarred ponderosa pine (Pinusponderosa) and dense stands of lodgepole pine (Pinus contorta). Records kept bythe U.S. Forest Service, Kootenai National Forest, reveal a higher than averageincidence of fire within the Ural-Tweed Sheep Range (Figure 3, Table 2). Of69 fires recorded between 1940-1977, 53 or 77 percent were induced by lightning,a natural causative agent. With adoption of an aggressive fire suppression policyby the U.S. Forest Service since about 1930, the natural role of fire has beencircumvented. Consequently, plant succession favoring more densely forestedDouglas-fir (Pseudotsuga menziesii) dominated communities is gradually replacingopen grown ponderosa pine-bunch grass associations which are fire dependent forperpetuation. The successional trend on the sheep range, although subtle, showsconifer encroachment on previously more open sites (Figure 4). With the absenceof fire this trend will, no doubt, continue.
Vegetation
Flora in the Libby region reflects Pacific Coast Climatic influences and fallsbroadly into the Douglas Fir Coniferous Forest Zone. Many species comnon to thewest coast such as western red cedar (Thuja plicata), western hemlock (Tsaheterophylla), mountain hemlock (T. mertensiana), grand fir (Abies grand1is), andwestern white pine (Pinus monticoli) occur on the study area.
Ponderosa pine and Douglas-fir dominate the conifer overstory along thereservoir escarpment, but give way to more dense stands of Douglas-fir, lodgepolepine and subalpine-fir (Abies lasiocarpa) on the more gentle terrain sloping uptowards the Kootenai-Pinkhamdivide. Comon understory associates on the xericsouth, southwest and west aspects of the sheep range include: shrubs: ninebark
-7-
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cooler more moist northerly and easterly aspects. Canopy coverage of coniferson this type Pvc_-eds 75 percent, shrub coverage ranges from 1-75 percent andgrass coverage, especially pinegrass, ranges to 100 percent.
Photographic examples of the various cover types are shown in Figure 9.
Habitat Type
Habitat type classification follows that described by Pfister et al. (2977).Briefly, a habitat type reflects the potential vegetation association on a givenarea if allowed to proceed to successional climax. By definition, "all landareas potentially capable of prouucing similar plant comunity at climax may beclassified as the same habitat type" (Daubenmire 1968). Habitat type designationfollows a two element system consisting of 1) the climax tree species and 2) thecharacteristic or dominant understory associate. For example, Pseudotsuga menziesii/Physocarpus malvaceus, abbreviates PSME/PHMA refers to the Douglas-fir/ninebarkhabitat type.
A habitat type map overlay, on a scale of 1:24,000, was constructed forthe study area and used in conjunction with the U.S.G.S. 7.5 minute topographicmaps to determine bighorn sheep use of various habitat type (Figure 10).
Landform Types
To characterize geomorphic features being selected by bighorns, six differ-ent landform types were categorized on the study area. These types consistedof:
1) Talus-masses of large diameter angular boulders produced by backweather-ing and mass wasting of scarps or rock ou.crops. Talus slides or cones are gen-erally unstable due to continual downslope movement, and incapable of supportingvegetation to climax.
2) Cliffs-near verticle rock faces with a minimum verticle drop of 25feet and ranging to over 100 feet. Faults along cliff faces often providedavenues of travel for sheep.
3) Bluffs- a series of discontinuous benches or terraces ranging in widthfrom a few feet to over 100 feet and separated by steep to near verticle rockfaces.
4) Ridgetop-the raised line of land separating two sloping surfaces and gen-erally separating two drainages.
5) Broken-terrain of an obviously rocky nature but not qualifying as talus,bluffs, or cliffs.
6) Sidehill-steep areas generally less rocky than any of the other land-form types due to a higher degree of soil development.
Each relocation site for radio-collared sheep was placed into one of thelandform type categories. The various terrain types are shown in Figure 11.
Microsite refers to a small area immediately surrounding a sheep relocationsite. Biotic and abiotic environmental parameters were measured at each of these
. . .. .. . .. . .. . . . . . . . ....
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sites to determine characteristic features of areas being selected by bighornsheep. Abiot_ f'eatures of a site were determined as follows: Elevation wasmeasured to the nearest 10 feet with a Thomuens pocket altimeter; aspect wasdetermined with a Silva compass corrected for declination; slope steepness wasmeasured with a Suunto inclinometer; landform type was classed as discussedabove; temperature was measured in degrees F with a Taylor thermometer andplaced in one of six temperature classes; windspeed was measured with a Dwyerhandheld anemometer and recorded in one of the four windspeed classes; cloud coverwas estimated to fall within one ,f four cloud cover classes ranging from clearto overcast; precipitation was subjectively measured as to type and rate; groundcondition was also subjectively measured and recorded in one of 7 classes rangingfrom dry to uniformly covered with snow; snow depth was measured and also placedin one of seven classes; snow condition was classed as wet, powder, packed,crusted or frozen; substrate was classed as bedrock, talus, rocky soil, ordeveloped soil. Biotic environmental factors were determined as follows:Cover types and habitat types were determined using criteria discussed above;conifer coverage was measured with a Lenmmon Model-C Forest Densiometer andrecorded in one of five coverage classes; conifer stem densities and basal areaswere determined through measurements with a Cruz-All Angle Gauge (Basal AreaFactor-lO) in conjunction with a Biltmore Stick for measuring conifer dBH classes.
With slight modifications, a computer program developed by the MontanaState Department of Natural Resou ces and Conservation was used to analyze andsummarize much of the habitat selection data.
Herd Health
To provide a general indication of animal condition, bighorn sheep fecalpellet groups were collected and analyzed for incidence and intensity of lung-worm (ProtostronEylus spp) infection. During the 1976-7" field season, a totalof 50 fecal pellet groups was collected. From 1 January 1977 through 31 December1978, 240 bighorn fecal pellet groups, consisting of 20 samples monthly for the12 month period were collected. All samples were sent to the Veterinary ResearchLaboratory, Montana State University, Bozeman and analyzed for lungworm larvaeusing the Baermann technique. Two yearling bighorns, illegally shot at SheepCreek on 24 October 1976, were retrieved and necropsy information collected. On4 and 16 January 1978 one adult ewe and one adult ram were found dead near Highway37 at Allen Gulch and Rocky Gorge, respectively. Vicera from the two yearlingsand whole carcasses for the adult ewe and adult ram were sent to Dr. D. Worleyat the Veterinary Research Laboratory for parasitological and pathological ex-sadnation.
Food Habit
In conjunction with collection of fecal pellet groups for parasite analysis,fecal pellets also provided determination of bighorn sheep food habits on amonthly basis for the calendar year 1976. Two pellets were randomly selectedfrom each of the 20 different pellet groups collected for a given month. Amonthly composite sample of 40 pellets was prepared for each of the twelve months.Composited samples were sent to the Composition Analysis Laboratory, Fort Collins,Colorado for determination and quantification of plant fragments through identifi-cation of plant epidermal tissue (Sparks and Malechek 1968). For each compositedsample, 10 microscope slides were prepared and 20 fields per slide, for a total of200 fields, were examined at lOOx under a binocular microscope to determine relative
-24-
• . : ., .. . . . -. ? . .], ,,- .. . .. - . , . - . . . . . . . . . . .. . . . . .. - . - . -
densities of plant fragments. Research by Dearden et al. (1975) has shown themicrohistoloL ;ai technique to be quite accurate in determining relative impor-.tance of food items in the diets of ungulates.
Rumen samples from two yearling bighorns were also examined for food habitinformation.
Population Dynamics
Bighorn sheep were classified as to age and sex whenever possible. Aneffort was made to classify ewes as adults or yearlings. Young-of-the-year wereclassified as lambs, with no distinction between the sexes. Whenever possible,rams were aged in the field through horn annuli counts (Geist 1966). These dataprovide information on present herd composition and give an indication of thepopulation trend from reproductive success and recruitment.
Deceased bighorns found in the field, were aged by horn annuli counts,sequence of incisor erruption, or by tooth sectioning and cementum layer counts.If possible, cause of mortality was determined.
Direct observations of s'ieep in the field were aided by the use of 6x30mm binoculars and a 15-60x variable spotting scope.
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. . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .
CHAF TER IV
RESULTS
Capture and Marking Techniques
Necessary field equipment (i.e telemetry apparatus) did not arrive untillate November 1976 which deferred trapping activities until 1 December 1976.From that date through 30 April 1977, 90 full or partial days were spent onthe sheep range attempting to capture bighorn sheep. With an almost completelack of snow on the study area, bighorns remained dispersed over their entirerange and did not concentrate on wintering areas. Total availability of naturalforage precluded sheep use of artificial baits at trapsites which renderedtrapping efforts completely unsuccessful. Although sheep were observed feedingand traveling in the vicinity of traps, they demonstrated no interest in eitherbait stations or salt blocks. In addition to trapping efforts, 13 attempts weremade to capture free-ranging sheep with immobilizing drugs. These attempts re-sulted in eight strikes, five misses, but only one successful capture. Four ramsand three ewes were struck with darts containing Sernylan at 100 mg/m concentra-tion and 1 adult ewe was strucl with a dart containing Rompun at 100 mg/mi con-centration. Sheep reaction to Sernylan varied from no noticeable response, mildataxia, to partial immobilization. Dart failure and a consequent incomplete in-jection of drug was recorded for the single dart containing Rompun. On 10 December1976, one ram, 5 1/2 years of age, was successfully immobilized with Sernylan andfitted with a radio-collar.
During the 1977-78 field season, trapping operations were reinstated on1 December 1977. As in the 1976-77 trapp'ng season, baited traps proved unsuc-cessful. However, one adult ram and one adult ewe were ( iptured at the wingeedrive trap established along Highway 37 at mile 36.6. Both animals were ear-tagged, instrumented with radio-collars and released. During winter 1978, threemore sheep consisting of one ram and two ewes from diverse portions of the sheeprange were immobilized with Rompun and equipped with radio transmitters. Oneadditional ram was drugged or. 1 September 1978 and fitted with a radio-collar.
During the course of the study, a total of seven bighorn sheep were cap-tured and radio-collared. Each marked study animal was assigned an alphabeticalprefix which corresponded with the chronological order of their capture (Figure12, Table 3).
None of the study animals were noticeably injured during the handlinC
process and there were no capture mortalities.
Distribution and Movements
During the course of the project, 206 relocations of marked study animalsprovided the basis for delineation of seasonal distribution and rovement patterns.Figures 13-19 demonstrate overall movements and corresponding dates of relocationsfor each of the seven study animals A through G. Site specific relocations areshown in Figure 20 a-h. Tables 4-10 list statistics for home range size, geo-graphic centers of activity, standard diameters, distances moved between consecu-tive relocations, and elevational ranges for each radioed bighorn sheep duringvarious seasonal periods. Seasonal key use areas for rams and ewes are shown inFigure 21 a-f.
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0) 0
Z 0 0 C0 -0
ICf) C~i Q)
0TI 8 0 :0
C)(1 CIO -'~
C/))
IU) j -I Q) a) a) Z-1 (1) (NJ N C) I
Ir ~ 71 r C
CDJ-z cz
FIGUJR- 21 a-f
Seasonal kpy ii !e arcas for shpsp on th'Ura 1-Tweed sheen ran -e
III-
-- 53
-c k
34 35
RAM -Winer p r i'.g
- - -
E N/
bS
R i',n g
*~~~~ vu' RA - it r pi
LJ C h
--------------------
LLLI
1 - c.7i
**-55
-, K / 00
''-4.
______ I
( (l
~~CIO
-- 56-
I I / -~ -~
4 o-~-
I' I '~7-"-- - -
I /i/p' j
1 K
/.r N-N-
/
/ 76- &-
- w w ~- ~ ~ - %% A 1 ------- , -
K17 - - -
~ r.~-~ __ U-oj-~ * -.- ~ - - - - - -
S -- ---
- --- ~-
- - ~1 -
-7
~-zZZ~Z§ % -- ~ ~ -4-
-~ -~E----.. ~
-57-
-1-.
C~j I
CNJ
S T- \
cr AV
NW
10 .00
-5v'
Aside from the rutting season, rams and ewes maintained relatively discretehome range tendencies during other seasons, Throughout most of the year, ramsconfined their range use to the Packrat Gulch-Sheep Mountain area south of TenmileCreek during the course of the project.
Rutting activit occurred from mid-November through mid-January, but ap-peared to reach peak intensity during early December. The rut for 1976 centeredalong State Highway 37, between Tenmile Creek and Peters Gulch. For unknownreasons, this area received little rutting activity during the 1977 and 1978seasons, while the Stone Hill-Sutton Creek vicinity served as rutting groundsduring both of these years. Ewe distribution during late fall-early winter ap-peared to differ between years and, as a consequence, dictated ram distributionduring that period. For example, rams that rutted near Sheep Creek in 1976, spentthe pre-rut period at Packrat Gulch in 1977, began moving north after 15 November1977, by-passed rutting grounds of the previous year, and traveled north to StoneHill where they remained throughout the rut. Rutting areas for 1976 and 1977were, therefore, separated by approximately 12 air miles.
Winter Range
Winter key use areas for rams were located in the following areas: 1)Packrat Gulch, 2) Volcour Gulch, 3) Sheep Mountain, 4)Rock Gut. Rams occupyingthe Packrat Gulch-Volcour Gulch ai ca were generally sedentary during wintermonths, but did occasionally travel east over the reservoir divide to SheepMountain where they spent short periods of time. Use of Sheep Mountain duringwinter 1976-77 may have been atypical due to the extremely mild winter conditionswhich allowed unrestricted mobility over the area. The 1977-78 winter periodmore nearly approached normal winter conditions on the sheep range and rams spentconsiderably less time on Sheep Mountain.
Important wintering areas for ewes were 1) McGuire Creek, 2) Stone Hillalong the bluffs between Sutton Creek Bridge and the big burn and 3) Falls Creekvicinity. At the end of the 1978 field season, ewes were again moving onto theStone Hill-Falls Creek area indicating traditional use of the area during winter.
Spring Range
During spring 1977 and 1978, rams used the Volcour Gulch-Packrat Gulch areaconsistently. In addition, Ram E spent early spring months at Rocky Gorge beforetraveling south to Packrat Gulch. Both Ram E and Ram C spent portions of latespring along the reservoir face between Sheep Creek and Tenmile Creek.
LAmbing
After maintaining distinct winter-early spring ranges at McGuire Creek andFalls Creek, respectively, Ewe B and Ewe D traveled south in late April 1978 toconverge at Allen Gulch where they remained through lambing and spring (Figure22). Ewe D and Ewe B gave birth to single lambs at Allen Gulch on 16 and 23 May1978, respectively. At least five additional ewes lambed and spent the post-partum period with their offspring at Allen Gulch, indicating the importance ofthis location as a lambing-nursery area. No other lambing areas were documentedduring this project.
-59-
IL
-r~-,
,F )I'. PRUMEN AALYE' CF 7VT LLEGAT.LY KTI-lDFTIFHFA. T rL)~F
AT 'EI RF= ON 24 OCTOFEF I97,
FOOD ZTF AP 7 F
EFS AlI D SFRVBC
A-m I o h ie r a '- n iA r t os-aphy: o2 ___
H od 4as e ;F dhs -ew l-7h "V1a-rh s a.-
noznderosa 1.Pleud2 s--ga me± 'F -'a
:raeE! be-u~i.
7 -'ndentlfieJ browc-e
-.C a~
ial.s~ eTreed rasprett~ dm
4 hi ~a n:?~f'-75-~
BLE 2b. PROTOSTRONGilID LARVAL DISCHARG3i, FOR IlRl TVIEED BIGHOE: Si-3E A:'DETEXL!E.D FROM 2-40 FECAL SANPIJS COLLECTED OM A MNhYSYDLBFIWEEN JANUARY AND DECDE3ER 1978.
SAMPLE NIUMBER NUMBER PERCENT NFJCi LARVAiNTHl~ SIZE NEGATIVE POSITI'VE POSITIVE DISCHARG:E
20 0 2010)"-.
20 1i9
20 2
21, 0 2 )
E-20 7
20 14
r. 20 51
nu L,1 24;, 3
Pf--r g:ram. dry fe-al maerial 0
-74-
FABLE 9.PROTOSTRONCYLID LRVA L DISI -HA.RGE FOE LTVTWEED EIGHORN 0iHEPF 1,SDET7-Y.CBD FROM4 50 FECAL SAIMPLES COLLECTED BEj-MEEU OCTOBER1 7AND) MARCH 1977.
aSKA"'LARVAL~ SA:MPLE NU1ABER NIUVIBEE PEPCT
DISCHARGE SIZE NEGATIVE POSITIVE PO cT =1E
5350 119 ~4r
a0
aPer zram dry fecal material
-73-
Protostron ls spp. However, neither had any extensive scarring or plaqueson the pleura. ind No. 2 (yearling female) yielded only the bronchiolar lungworm,P. rushi. Gastrointestinal worm burdens were very minimal compared with thosewe see occasionally from the Bison Range or Wildhorse Island sheep."
Results from fecal analyses for presence of lungworm larvae are summarizedin Tables 19 and 20. For the 50 samples collected during 1976-1977, 20 percentwere negative, 22 percent showed less than 1 larvae per gram feces, 32 percentshowed 1-5 larvae per gram feces, and 26 percent had more than 5 larvae per gramfeces. Mean larval output for all 50 samples was 5.3 larvae per gram. Meanlarval discharge for the 240 samples collected during 1978 was 9.5 larvae pergram, and the frequency distribution was as follows: less than 1 larvae pergram (LPG)-33 percent; 1-5 LPG-36 percent; 5-50 LPG-27 percent; 50-100 LPG-3percent; greater than 100 LPG-l percent.
For both sample collection periods, winter 1976-77 and calendar year 1978,lungworm infection rates for the herd were 80, and 85 percent, respectively.However, for all samples, intensity of infection was low to moderate. A seasonaltrend in larval discharge associated with stress periods for sheep is apparentfrom the data, with higher outputs of lungworm larvae occurring during winterand spring than during sumner and fall.
In addition to necropsy information, live-captured bighorns were thoroughly 7examined for ectoparasites. Ear mites, and lice were not noted on any of theanimals handled. However, winter ticks (Dermacentor albipictus) were commonon some of the animals examined, and were especially numerous in the neck andgenital regions of the body. On several occasions, fully engorged ticks werefound lying on the snow in and adjacent to sheep bed sites.
Food Habits
Rumen contents from two bighorn sheep collected as illegal-kills duringOctober 1976 are listed in Table 21. Grasses and grasslike plants, shrubs, forbs, . -
and bryophytes averaged 43, 43, 11 and 3 percent, respectively, for these twosamples.
Microhistological analysis of fecal material showed rough fescue (Festucascabrella) to be an important dietary component for bighorns during all seasonsof the year (Table 22). Sheep were not as consistent in their use of other bunchhabit graminoids as they were of rough fescue; however, Idaho fescue, bluebunchwheatgrass, Junegras, and needle-and-thread grass (Stipa comata) were commondietary constituents. There was a trend towards greater use o-f -shrubs and forbsin spring and early summer months, with a shift back to grasses in fall. Commonwinter browse included, serviceberry, Douglas-fir, ceanothus, (Ceanothus spp),.oceanapray, nowberry, and bitterbrush. On an annual basis, grasses and grasslikeplants, browse, and forbs constituted 64.20, 29.96 and 5.74 percent of the diet,respectively.
Population Dynamics
Interpretation of population status and trend through analyses of temporalchanges in primary age ratios (ewe:lamb ratios) has little meaning when workingwith a very small total population number, such as is the case with the Ural-Tweed herd. To provide better assessment of the actual population dynamics of
-72-
_S
TABLE 3).RESULTS OF El.KDOPARASITE AINALYSIE OF" FIVE p 7CHOFURJT' SIHfF (AFASFOLUhT Oi. THE UFJ.J-TWEED STUDY AR~EA.
CAUSE DATE OF 17OFC PAIIESEX AGE OF DEATH COLLECTION SPECIES No. LCAI7
21/2 Vehicle 1112)"'"4 Marshallai-ia 290 O .
ri.ars ha lli
Prcotostrono~yluw Lx,-:stilesci
P. rusru 2 ---
T. marshal--,- 241 A-:.
1 1/2 1le,-a1K i 1O/2+ 'Y P . ah:
I 1 4~K P. ruh z 1
1.'. marst~a] 7 i ....
V e e2VLK 1/1&/7t& P. ru h,-
E. rnar naIL ..
Wy' ri:, e,
TABLE 17. ANALYSES OF TIMBER S'IAND CHARACTEiSLZICS ON SIES SELETED iYBIGF iJ SiEEP ON THE URAL-TWEED SHEEi RALGE.
TP3FSTA ND IVR1T'EF?'
BASALb TREES SAJ.: LE,CANOPYa AREA DB1 PER AIREH SIZE
MONTH X 7 x
Jan. 16.2 46.4 ,. .
Feb, 14.2 22.2 2 .0
Mar. 1 2t c- 1.
Ar. 29.4 1. c.O
Ma-; 45.8 Ci,. , . .
June 22.7 -0.0 20.2
July 30,0 . 24. F 2
Aug 52.0 68.0 21.0 52. E
Sep . 35.0 7.0 l 7 ."
0t '*37.5 80.0 :0.6
De. 15.0 37.5 20. -,
Anual 2E.( 54.4
& Car,: v- - percent conifer crovn ,.osue
b Square feet of conifer basal area per a:rrc
Conifer diameter at breast heighth (dEBH) ine s.ire.i nt ,
-70-
TABLE 16. MONT1,Y BIGNORMN SlEP USE OF ELE'vA TIN AND SLOPE ON TiE: ITRA!L-7WVEELSHEFlD -LNGE.
JAN. FEP. MAER. APR. MAY 11777 JU'LY AUG. S'-EPT:. OCq. --'E' I .
x 3256 34r)9 4059 357-7 4120 4-1:,,- 4 277 4515 -3350 4(C,02 7>aE
LS 490) 41 492 645 41~ F 1 7 1 2,(, 7EV vj. 2780 2800 3200 2560 -500( 27,,K --44 0 2-0 (D0 Z.:2 27,cjAT mAj( 4800 4350 5080 4600 4;c #4) Q 58 4)99 444 4a
0 SANP.
N SIZE 5- 29 2~ E ? 1 2 S
X 34.o 50. - 3,7 34. 35.1 31.L: 9'3. .
S 7.1 C; .8 4 5.> .5 5. 7. .
Mi,.25 5 23 25 27 25 2F
P J 58 58, 59 40 5 2 7 4 3
E
SIZ:E Y, 2 27 7 P 1 2 7 1
E'rva-i-r meaS-irei irn f e
t -
7 irnea. ured in. de -ree:
-69-
TFABLE 14. MONTHLY BIGHORN SHEE' USE OF VARIOUS LANDFO< TYPES DESCRITEL FO,-THE qr.DY AREA
LAIDFORBI TYPEMONIH BROKEN BLUFF HILL CLIFF TALUS i D E
a b17/57 4/1 3 5/17 2/,.
Fe t. 9/31 a 4/4 / /.
Mar. 12/43_ 5/18 5,/1'- 3, /a
A;r. 7/39 1/ 3 -/ " .
I-: E/4- 7/'41 -
15/65 2/9 ,/-
A,,r. 4/44 - -, "
2,11- 00
9/50 3//i7 4122 2,/ 1
3/100
De' 6/55 3,127 2 ,/1"
AiL':i.al 9/S 3(/l7 0/ -"
a r& L er of relo2a:iors
Per-e:-age of tc.al duriin he mrn -c
Per,.entage of arnnal t ta]
-67-
below cliff complexes served as convenient foraging areas. Table 14 listsbighorn sheep use of the various landform types described for the study area.
Microsite
With respect to aspect, slope and elevation, Tables 15 and 16 show big-horn sheep selection of these various parameters on a monthly basis. Collectively,south, southwest, and west exposures received 89 percent of all bighorn sheep useannually, and appeared to be the predominant aspects of sheep occupation duringall seasonal periods. Very few radioed-sheep observations were made on northerlyaspects (3 percent) and probably reflect transient individuals traveling from onekey use area to another. Radioed sheep were consistent in their selection ofoversteepened terrain during all seasons. Average slope steepness for sites usedby sheep throughout the year was 34.4 degrees, and mean values for each monthranged between 30.0 and 39.1. As might be expected, there appeared to be a trendin sheep utilization of different elevational zones during various seasons, withgreatest use occurring at lower elevations during winter months and higher eleva-tions during late suimmer-fall months. Sheep tended to be at higher elevations(above 4200 feet) near the top of the reservoir escarpment during October andNovember just prior to the rut. During the rut and early winter months ofDecember, January and February, most sheep activity occurred below 3500 feet,but some use of higher elevation habitats was not uncommon.
Timber stand characteristics for 98 sheep occupation sites are displayedin Table 17. Two species of conifers, ponderosa pine and Douglas-fir dominatedall sites examined, while Western larch (Larix occidentalis), aspen (Populustremuloides), and lodgepole pine (Pinus contta), were present on 3, 2, and 1plots, respectively. Conifer canopy coverage values :anged from 0 (opening) to100 percent (closed canopy), but averaged only 28.6 percent for all sites ex-amined, reflecting higher sheep use of open forested areas. Conifer stem densi-ties (trees/acre) ranged from 0 (openings) to 260, but Lveraged annually, 51.4trees per acre, again demonstrating bighorn preference for more open cover typeson the Ural-Tweed range. Mean DBH values reflected a preponderance of largerdiameter class trees on all sites, for each month (range 14.7-24.8 inches) andannually (i = 20.0). However, nearly all diameter classes ranging from 4" Douglas-fir saplings to 46" ponderosa pine and 54" Douglas-fir were found on some of theplots. Sheep occupation of sites showing increased stem densities during Septemberand October may indicate a preference for these sites for their thermal coverattributes or may be a factor of the small sample sizes for these two months.
Observations of sheep bedding-resting situations showed an obvious tendencyfor bighorns to select sites immediately adjacent to large diameter ponderosa pineand/or Douglas-fir trees located along the rims of bluffs, cliffs or rock outcrops.
Herd Health
Results of parasite analysis for five bighorn sheep carcasses collectedon the Ural-Tweed sheep range are summarized in Table 18. Of the five carcassesnecropsied, all were positive for Protstronylus app. (lungworm), either thebronchiolar lungworm P. rushi or the parenchymal lungworm P. stilesi or both,but showed little siai? ofr-cessive buildup of either of hese lUngworms. Allcarcasses were found to be only lightly burdened with gastrointestinal worms.In his examination of the two illegally shot yearlings, Dr. D. Worley of theVeterinary Research Laboratory at Bozeman commented that "neither animal showedevidence of a buildup of internal parasites, although both were infected with
-66-
"." - " - ', "' " " " , " -" " ":- " ° -"" "" " - ' " " -': ' ' -" " "- . . . ' .. . " i' " "- " " " " "'. -
TABIE 1-5. MONTHLY BIGHORN SHEEP USE OF VAR.P:T7 HABITA' TYPES ONh THE IRAL-TWEED SHEEP RANGE
HAEIrITA? TYPE 0MONTH PSME,/CARU PSlE,/ARUV PSl.'SYAL PSIM, PHIiA PS:: , L7
a b
Jan. a2/7b -,4/47 14/47
Feb. 9/31 9 ,'7 1' ,
Mar. 12/43 1/4 10/36 3/11/
A, r. 9/50 2/12 7/3,
May 3/1i 12/71 2/11
Ji-ire 6/26 2/7 /35 , .
J ul y 10/56 /'22 3/17 ,
Aug. 7/78 2'22
Sept. 2/100
Ct. 9/50 6/33 3/17
r'vv. 1/33 1/75 1/33
D.. 1/? 7/64
Ar u a 67,/33 1,/ 72/35 48'23 ).2, -.21~~ -7 F/2-
S e: a,-e .f rel, --a! n during the n.,,.'.th
Pex.entage of re: cations during the yea.'
-65-
.. . . .-.
TABLE 12. MONT}HB HW' SHEEP U-SE ('F %'AFTr-)I2 VEGE7ATIOT' lV~ ~DESCRTBED ON THES STIDY AREA-
MON~hROCKL.AN!D SHRUB-GRASS FAF? PRB: QR'
a, b
-~ a. /2?
AnMa 7: 2),2"
Jrce-,g 6,f2 -n-ul t
0,' q' ,-64-
Habitat Selection
To ins. a unbiased data on habitat selection, only telemetry relocationswere used to assess characteristics of sites being selected by Ural-Tweed big-horns. Radio-collared sheep permitted relocation of these animals in both openand timbered cover types, whereas random observations of sheep were biased towardopenings, mostly adjacent to Highway 37. Habitat site selection data were pooledfor each month during different years. However, most data came from the 1978calendar year.
Cover Types
Of the five major cover types designated on the study area, only four wereof importance to bighorns (Table 12). None of the radio "fixes" occurred on thetrue shrub-grass cover type (i.e. bitterbrush-rough fescue area near mouth ofSutton Creek). However, this cover type has a very limited distribution andcoverage on the sheep range. Conversely, the closed forest cover type has ex-tensive coverage on the area but received relatively light use. Most radio"fixes" on the closed forest cover type were thought to be animals in transit
as these sites showed little sign of continual sheep use. Although parks accountedfor only six percent annual use by sheep, this cover type was of particular im-portance to rams during spring and summer months, especially near Packrat Gulch
*and on Sheep Mountain. Rockland types were of importance to sheep during allperiods of the year in that bighorns tended to bed along rims or at the base ofcliff faces, and also on talus slides.
Habitat Types
Of 19 habitat types delineated on the sheep range, only 5 of the driesttypes appeared to receive 100 percent of the sheep use Table 13). In order ofapparent decreasing importance, these habitat types were- 1) PSME/SYAL, 2)PSME/CARU, 3) PSME/PHMA, 4) PSME/ARUV and 5) PSME/LIBO. The Douglas-fir/snow-berry (PSME/SYAL) and Doulas-fir/ninebark (PSME/PHMA) types received greatestsheep use during winter months, while PSME/CARU (Douglas-fir/pinegrass) becameincreasingly important during spring, summer and fall.
Many of the relocation sites were individually habitat typed to phase andgenerally were of the drier phases within a type. For example, most of the PSME/PHMA and PSME/SYAL types were of th CARU phase, while the true PSME/CARU typeusually fell into the AGSP (Agropyo spicatum)phase. In addition to the xeric
* and rocky nature of these sites, another common denominator was the presence ofbunch grasses, i.e. bluebunch wheatgrass, Idaho fescue, rough fescue, Junegrassand purple reedgrass.
Landform Types
Sheep use of the broken landform type was consistent throughout all monthsof the year, but may only reflect the fact that this type predominated along thereservoir escarpment where bighorns spent nearly all of their time. Forty-eightpercent of all radio locations were on this type. Bluffs were of some importanceto sheep during winter months, as evidenced by Ewe D's use of the terraced terrainalong Highway 37 between Sutton Creek and Highway MP 50.0 during January, Februaryand March 1978. Again cliff faces and talus slides were of primary significanceas resting and bedding areas during most seasons, while broken and sidehill terrain
-63-
• . . .°S+. + . • .+ . , + + . . -.. o : - + .+ . . . i .-. . . ' - : L .
. " • " - .. .T .U % .. . _ = . +. . -" - . . :+ . ",, .. -_ . .,,. _ * ," ' -.. ,I. -.- -....- " -- *-- -- - X+- - ,- ' - + " .
00
,-~ -4
-1 (I.. g7 r.2 rl, ' - ( . C. % : .
~ C N f Cj - 'U ('U 0.
C)
(79 N> '2 - ' >
o rrNC K -) C-, CMI- r
0 N T
C)- C-
COf > 0-4 E-4 C(> CA- c-
-62
Summer Rang
Except jr the rutting season, bighorns traveled more frequently duringsummer months than during other time periods. Exploitation of certain key use
a areas separated by intermittent travel between these areas characterized sheepmovement patterns during summer.
Rams utilized areas south of Tenmile Creek exclusively during the latesummer period. Sheep Mountain was the most important summering area, withPackrat Gulch being of secondary importance to rams during this season.
Ewes concentrated their activities on certain key sites between TenmileCreek and Rocky Gorge, with the south slope overlooking Tweed Creek assumingsecondary importance during late summer months. The late summer period wasalso the only time ewes used the area below and west of Ellsworth Mountain.Similar to rams, ewes made intermittent excursions between key use areas.
Fall Range
Approximately one month preceding the rut, rams moved from the SheepMountain summer range to occupy Packrat Gulch before moving north for thebreeding season. Ewes appeared to remain in the same general vicinity theyused during the summer, then began a gradual movement north towards McGuireCreek and Stone Hill. Observations of mature rams with ewe-juvenile groupsat Allan Gulch, Tweed Creek, Peck Gulch and eventually Stone Hill marked thenorthward progression of all age and sex classes of sheep during the late fall-early winter rutting period.
Range use patterns of Ural-Tweed bighorn sheep do not facilitate designa-tion of discrete and exclusive classical qeasonal ranger since these sheepdemonstrate recurrent use of certain key area during all seasons of the year.Figure 21 reflects only the predominant and most important seasons of use on agiven area and does not necessarily preclude use of the area by either rams orewes during a season not listed. Table 11 lists the monthly spatial and temporaldistribution of the 206 radio relocations plotted during the study and providess~ne insight into the recurrent use and relative importance of key use sites onan annual basis.
Bighorns were observed using areas in close proximity to Highway 37 whentraveling from one end of the sheep range to the other end. This was especiallyevident during the fall and early winter period when sheep were traveling longdistances during the rut. Certain sections of Highway 37 served as common cros-singareas for sheep. Bighorns were observed above, below and on the highway alongthese sections and made frequent crossings at the following highway mileage points;35.9, 36.5, 36.6, 37.0, 37.4, 38.0 (Teamile Creek-Rock Gut section); 42.0 (TweedCreek section); 48.5 (Sutton Creek section); 49.9, 50.5, 51.0, and 52.0 (Stone
* Hill section). Rams moving to and from the rutting areas north of Tenmile Creekcross Highway 37 at mile post 34.0 at the south end of the Tenmile Creek Bridge.This is the same site at which an adult ewe was killed by a vehicle shortly afterthe highway officially opened in November 1974, and appears to be an important
" sheep crossing. Sheep crossing Sutton Creek usually do so at or near the SuttonCreek Bridge, and frequently cross the highway to travel under the bridge when
Smoving onto Stone Hill. Rams using the Packrat Gulch-Volcour Gulch area duringspring occasionally crossed the pavement to forage below the highway, but theircrossing points were inconsistent due to ease of access along this section of
-- Highway 37.-61-
Fe L
('-j LC> N
- C
* u II? ~~r-i f'C t'L
C .
r, UH
ifC -, (-V('I '.
a4 -'"-0"7
L4v
SM
Cf ->Cl
C/'.
* ~ ~ ~ ~ U U' Q)C - U 1- '
('- ---- c'. (D Ok co c-E-i
C)I C, c~ ~ ~
CfCM
CM - C'- C-i) 0 F>
0 * *
C'IL
Cy, - < -T
-z CIO N -
CiC)
* ,-,KCMON N>C- c0 --
-c- -4C1 ONI cli\ -- r-- _c'qC
W c Z a)'0 O F'JL4 (NJ 't C;
(04 c CC a)A 0r- (NJ U
4 L V)>W co
ca 02 U) 0 M CFzU I aa CP .a,4 .a4Rxc - >0
C) G)
0O0'
0 C\,-
C()
o CC)
cc,
C)
"0
00r
i o 0 . -1
~-78
this herd, the "cohort completion" total count method described and used bySmith (1976) for Rocky Mlountain Goats was utilized on this study. Briefly,all sheep which could be accurately classified were placed in the appropriateage/sex class (cohort) as follows: Ramns were classified into one of 8 age--classes ranging from 1 year to 8 years of age; ewes were classified as yearlinsor adults, because of the difficulty of aging ewes in the field; young-of-the-year were classed as lambs, with no sex distinction being made. For a giventime period, a population estimate was calculated by totaling the maximum numberof individuals from the various cohorts. Adequate sample sizes were not alwaysobtainable for each month of the study, no three month periods were combined tocorrespond with seasonal periods of the year (Table 23).0
During December 1976, a total of 7 known age rams were observed on the rut-ting grounds near Sheep Creek. Of these seven, two were yearlings and one wasa two-year old. They were not active in the rut. The other four breeding classrams consisted of one each 3 1/2-year old, 4 1/2-year old, 5 1/2-year old, and 61/2-year old. Early in December, the 3 1/2-year old ram and the 5 1/2-year old 0ram were observed with a band of ewes near Rock Gut. The following day, evidenceof an illegal sheep kill was discovered In the exact spot where these sheep wereobserved the previous day. The 3 1/2-year old ram was never seen again and pre-sumably was the victim of the poaching incident. During the next several months,the two yearling rams and the four rams older than two years were accounted for.On 10 December 1976, the 5 1/2-yeao- old ram was captured and instrumented witha transmitter collar. On all visual contacts with this ram, from 24 February1977 through 26 April 1977, and again from June 1977 through October 1977, hewas accompanied by three additional rams which by their age and general appear-ance seemed to be the same individuals observed during the rut. During the earlyrutting period December 1977, these same rams were observed on Stone Hill, par-ticipating in breeding activities. In January 1978, two of the breeding classrams were removed from the population. The radio-collared ram (the 6 1/2-yearold ram) was killed by a vehicle near Rocky Gorge, and t~e 5 1/2-year old ramzwas killed by a lion at Rock Gut on 8 January. There remained only two olderage class rams in the population. On 17 January 1978, the 3 1/2-year old ramwas radioed on Stone Hill, and the 7 1/2-year old was collared on 29 January nearSheep Creek. Subsequently, these two rams joined each other and began using thesame areas they frequented the preceding year when the two other, now deceased,rams were traveling with them. No other older rams were observed during 1978.Suspicions that these were the only two breeding class rams remaining in the herdwas confirmed, when both of these individuals were observed together with bothradio-collared ewes, and the recently collared 2 1/2-year old ram near AllenGulch on 3 January 1979.
Demographic data collected on the ewe-juvenile portion of the herd impliesa very small but widely dispersed reproductive population segment. For example,of the three adult ewes radioed at diverse locations on the sheep range duringJwaiary and February 1978, only two survived the winter. The two surviving eweswintered in different locations, but merged at Allen Gulch to lamb and rear theiroffspring. They then continued their association throughout suzmer and fall 1978.
During June 1978, a total of seven ewes including the two marked ewes, andseven lambs were observed at Allen Gulch, and were thought to represent the grossprimary production for the herd, as no other lambing areas were discovered. Again,in August seven ewes including Ewe B and Ewe D and seven lambs were observed atRock Gut. By early fall, and also during the 1978-1979 rutting period, only fivelambs could be accounted for, indicating late sumer-fall lamb mortalities.
-79-
TABLE 23. POPULATION ESTIMIATES FOR URAL-T4EED HRUSING A COHORT1 Cofli1 1,EL -TOTfiT CL-'T ME2THOD
PERIOD IlYr 2 7 2 v. 'f
12/1/'
127 2
2-2
2 2 - o
-11/9/78 2 2 1952
-13/9 2 2 '7
a wd~x f thi-s ram ben-i~a> ilederyir Decefr-er
-I~ear -,Id ram 1k1X ed by, mcurtain alin cr.n January 19c)
1- ear old rad'- -11iared ram k*lle-d by vehicle ini mid-January
-p0-
The 3 January 1979 observation of a single group of 18 sheep, consistingof two yearling rams, two 2-year old rams, one 4 1/2-year old ram, one 8 1/2-year old ram, seven adult ewes and five lambs, included all five marked sheepthen present in the population, and would suggest that number to be the totalpopulation based on a simple Lincoln Index calculation. The possibility of afew sheep being detached from this main band is not, however, discounted. None-theless, a very mall herd size of probably no more than 25 animals is the in-escapable conclusion.
Sheep mortalities on the Ural-Tweed range were divided into two categories1) natural and 2) man-caused. During the course of the project, eight bighornsheep were known to have died on the study area. Three of these deaths wereattributed to natural causes, while humans were responsible for direct removalof the other five sheep. Subsequent to the opening of State High 37, in November1974, and prior to initiation of the sheep study, four additional sheep were knownto have been removed from the herd through human causes. Other mortalities were,no doubt, occurring, but were not discovered during the study.
Human Caused Mortalities
Shortly after State Highway 37 officially opened, in November 1974, oneadult ewe was struck by a vehicle and killed at Tenmile Creek (MP 34.0). Thecarcass was retrieved for necropsy information. During the same month, theremains of two illegally killed ewes were found on Stone Hill. On 2 March 1976,one adult eve was killed by a vehicle while crossing Highway 37 at highway mile50.6, Stone Hill. Coyotes had consumed nearly the entire carcass before it couldbe located.
On 24 October 1976, one yearling ram and one yearling ewe were illegallyshot and left along Highway 37 at Sheep Creek.* Both carcasses were recoveredand examined. On 2 December 1976, evidence of an illegal sheep kill was foundalong Highway 37 at highway mile 38.3, near Rock Gut. A band of nine sheep,including two rams, was observed there the previous day. A local truck driverreported colliding with an adult ram on the highway between MP 38.0 and 39.0, nearPeters Gulch, on 5 October 1977. Although the animal was badly injured and bleed-ing, the trucker could not capture it. Two days spent in the area attemptingto find the ram were fruitless, and this animal presumably died of its injuries.Radio-collared Ram A was found deceased, just above the highway at MP 40.0 near -
Rocky Gorge on 16 January 1978. His left foreleg and shoulder region was badlyfractured as a result of a vehicle collision. The carcass, although emaciated,had not been fed upon by scavengers and was otherwise intact (Figure 23).
Natural Mortalities
Only three carcasses discovered on the sheep range were attributed to naturalcauses. One old ewe (12 years plus) was found lying along the highway guardrailat MP 39.0 on 4 January 1978. The State Highway Department snow removal crew hadobserved this animal there the previous evening and reported that she was havingconsiderable difficulty in her attempts at crossing over the guardrail. Therewas no evidence that ahe had been struck by a vehicle but her generally poor andemaciated condition suggested death through debilitation and subsequent starvation.The radioed ewe, F, was found dead up Sheep Creek in April. She was thought tohave died a natural death over winter.
S
S
0
S
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w
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-.. . . . .
The only evidence of a predator-killed sheep was the 5 1/2-year old bighornram taken by a large male mountain lion (Felis concolor) on 8 January 1978 atRock Gut Brioie (Figure 23). The kill was made approximately 50 yards east ofthe Rock Out Bridge on Highway 37. The predator covered the carcass betweenfeeding sessions for the next three days, before it was killed by the client ofa local outfitter.
-83-
. . . . . .. - . . . . . . . . . . . . . . . . . . . ..
CHAPTER V
DISCUSSION AND CONCLUSIONS
Capture and Marking Techniques
Capture and marking of free-ranging bighorn sheep was of critical con-sideration on this project. Contract stipulation required six bighorns fromdiverse portions of their range be instrumented with telemetry collars and tothis end a total of seven sheep were eventually radio-collared. This aspectof the project was not only important to satisfying contract requirements, butwas also imperative to overall success of the study. An extensive literaturereview was made to determine appropriate alternative methods for capturingbighorns. However, circumstances on the Ural-Tweed sheep range dictated eventualcapture methods. Clover traps were successfully used to capture bighorn sheepin ColoradG. (Moser 1962) and Montana (Brown 1974), but proved to be an unproductivemethod in Idaho (Morgan 1970) and on this study. A variety of trapping techniques,ranging from foot snares (Aldous 1958), live neck-snares (Mosaman et al. 1963),manually operated drop-nets (Erickson 1970) to portable corral traps (Tilton1977) were explored for possible application on this project. Many of theseoptions were discarded because either suitable areas for trap construction werenot available or the techniques may have caused unnecessary injury to the animal.Immuobilizing drugs were used as a last resort. Sernylan (phencyclidine hydro-chloride) used effectively on Canadian bighorns (Stelfox 1976) proved unsatisfac-tory on this study. A change to Rompun (xylazine), a sedative and analgesic drug,during the 1978 field season provided consistently favorable results for cap-turing Ural-Tweed bighorns. Other investigators, (Stewart and Stoneberg pers.comm!.) also found Rompun to be a suitable drug for use on bighorns in other areasof Montana. Although the number of animals drugged with Rompun was small, adosage application of 300 mg. would appear to be suitabl-_ for adult sheep ofboth sexes.
In some respects, performance of telemetry equipment was disappointing.Although designed for two years operation, some of the radio transmitters failedafter only several months of use. Were it not for the fact that study animalscarrying inoperative collars were in continual association with other collaredanimals wearing functional transmitters, relocation of the former animals wouldhave been on a random basis, at best.
Distribution and Movements
Various investigators, Blood (1963), Geist (1971), Erickson (1972), andBrown (1974) documented herd segmentation within populations of mountain sheep;herd units or subpopulations occupied discrete home ranges which were in closeproximity, but interchange between segments did not occur or was minimal despiteabsence of major restrictive physical barriers. Geist (1971 80-81) explains thisphenomenon as a function of the high degree of home range fidelity demonstratedby mountain sheep. He also suggested that distinct home-range groups are moretypical of female sheep than for rams. Rams were moms mobile and mingled withdifferent ewe home-range groups, particularly during the rut.
During this investigation on the Ural-Tweed herd, these phenomena werefound to be only partially true. Original speculation that the entire herd was
_84 -
contiguous, was confirmed. For instance, ewe-juvenile groups utilizing StoneHill and McGuire Creek during winter mingled with each other and were the sameanimals observed using the Sheep Creek-Tenznile Creek vicinity during otherseasons of the year. There were, therefore, no discrete ewe subunits in thepopulation. Findings on this study showed herd segentation to be a seasonalphenomenon and then only with respect to the sexes. While all ewes confinedtheir range use to areas north of Tenmile Creek, rams tended to remain southof Tenmile Creek during most of the year. During the rut, however, the entireherd became a single unit.
Rutting Areas
The rutting ground above Ural was historically documented (Ensign 1937,Brink 1941). Reasons for bighorns changing rutting areas on the Ural-Tweedrange between consecutive years of the present study are not clearly under-stood. However, speculation as to the reasons is forwarded in an attempt toprovide some insight into the current situation. Ram distribution during thebreeding season is obviously a function of ewe distribution. Ewe-juvenilegroups, which normally spent the summer-fall period near Ural, appeared on theStone Hill-Sutton Creek area earlier during the 1977 season than they did during1976. A controlled burn for wildlife was conducted near the mouth of SuttonCreek by the U.S. Forest Servi .e during spring 1977, and may have caused Sheepto: 1) remain in that area summer and fall or 2) accelerate their return tothe area after summering near Ural. As no ewes were radio-collared during thattime period, neither of these assumptions could be verified. However, verylittle sheep sign was found near Ural during December 1977, and the one radioedram by-passed this area on his way to Stone Hill where he and other rams rutted.Weather patterns were entirely different between the two rutting seasons. In1976 there was literally no snow on the sheep range, whereas the 1977 season wascharacterized by early snow cover over th-, area. This m~ay have caused ewesto move onto winter range earlier than the previous year. High-speed vehicletraffic on Highway 37 in conjunction with trapping and darting activities on therutting area may have caused sheep to avoid this area during the succeeding rut.Desertion of suitable habitat through human disturbance has been documented byGeist (1971) for mountain sheep.
Winter Range
Ural-Tweed sheep remained comparatively mobile on the winter range, withrams having larger hc-:,me ranges and standard diameters than ewes. Similar findingswere reported by Morgan in Idaho (1970) and Brown (1974) in Montana. However,during a severe winter Erickson (1972) working with bighorns ir. the Sun River areaof Montana found rams had moved less than ewes and both sexes showed small standarddiameters compared to those found on this study. Winter standard diameters andhome range size may only reflect weather conditions or may be related to factorsintrinsic in different populations. More frequent travel and larger home rangesfor wintering Ural-Tweed bighorns probably functions as a resource strategy whichpromotes dispersed use of small areas of primary sheep habitat separated by areasof marginal or non-sheep habitat.
Spring Range
In contrast to other bighorn sheep herds in Northwestern Montana, Ural-
Tweed sheep demonstrated no distinct low elevation spring concentration areas.
Sheep in the Thompson Falls and Kootenai Falls herds characteristically capi-talize on the soring "green-up" by moving down onto the river terraces duringMarch and Api.Ll. In contrast, Ural-Tweed sheep actually showed increased use ofhigher elevations immediately following the winter period. Old reports andinterviews with longtime residents provided historical perspective on thisaspect of Ural-Tweed sheep range use. Historical use of the Kootenai Riverflood plain by bighorns is well documented. Old residents formerly occupyinghomesteads along the Kootenai River between Fivemile Creek and Sutton Creekrecall having mountain sheep in their fields prior to clearing of the reservoirimpoundment area. Bighorn sheep remains were found along the old Great NorthernRailroad track traversing the Kootenai River terrace between Rexford and Warlandsiding. With clearing of the Libby Reservoir impoundment and subsequent floodingof the area, the critical late winter-spring range at the base of the reservoirescarpment was inundated and irretrievably lost as spring habitat for mountainsheep as well as other ungulates.
The importance of spring range to the long-term well being of a sheeppopulation is documented in the literature. Speaking of mountain sheep inCanadian Parks, Stelfox (1976;29) concluded that:
"Valley-bottoms and low-elevation south-facing slopes are evidentlyimportant to sheep in late pregnancy, and they influence lamb produc-tion and survival because t'-. are the first areas to green-up and providethe high protein forage necessary during late-pregnancy and early lactation."
If spring green-up is retarded or spring range has been lost, as is the situationon the Ural-Tweed range, ewes must sustain themselves on dormant winter foragewhich is lower in total nutrient content, especially protein, and less palatablethan succulent new green forage. Geist (1971) suggests that early postnatalsurvival of lambs is a function of ewe nttrition during late gestation and thelactation period. Lack of a high protein diet during la~e pregnancy is generallyreflected by low reproductive rates and subsequent increased lamb mortality(Hebert 1973). Ewes on the present study, after wintering on a maintenance diet,must forego optimum spring range conditions and enter late gestation in a nutri-tional deficit. This deficit is maintained through the lactation period and intosummer months, and is apparently carried over to the fall period as evidenced bythe less than thrifty appearance of these animals during autumn, at a time whenbody condition should be optimum. The ramifications of these conditions foranimals going into winter are obvious.
Lambing
The lambing area at Allen Gulch was used intensively by ewes several weeksbefore and after parturition which peaked around 20 May 1978. The laxnbinr periodappears fairly synchronous for Northwestern Montana sheep herds. However, new -born lambs have been observed as early as late April (Matthews 1973) and earlyMay (Brown 1974, Joslin 1978) on some of the ranges. In other Montana regions,lambing does not occur until late June (Stewart pers. comms.).
The Allen Gulch area was the only lambing ground located during this inves-tigation. During spring 1941 Brink (1941) documented lambing areas at U~ral and
7.S
Sheep Creek. Original concern that these areas would be abandoned as lamnbinggrounds due to th"eir proximity to Highway 3Y appears to have been warranted.There was no evidence of lambing on these areas during this study. However,these sites were used by nursery bands during summer and fall, indicating that -
they have not been deserted during other seasons.
Susmmer Range
During summer months, rain and ewe bands remained separated on respectivesummer ranges. Similar findings w.ere reported by Wolf et al. (1970) for Yellow-stone Park sheep. Smith (1954), Sugden (1961), and Wolf et al. (1970) foundboth migratory and non-migratory sheep within their different study areas, andsome sheep reportedly moved up to 40 miles between distinct winter and summerranges (Smith 1954). These authors indicated that once on summer range, bighornsmove very little. These observations were generally not true of Ural-Tweed sheep.True migrations were not noted for these sheep in that movements between seasonalkey use areas usually involved only changes in elevation and/or lateral shiftsalong the reservoir face. Study animals on the Ural-Tweed range also moved fre-quently during summer. Similar findings were reported by Brown (1974, for sheepin the Thompson Falls region of Northwestern Montana.
Fall Range
Early fall distribution of Ural-Tweed sheep was indistinct from theirsummer distribution. Sheep were generally at their highest elevation zone duringearly autumn, but dropped to lower areas near the highway during late fall or therutting period. Inclement weather on summer range was thougit to be the influencingfactor for sheep to move from summer to winter range in some studies, (Smith1954, Blood 1963, Erickson 1972), but was not the case in the presunt investiga-tion. Even during the 1976-77 winter, wl ,n there was literally no snow on thesheep range, bighorns still descended during the fall ruw to utilize areas atlower elevations. A cooling trend in the weather along with fall moisture may havemade lower slopes more habitable than they were during hot summer months. Thedescent and gradual drift onto wintering areas seems to be the characteristicpattern of movements for these sheep.
Sheep were in closer pro;.imity to and made more frequent crossings of Hirh-way 37 during fall rutting activities than during any other time period. Along -
certain sections of the highway, sh~..ep had considerable difficulty in achievinga successful crossing of the roadway. Physical features of the highway requirethat sheep cross at very specific points, as areas between these sites are sheervertical walls which were blasted out during highway construction (Figure 24).Bighorns are unable to negotiate these vertical cuts which range in height from20 to over 100 feet. This situation causes problems as sheep moving from foragingareas below the highway must travel along the roadway for several hundred yardsto reach access points to upalope security areas. The highway section immediatelysouth of Sheep Creek, an area of heavy sheep use, exemplified these circumstances.Between highway mile 36.6 and 37.4 there is only one point, MP 37.0, at whichsheep are capable of climbing the highway rock cut, and then it is done only withsome difficulty. As a consequence, sheep normally traveled along- the highway guardrail or on the pavement to cross the highway at either Mile 36.6 or 37.4. Out-sloping of these bedrock cuts would greatly facilitate sheep access to foragingand security areas below and above the highway. The amount of time spent on theroadway by these animals would be lessened, thereby reducing the potential for asheep-vehicle collision.
.7 -7
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.cc
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PN coCL
ra,(3
.5SI~*~ .. c )
itat Selection
Ural-Tweed bighorns were consistent in their use of steeper more broken-tions of their range. There was little indication of sheep use above the reser-.r escarpment. Since there are no true grasslands available to sheep on theLl-Tweed range, these bighorns have been relegated to the escarpments which . -
icurs with the statement that "sheep remain almost exclusively on grasslandsI rocky escarpments throughout the year" (Stelfox 1976).
Grassy openings, coniferoub canopy coverage (circa 30%), large diameteriss ponderosa pine and Douglas-fir (circa 20" dBH), and relatively low stemisities (<50 trees/acre) characterized the cover types most frequently usedbighorns.0 South, southwest, and west exposed broken and bluff terrain in:ess of 30 slope steepness received the greatest amount of sheep use. Rock.crops, cliffs and talus slides were important to bighorns as bedding and:urity areas. In addition to scree, the Douglas-fir/snowberry habitat typemost frequently used during winter months and agrees with Tilton's (1977)
idings for sheep in the Thompson Falls herd. The pinegrass phase was mostiquently used within the PSME/SYAL habitat type.
,d Health
With respect to endooarasit( oads, Ural-Tweed bighorn sheep were relativelyhtly burdened. Protostongylid larval discharge from bighorn populations in.erton, Banff, and Jasper Farks, Canada, averaged 594, 626, and 2,375 per gram:es, respectively (Stelfox 1976). Uhazy et al. (1973) concluded that heavy.estation was reflected in larval counts over 1,400 per gram feces, whilemts averaging 157 larvae per gram feces were consioered light. The highest-val output for samples collected on the Ural-Tweed range was 262 larvae perLm feces, and annual average dischargo as 9.5 larvae per gram dry feces, in-:ating an extremely low lungworm infection intensity fc. these sheep. Forrt'sterI Senger (1964) reported a 100 percent infection rate, and a mean larval dis-trge of 970 larvae per gram feces for nine fecal samples collected from the Ural-ed herd in the early 1960's. This information suggests a much heavier lungworm R,den on these sheep previously, and probably reflects a higher sheep populationisity than at present. Stelfox (1976) found lungworm loads increased with sheep,ulation densities on Canadian sheep ranges, and this was especialy true durin,-,ere winters. Demarchi and Demarchi (1967), reported massive die-offs of Eas.)tenai sheep herds during the mid-1960's and attributed the decline to theigworm-pneumonia complex. Judging from the widespread nature of the die-offI realizing the nearness of these sheep herds to the Ural-Tweed population, itreasonable to suspect that this herd too may have experienced a suda n andiid decline. Presently, the Canadian herds have increased to near pre-crash,els; however, all seasonal components of their ranges have remained intact,i the Canadian Fish and Wildlife Branch has been continually involved ir rangeorovements through controlled burning. In contrast, since the md-196J's, theil-Tweed herd has been subjected to range reduction via Libby Dam Project, andige degeneration through lack of fire. In conjunction, these factors have, noibt, precluded post-die-off increases in sheep numbers, if indeed, a populationLah occurred.
od Habit
With the exception of February, May, July and August, grasses and grasslikeLnts constituted greater than 50 percent of all forages consumed by sheep.
..... : : _ -. .'-. . . •... ..- .. . . . .
RD-RI56 fi51 URAL-TWEED BIGHORN SHEEP INVESTIGAlTION(U) MONTANA DEPT 2/2OF FISH AND GAME HELENA G W BROWN 1979
ID DICRC67-76-C-0e83IUNCLAS7SIFIED F/G 6/3 NLEl..".
11111i 2-031
4-5
1- 25 6 i 1*4 nt 16
NATIONAL BUREAU (% STANDARDS11CROCOPY RESOLUTION TEST CHART
Specifically, rough fescue was the most common single forage species consumedduring every month of the year with the exception of February and May when
Douglas-fir a:Au serviceberry, respectively, assume temporarily greater densitiesin the diet. Bluebunch wheatgrass was consumed in lesser amounts than expectedconsidering its prevalence on the sheep range and rough fescue occurred in thediet more often than expected from its availability. Similar findings were re-ported for mountain sheep in South-Central British Columbia (Wikeem and Pitt1978). These authors formulated a diet preference index based on availabilityof the various forage species and found rough fescue was preferred over blue-bunch wheatgrass, and in fact, sho ed a high preference value when compared toits availability on the range during the four month period, May-August. Forbsbecame increasingly important for Ural-Tweed sheep during spring and summer monthswhen availability of this forage class was greatest. Shrubs assume dominance inthe diet of sheep during mid-winter and again in late spring. Increased use ofbrowse, Douglas-fir, serviceberry, oceanspray, bitterbrush, and snowberry occurredduring February, at a time when snow depths were 12-15 inches and snow conditionswere crusted and frozen during the latter part of the month. These conditionsmade bunch grasses very difficult for sheep to obtain. Renewed use of browse, par-ticularly serviceberry, during May and June, corresponds with the bloomin periodfor those shrubs, a time when terminal leaders and blooms have a high nutrientcontent. Percentage of forbs in the diet during spring and summer is consistentwith the availability and nutrieit status of this forage class and concurs withfindings of Wikeem and Pitt (197d) 'o found a very high sheep selection forforbs during spring and summer months.
Population Dynamics
Historically, the Ural-Tweed sheep range was morL extensive than it istoday, and appears to have supported a high population level approaching 200bighorn sheep in the early 1960's (Quick iC5). The population level at thattime may have exceeded range carrying capacity and a pop!'l".tion crash concurrenswith nearby Canadian sheep herd declines (Demarchi and Demarchi 1967) is sus-pected to have occurred, but could not be verified. Present'y, the Ural-Tweedpopulation of bighorn sheep consists of no more than 25 animals, and appears tobe still declining.
Interpretation of primary age ratios (lamb:ewe ratios) to determine popula-tion status and trend may be misleading if not considered in conjunction withother population parameters (Caurhley 1974). Dynamics of the Ural-Tweed sheeppopulation exemplify these pitfalls. The reproductive rate for Ural-Tweed sheepduring this project was as high or higher than that reported by either Ensign(1937) or Brink (1941) for this same population; however, both authors weredealing with a stable or increasinr population of approximately 100 animals,while the present population consists of fewer than 25 sheep and is declining.Lamb production was high, but so was lamb mortality during summer and winter.Consequently, juvenile recruitment into the population was low. Similar findinfswere reported for Jasper Park sheep by Stelfox (1976) and was thought to be anexpression of the Inversity Principle (Errington 1956), whereby the populationattempts to compensate low overall juvenile recruitment through hirh lamb pro-duction. Rates of natural attrition for older age classes, juvenile mortalityand emigration, plus unnatural losses are greater than the rate of juvenile in-corporation into the herd with consequent inadequate recruitment to maintain thecurrent population level.
_no..
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7,
Recommuendations
The Urai-Tweed sheep range was identified as a priority big game managementunit in the U.S. Forest Service Final Environmental Statement for the Inch Moun-tain Planning Unit. Management guidance recommends maintenance or enhancementof winter range to favor bighorn sheep. The present investigation has identifiedkey areas of seasonal importance to Ural-Tweed sheep and has quantified parametersof sheep habitat requirements which should be beneficial in project level planningdesigned to improve residual sheep range. The following general recommendationsare forwarded in the hope that they may be applied to the management of the Ural-Tweed sheep herd and its habitat.
1. Identified key use areas should receive first priority for habitatimprovement projects, while potential or marginal sheep habitat should receivesecondary consideration.
2. Large-scale or long-term projects should be timed to correspond withseasons of non-use or light use by bighorn sheep on specific key sites. Forexample, helicopter logging operations should not be conducted on the Allen Gulchlamnbing and nursery area during the period 15 April -30 June.
3. Habitat improvement on key use areas should be coordinated and designedin concert with specific sheep haL'i~at requirements for the season during whichthe site receives greatest sheep use.
4. Close coordination between the U.S. Forest Service and the MontanaDepartment of Fish and Game should be maintained in the ronceptual layout ofhabitat manipulation projects as field review of specific project sites.
5. Management guidance for areas b-low Highway 37 as outlined in the LandUse Plan, should be reevaluated considering the impor~anc of this area to biggame ungulates, especially bighorn sheep. The potential for improvement of springrange exists in this area and should not be overlooked.
6. Vegetative manipulation should favor increased production and improvedquality of bunch grasses, specifically rough fescue, Idaho fescue, and bluebunch
* wheatgrass. The importance of browse during mid-winter and late spring and offorbs during spring and summser should be recognized and treated accordingly.
7. Considering the historic importance of natural fire on the Ural-Tweedsheep range, a long-range fire management plan should be developed and used onthe area to retard conifer invasion and generally rejuvenate degenerating rangeconditions.
8. Sections of Highway 37 identified as problem areas for sheep crossingshould be considered for alterations to facilitate sheep access to lower slopeforaging areas and ups lope security areas.
9. The future of native sheep on the Ural-Tweed range is in doubt. The* * current population may have declined to a level below which further decline may
preclude response to habitat Improvement. The U.S. Forest Service and the De-partment of Fish and Game are formulating a contingency transplant agreement inthe event that indigeneous bighorns disappear from the range.* The remnant bandof sheep on the range should be closely monitored to determine if and when a
* supplemental introduction would be recommended.
-91-
LYPEATURE CITED
Aldous, M.C., F.C. Crairhead, Jr., and Gl.A. Devan. I <if. Some weigt andmeasurements of desert nih r sheep,. (Clvi:- (:anadcenvis, nel s onl. J. WI Al].Manage. 22(4) :444-42;5.
Anonymous. 1974. Fina.l environme iai L' te nt, mul I e use ;a,, 7 nMountain Planning Uin-'. U.S.F.- i. cCr , Koy:tenadI National Fore:-, EcoiBanger Dist., Mt. 46 pp .
Berg-eson, W.B. 2042. Lifncoln County gum -sudy, ia1OD'_r42 K--tena' lint.Mo-ntana Fish and Gam:e Dc-,artment. P-R 2-E:: r-. 7:
* Blair, B.M. 95.Imj a-' ro fhe rcLtrd Libby Dam u;n thr- w~~tr:v~-f Lincln County, Montana. Montana Fi'sh arid Game Y[%J X lCi
Restoration Division. P-B Inves' -ga"i: Pro,'. W-36-E, Work -:a.- X. v
Blo. ol, D.A. 16.Snase-cAehv ia rI - he-ru. ao.F i
* L~rit, lW. '41. Surr.ary re: 4n i v- ~ s~e r;e ttr7
Brow,,P G. W. 1974. DisEtributio Cn and ~:ulati 'n chara *eris*ti_-s of b~rh rn sh-ee:r1 ear Thompsozn Fall is: northwestern N:: mra. E,.S. es.U c' . -'<
Bv.;e h e r, H.K. :6(.0. The blghorni~ sheo~i I', Ire Uni-* e, t atro&and future. W-'lt-. yw; N> 4. 1.k
CughcyG. 12 ,. Irterrietatori -f aret raWu I. W l. V'~a-e ()
C ENM Ic 15C R' t Mour' air] ti rh :'unfe: cf Mo-nt an a. N: cw _.: F-'o.,(3are c C omras sir. c > n. 0
Daujrernn're, B. ant .Dubnle.Ir ForE::i veretat I-:r:U a~2i .u:1-and northern Tdan2-. WA AL-ri. Exr * &a,, Puflman Ten,. r w2 . c.
Dearden, B.L., B.E. Pci-a'., and R.M. Han-.sen. 2975 Pr'e:'f.f mi~r~l~Iest~mates o',f run 4 ian, f, 'd habits-. J. Wild!. Maa-e. ~.~ 42
Derrrchi, B.A. and D.A. Demarc-hI. IC> Status- c I' th.- hesky Mnta: irWil. Rev. 4(4):20--1.
&'isirn, W.W. 1 r,7. W in er rare E, ;dy of Wa r: hrl D-crie, o 9' t" I. n-tailed study of the lVra-mueai ban)d of Mo~unt-in SheeT'. 'LT.S. F.S. ret. LI .p
-92-
7I
Erickjon, G. L. 19(,'. The e,,?.-ory,,' J c fj -~ky M' 'LAI t ail' firrnr s I re; e ~r S,,River area piuntana. with specia. referen:.-tv U owrin.er food 1,a1_)*. and rang'F,-mocvements. M.S. Theflis, MSU, Bozernan. 110 p,
-ig-on P.L. 95'. F-t, rz 'irritinfc h';-fLei vertEcbra-te foc~a E,, 'i124 :504-307.
Fc-rrester, D.J. and C.M. Senk-er. lQ.A survey of lun -worn. infeti~ -'n bi-J;-hbrr.sheep of Montana. J. Wildl. Na -c_2e. 41a4,
Geist, V. 1966. Validity of' horn segnberv counts in aging bigFhor., shec-. J.Wildi. Manage. 30(_):(34-635.
Gei rt V. 1971. Mo-untain- Sheer-: A study i;n behavior ann- ev- zcr. :vChicago press, Chioago_- and Londcn-,. 32 3~
Hebert, D.M. 1973. Altitudinal riratlcm as a fa!tl-r, in the urtcn :orcrnsheep. Ph.D. Thesis. Uni'v., B.C., Vancc- uver. i 4&
JTslin, G. 19, '7,. Kootcnai Fali s wildlife inventoryv. Fi nal e;-N:i DenJ.of Fish and Game. 49 pp.
*MatthewO, J.W. 1973. Ecology cf bighorr Eecr :n Vldr'osc Iclan. Fitrea Lake.Mot,' aria. M.S. Thesis, Univ. Mvh., Miss-u~a. ;
N, rirar, J.K. 1970 Ec-ologyv -f the Ncrgai. Creek anid E_ F -rk R:~a'~1L:7rn sheep herds and mnragement of bigh- rr sheer 9 o .P.saI '
ion repocrt , idash. Fi n and Game De-. art (,nt, EB i se. *r ~W- k'-P-.-
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I
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