Loading...
HomeMy WebLinkAboutAPA2785~--------------------------------------------------------------- I I I I I ALASKA DEPARTMENT OF FISH AND GAME -... JUNEAU, ALASKA S-TATE OF ALASKA Bill Sheffield, Governor DEPARTMENT OF FISH AND GAME Don W. Collinsworth, Commissioner DIVISION OF GAME W. Lewis Pamplin, Jr., Director Steven R. Peterson, Research Chief HOME RANGE DYNAMICS OF WOLF PACKS ON WINTER RANGE OF THE WESTERN ARCTIC CARIBOU HERD By David D. James Final Report Federal Aid in Wildlife Restoration Project W-22-2, Job 14.12R / Persons intending to cite this material should obtain prior permission from the author (s) and/or . the Alaska Department of =~~~ and Game. Because most reports deal with preliminary QL 737 .C22 l36 1982·83 lt s of continuing studies, conclusions are tentative and ld be identified as such. Due credit would be appreciated. (Printed May 1984) 1 I l l -.-.1-,___. ] ] -1 J. ~l J J J -J . J State: Alaska Cooperator: None Project No.: W-22-2 Job No.: 14.12R Project Title: Big Game Investigations Job Title: Home Range Dynamics of Wolf Packs on Winter Range of the Western Arctic Caribou Herd Period Covered: 1 July 1982 through 30 June 1983 SUMMARY This project was designed to determine the spatial organization and movements of wolf packs (Canis lupus} during late winter on the Western Arctic Caribou (Rangifer tarandus) Herd (WACH) winter range, and to evaluate the accuracy and reliability of the wolf aerial survey technique used by the Game Division mainly in Interior and Southcentral Alaska. Environmental conditions under which the survey technique is successfully applied often do not exist in Northwestern Alaska. Therefore, results of wolf surveys in Northwestern Alaska are probably subject to an unknown but greater degree of error. Results of this research project were intended to be used as follows: 1) to identify the cause and extent of errors in wolf population estimates resulting from the survey techniques, and 2) to modify the technique or at least incorporate the limitations of it into the data analysis. Beginning 2 March 1983, Game Division personnel attempted to radio-collar 3 wolves in each of up to 8 pac~s. Only 1 pack was located during 3 days of searching a 7,700 km area including the Selawik Hills, Buckland River, a·nd Tagagawik River in southern Game Management Unit (GMU) 23. One young adult male wolf was radio-collared, but attempts to radio-collar additional wolves in the same pack at a later date were canceled when it became ap- parent that no other packs could be located. Success of the pro- ject depended on radio-marking at least 5 packs~ the project was therefore terminated. In conclusion, the necessity to continue using the wolf aerial survey technique, despite its shortcomings, was acknowledged. The need for a research project to evaluate the applicability of the survey technique still exists, but a substantially higher wolf population must be present to successfully conduct the pro- ject. Key words: aerial survey, Canis lupus, caribou, ra~io collar, Rang1fer tarandus, wolf. i ARLIS Alaska Resources Library & Information Services Library Building, Suite 111 3211 Providence Drive Anchorage, AK 99508-4614 ]. ]· J J cl I ::J• J J J Lj CONTENTS Summary. . . . . . . . . . . . . . . • . . . • . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Objective ................................................... 2 Study Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Methods. • • • • • • . • • • • • • • . . • • • • • • • • • • . . • . . • • . . . • • • . . . • • . . . . . • • • 2 Results and Discussion................... . . . . . . . . . . . . . . . . . . . 3 Recommendations •••••••.••••••••••••••..••...••.•••...••.••• ~ 4 Acknowledgments..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Literature Cited ••.••••••••••••.•••••.•••..••••••.•..••.•.•• 4 BACKGROUND The wolf aerial survey technique (Stephenson 1978) is used rou- tinely in late winter by Game Division biologists to estimate the number of wolves (Canis lupus) in specific areas throughout much of Alaska. This method has been tested and proven to be highly accurate in Southcentral Alaska (Stephenson 1978, w. Ballard, unpubl. data) where wolf pack territories are stable 2 where wolf densities do not exceed approximately 1 wolf/65-90 km , and where wolf surveys are completed within relatively short periods of time. However, the applicability of this technique may be limit- ed in northern Alaska on winter range of the Western Arctic Cari- bou Herd (WACH) for the following reasons: 1) Many wolf packs are migratory (Kelly 1954, Stephenson 1979, Stephenson and James 1982, James 1983) and may not maintain territories during winter; 2) Wolf densities on caribo~ (Rangifer tarandus) winter range may be as high as 1 wolf/16 km in the vicinity of winter aggrega- tions of caribou (Kelly 1954, Kuyt 1972, Miller 1975, J. Davis, pers. observ.); and 3) Wolf surveys on the WACH range often re- quire relatively long periods o£ time to complete because of fre- quent poor weather and difficult logistics. The accuracy of existing wolf aerial survey techniques on winter range of the WACH is unknown primarily because the degree of sta- bility of wolf pack territories during late winter when surveys are conducted is unknown. If territories are not stable during this period, then movement of packs may cause some animals to be missed or counted twice. If pack territories are unstable, addi- tional errors in density estimates may result when surveys are extended over several days, thereby allowing more time for move- ment of packs. If unstable pack territories or other factors decrease the relia- bility of the wolf aerial survey technique, then the cause and extent of errors in wolf population estimates using the technique should be identified. Some modification of the technique may be possible; minimally, realizing the technique's limitations will make it more useful in Northwestern Alaska. 1 OBJECTIVE To determine the spatial organization and movements of wolf packs during late winter on the WACH winter range, and to evaluate the accuracy and reliability of the wolf aerial survey technique. STUDY AREA The area chosen for this investigation was the Selawik Hills/ Buckland River/Tagagawik River portion of GMU 23. The study area is bounded on the north and south by 66° 30' N and 65° 15' N latitude, respectively, and on the west and east by 161° 30' W and 158° 30' W longitude, respectively. According to Wahrhaf- tig's (1965) physiographic nomenclature, this area falls within the Western Alaska Province and consists primarily of the Selawik Hills and Buckland River Lowland sections. The Selawik Hills are generally rounded, rising steeply to the north and declining gently to the south, with summits to 1,015 m. The Buckland River Lowland varies from sea level to 308 m and is a gently rolling, open lowland dissected by several tributaries. Tundra is the predominant vegetation, with shrubland localized on protected upland slopes and river valleys. Spruce (Picea spp.) forest is even more localized on some riparian sites and on some upland slopes on the southern edge of the study area. The Selawik Hills/Buckland River area is one of the 3 most impor- tant winter ranges of the WACH. The herd has used this area con- sistently for at least the last 30 years, even during the mid- 1970's when the herd had declined to approximately 75,000 animals (Davis and Valkenburg 1978). This area is also a well-known favorite location for aerial and snowmachine-borne wolf trappers and wolf hunters (D. James, pers. observ.), because relatively large numbers of wolves are frequently present in winter along with the caribou. METHODS Attempts to initiate the study failed; the following is a description of how the study was to have been accomplished. Three wolves in each of up to 8 packs were to have been radio- collared in February or March 1983. Fixed-wing aircraft were used to locate wolves, and a standard helicopter darting tech- nique using M99 was the means of capture. Instrumented wolves were to have been located twice weekly for the remainder of the late winter and spring. These locations would have been used to define a minimum area home range (Mohr 1947) for each pack and to determine whether each pack occupies an exclusive home range (territory) or whether different packs share a common home range. The study wolves were to have been located at 4-to 8-week inter- vals during summer and fall to determine seasonal movement pat- terns. 2 c~ I -:-:1---- -,. ]· ~ '~] ] -, I ,_j, J· J Wolf density in the study area was to have been estimated inde- pendently in the following 2 ways: 1) by using radio-collared individuals to help locate packs, and 2) by using the convention- al wolf aerial survey technique. The results of method #1 would have been considered more accurate than those of method #2. Any discrepancy in density estimates would have been analyzed in light of the detailed movement and distribution data obtained by radio tracking. This analysis would have been the basis for a modified survey technique suitable for conditions encountered on caribou winter range in Northwestern Alaska. RESULTS AND DISCUSSION On 2-4 March 1983, Game Division personnel attempted to locate and radio-collar wolves in the study area which contained 40,000- 60~000 wintering caribou. During 3 days of searching the 7,700 km area, a pilot-observer team in a Super Cub was able to locate only 1 pack of wolves and 26 additional sets of tracks. Nor were any wolves seen by an on-the-ground observer using a spotting scope on high vantage points, a technique used successfully in the Western and Central B-rooks Range in the past. Very poor snow conditions in the Selawik Hills area (where most of the caribou were located) and marginal conditions to the east limited our ability to make aerial and, to a lesser degree, on-the-ground observations. Wolves and wolf signs probably would have been observed more often under ideal tracking conditions. Even so, fewer wolves were observed than would be expected for an area in which one-third of the WACH was wintering. One radio collar was attached to a young adult male wolf in the only pack observed. Attempts to radio-collar additional wolves in this pack a-t-a later date -were canceled when it became appar- ent that no other packs could be located. This decision was made as a result of previous agreement by agency principals that if the primary objective of the study (which required a relatively large number of radio-marked packs) could not be met, then the study should be terminated. The single radio-collared wolf was shot less than 1 month after collaring, approximately 6 mi from where it was captured on the lower Tagagawik River. The radio collar was returned to the Kotzebue Fish and Game office. Pending the outcome of a successful research project, the appli- cability of the wolf aerial survey technique in Northwestern Alaska will remain conjectural. In the meantime, the survey technique remains the only way to estimate wolf abundance even if results are ambiguous relative to those obtained elsewhere in Alaska. Observations from this study and associated management activities suggest that the wolf population is productive but has been stabilized at a low-to-moderate level by hunting, trapping, and perhaps other mortality. Inability to locate more than 1 wolf 3 pack during the radio-collaring attempt suggests that wolves were relatively scarce. When wolves were last known to be abundant in the study area (mid-1970's), wolf signs, including caribou car- casses, tracks, and chance sightings of wolves, were frequently observed on caribou winter range (P. Valkenburg, pers. commun.). During the 1983 radio-collaring attempt, caribou carcasses other than those apparently killed by hunters were rarely observed, wolf tracks were relatively scarce, and no chance sighting of wolves were made. Local hunters and trappers, however, believe that wolves have increased during the past 2 years. This belief is consistent with the fact that 12 wolves were reported har- vested in the study area during winter 1982-83, and at least 30 more were believed to have been taken by local hunters and trap- pers, but not reported. If the harvest was actually that large, wolf densities must have been moderate-to-high prior to winter hunting and trapping removal. RECOMMENDATIONS This research project, or one similar to it, should be initiated when it becomes apparent that wolf packs are sufficiently numer- ous to ensure successful radio collaring. The conventional wolf aerial survey technique should continue to be used in Northwestern Alaska, with the realization that results will be more difficult to interpret and possibly less accurate than those obtained from Interior and Southcentral Alaska. ACKNOWLEDGMENTS D. Craighead, T. Smith, and R. Quimby of the Alaska Department of Fish and Game gave this project their "best shot" and I appre- ciate it. Pilots J. Rood of Northwestern Aviation and E. Pent- tila of Evergreen Helicopters provided, as always, safe and pro- fessional flying. LITERATURE CITED Davis, J. L., and P. Valkenburg. Herd studies. Alaska Dep. Wildl. Rest. Final Rep. 3.19R. Juneau. 26pp. 1978. Western Arctic Caribou Fish and Game. Fed. Aid in Proj. W-17-8 and W-17-9, Job James, D. D. 1983. Seasonal movements, summer food habits, and summer predation rates of wolves ~n northwestern Alaska. M.S. Thesis. Univ. Alaska 7 Fairbanks. 105pp. Kelly, M. W. 1954. Observations afield on Alaska wolves. Page 35 in Proc. Alaska Sci. Conf. 5:35. u.s. Fish and Wildl. Serv., Juneau. (Abstr.). 4 J J J l I ~ _j' ~1 ' ··~J l j 1 _j .. , i ~ l Kuyt, E. 1972. Food habits and ecology of wolves on barren ground caribou range in the Northwest Territories. Can. Wildl. Serv. Rep. No. 21. Ottawa. 116pp. Miller, D. A. 1975. Observations of wolf predation on barren ground caribou in winter. Pages 209-220 in J. R. Luick et al., eds. Proc. 1st Intl. Reindeer/Caribou Symp. Biol. Pap. Univ. Alaska, Spec. Rep. No. 1. Fairbanks. 551pp. Mohr, C. 0. 1947. Table of equivalent populations of North American small mammals. Am. Midl. Nat. 37:223-249. Stephenson, R. 0. 1978. Characteristics of exploited wolf populations. Alaska Dep. Fish and Game. Fed. Aid in Wildl. Rest. Final Rep. Proj. W-17-8, Job 14.3R. Juneau. 21pp. 1979. Abundance, movements, and food habits of wolves in and adjacent to NPR-A. Pages 53-87 in P. C. Lent, ed. Studies of Wildlife and Fish and their--Use of Habitats on and adjacent to NPR-A, 1977-78. Vol. I. U.S. Dep. Inter. Anchorage. 226pp. , and D. D. James. 1982. Wolf movements and ---f-:='o-o-:::d,.........,h,....a.....,br-:-i-:-t-s in northwest Alaska. Pages 26-42 in F. H. Harrington and P. C. Paquet, eds. Wolves of the World. Noyes Publ. New Jersey. 474pp. Wahrhaftig, C. 1965. Physiographic divisions of Alaska. Geol. Surv. Prof. Pap. 482. Washington D.C. 52pp. PREPARED BY: David D. James Game Biologist II SUBMITTED BY: David A. Anderson Acting Research Coordinator APPROVED BY: Research Ch~, Division of Game ;r .,, ::i' . '· J . ·'"· b. ·' 5