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1 Selawik NWR Progress Report 85-1 MOOSE AND CARBOU POPULATON ESTMATES, TREND AND DSTRBUTON SURVEYS ON SELAWK NATONAL WLDLFE REFUGE 1984 ' Michael A. Spindler Kent F. Hall Key Words: Moose, Alces alces, Caribou, Rgngi!~ tarandus, Kotzebue Basin, Selawik River, Tagagawik River, Kugarak River, aerial surveys, population estimation Selawik National Wildlife Refuge u.s. Fish and Wildlife Service P.O. Box 270 Kotzebue, Alaska April 1985 ARLS Alaska Resources Library & nformation Services Al Al ka

2 Selawik National Wildlife Refuge Progress Report 85-1 Moose and caribou population estimates, trend, and distribution surveys on Selawik National Wildlife Refuge, Alaska, 1984 The Selawik National Wildlife Refuge (Selawik NWR) was established in part to provide wintering habitat for the Western Arctic Caribou Herd (WAH). Moose, recently expanding their range into northwest Alaska rapidly expanded in numbers, especially in portions of the refuge that burned during widespread brush and tundra fires in Additionally, both moose and caribou are hunted for subsistence and sport purposes on Selawik NWR. Refuge studies addressing numbers and distribution of moose and caribou had 3 specific objectives: (1) determine seasonal and annual population trends in moose; (2).estimate population levels of moose and caribou; and (3) document distribution of migrating and wintering caribou. Moose Methods and Materials Trend surveys. For trend surveys a 91 mi2 study area was established W of the Tagagawik River on the southern portion of the refuge. The area had been cursorily surveyed by Roland Quimby, Alaska Dept. of Fish and Game (ADF&G) Kotzebue area biologist, in March 1984, and identified as a major winter concentration area inhabited by high densities (for this region) of moose following a 1977 brush fire. Additionally Mr. Nelson Walker, Kotzebue pilot and guide, indicated that the first moose to colonize the region were seen by him in the Tagagawik River drainage around Because of the high densities reported and known fire and colonization history, the area was selected for trend monitoring purposes. n the Tagagawik study area moose densities were estimated to be 2-5 times higher than those of surrounding areas, allowing a large number of moose to be surveyed in a short amount of flying time. No attempt was made to determine sex of moose in spring surveys. n the fall surveys considerable circling over moose groups was required to be sure yearling bulls would not be mistaken for cows. Trend surveys were flown with a Piper Super Cub. Census. For the moose census a stratified random sample of mi2 sample units was selected according to the ADF&G moose census manual (Gasaway et al. 1980). This pre-stratified according to known or estimated moose Aerial surveys of the trend area and sample standardized with 1/4 mile-wide transects flown with a sample was densities. units were Piper Super

3 - Cub at an altitude of 500 ft. AGL. A consistent coverage intensity of 2 minutes/mi2 was maintained whenever possible. (The intensity of half the 4 minutes/mi2 recommended for interior Alaska seemed most reasonable based on the more open tundra-like terrain of Selawik NWR.) Survey intensity of up to 4 minutes/mi2 was used on the 2 sample units which were forested. Sightability correction factors were not applied to population estimates because of the predominantly open terrain. Diversions from the transects and 500 ft altitude were made to confirm composition identifications and/or search thicker vegetation clumps more intensively. Caribou Census. Population estimates fo~ caribou were initially obtained from aerial transect extrapolations (September 1984), but confidence limits were exceedingly high dictating an improved procedure. Therefore, in December 1984 caribou were counted on all moose census sample units as described above, however, the sample was pre-stratified based on known caribou distribution. Distribution. Distribution surveys were flown January through May and september through December using Cessna 185, 206, 207, and Piper super Cub aircraft. Radio telemetry collars placed on WAH caribou by ADF&G were received using a Telonics TR-2 Receive~ and Scanner. Emphasis of distribution surveys was to monitor migration and document routes and wintering areas, hence general locations instead of exact and/or visual locations were desired. All locations were recorded on 1:500,000 scale sectional aeronautical charts and on ADF&F caribou telemetry forms. All telemetry forms were filed at the USFWS office in Kotzebue and copies were sent to ADF&G in Nome. Moose Results and Discussion Trend surveys. The spring survey yielded a total of 146 moose, including 18 cows with 21 calves, and an overall density of 1.6 moose/mi2 and 38 moose/hr, (Table 1). More moose were seen in the same area in less survey time in the fall-- a total of 176 moose, 29 cows with 33 calves, and an overall density of 1.9 moose/mi2 (Table 1). We can be sure that there was a slight increase in cows with calves as well as moose density and numbers of adult moose (125 in spring and 143 in fall).. As would be expected, more calves were seen in the fall survey than the spring survey, probably due to winter mortality, but calves per/100 adults was also slightly higher in the fall survey. t will be another year before meaningful annual population dynamics and trend comparisons can be made using the detailed statistics gathered from the fall 1984 survey. Census. A total of 15 sample units representing 318 mi2, or 9% of the 3359 mi2 Selawik NWR (unselected lands) was censused 4-19 December (Fig. 1). Totals of 1799 moose, including 1001 cows, 302 calves, and 496 bulls were estimated on unselected

4 ., Table 1. Summary of spring and fall moose population statistics for the Tagagawik River study area, a 91 mi2 portion of the 1977 burn, Selawik National Wildlife Refuge, Alaska, Statistic Spring 1984 Fall 1984 Large Bulls n/a 5 Medium Bulls n/a 19 Yearling Bulls n/a 12 Total Bulls n/a 36 Cows w/o calf n/a 78 Cows w 1 calf Cows w/2 calf 3 4 Total Cows Total Calves Unident. Adult Total Adults Total Moose Total Bulls/ 100 cows n/a 33.6 Small Bulls/100 cows n/a 11.2 Calves/100 adults Calves/100 cows n/a 30.8 Small Bulls % in herd n/a 6.8 Calves % in herd Moose/hour Total survey time (hr) Moose per mi Dates of survey 10 April 4,5 December

5 N 1 MOOSE SAMPLE UNTS AND DENSTY ESTMATES SELAWK NATONAL wildlferefuge...,.,,_o & Sti""J< fltt., A ~ -{:,1/'od N Fig. 1. Distribution of randomly-selected sample units (indexed by top numeral) accompanied by resulting moose density estimate (bottom numeral), Selawik National Wildlife Refuge, Alaska, 4-19 December 1984.

6 , portions of the refuge (Table 2). The.most precise estimates were achieved for total moose and moose cows, where the 90% confidence limits did not exceed 25% of the estimate. Gasaway et al. (1980) recommended striving for ideal confidence limits of 20% of the estimate. Estimates for bulls and calves were not so precise, with confidence limits 50% and 55% of the estimate, respectively. The higher variance in these population segments suggested greater spatial variability in distribution of bulls and calves. The greatest densities of moose ocurred in the Tagagawik study area, a 1977 burn (Fig.l). Raw data indicated that a greater proportion of bulls occurred within sample units in the Tagagawik area and also 1 sample.unit in the Kerchurak Creek area (Appendix 1). The highest densities of calves were encountered only in the Tagagawik study area. Future moose censuses should focus on reducing the size of the confidence interval through increased sample sizes and optimal allocation of sampling effort, a procedure identified in Gasaway et al but which requires prior knowledge of variances. Overall moose density on Selawik NWR was estimated to be 0.52 moose/mi2. By comparison, densities in the best moose habitat in the south side of the Brooks Range in the Arctic National Wildlife Refuge ranged from 0.21 moose/mi2 (Sheenjek River 1977) to 0.28 moose/mi2 (Sheenjek River 1979) (Spindler 1980). Densities north of the Brooks Range have been observed to be locally higher, 0.38 moose/mi2 in the Canning River (Martin and Garner 1984), and even higher in the Colville ~iver area (E. Mould, pers comm). Yet higher densites have been observed in interior Alaska, moose/mi2 recently, and up to 3.9 moose/mi2, historically, in the Tanana River flats near Fairbanks (Gasaway et. al. 1983). Moose density on Selawik NWR in 1984 therefore exceeded recently observed densities farther north, equalled recent densities near Fairbanks indicative of a low or recovering moose population, and were exceeded by historical peak densities in the same Fairbanks population. t should be noted that densities in the Tagagawik study area on Selawik NWR were 2.02 moose/mi2, (Appendix 1) an intermediate value relative to low and peak values for interior Alaska. Caribou Census. Moose census sample units separately pre-stratified for estimated caribou abundance indicated 8496 caribou plus/minus 5233 on Selawik NWR, 4-19 December The larger 90% confidence interval was 61% of the population estimate, indicating that more sample units should have been sampled, especially in the high stratum. A 12 September population estimate extrapolated from 8 linear aerial transects totalling 124 mi2 in area yielded 5174 caribou plus/minus A definite improvement in size of confidence limits was achieved by changing to an aerial plot method, and sampiing a greater percentage of range. Cameron et al. (1984) indicated that reliable (within 20%) confidence limits were not achieved in summer in the Prudhoe Bay area until 33-50% of the area was covered by aerial transects. Siniff and Skoog (1984) achieved confidence limits 22% of their estimate by

7 Table 2. Moose, caribou, and Miscellaneous population estimates based on a stratified random sample of 15 sample units (totalling mi2 or roughly a 9% sample by area) in Selawik National Wildlife Refuge, 4-19 December Species/Class Population estimate 90% Confidence limit (C. L.) C.L. percentage of estimate Confidence interval Total moose Moose bulls Moose cows Moose Calves Caribou , 72r Red Fox 232a lob Wolverine 232a lob a Estimate based on simple random sample. b Estimate based on weighted stratified sample.

sampling caribou in 32% of all possible sampling units which represented 3.8% of the total area of the Nelchina Basin used by caribou in 1962.

8 sampling caribou in 32% of all possible sampling units which represented 3.8% of the total area of the Nelchina Basin used by caribou in From these data it appeared that at least 33% of all sample units or transect area had to be sampled to achieve confidence limits within 20% of estimated wintering caribou numbers, a 3-4-fold increase over our sampling intensity. Unless a large portion of the total western arctic caribou herd winters on Selawik NWR, it is doubtful such sampling intensity would be justified. Patterns of caribou density indicated a maximum on the Selawik River flats between the Waring Mountains and Selawik River, relatively high densities along the Kugarak River, and moderate densities on the upper Selawik River (Fig.~). Relatively high densities also occurred E of nland Lake and E of the Tagagawik. River N of the continental divide. / Distribution--Winter WAH Caribou began crossing the Kobuk River enroute to wintering areas in late August 1983 and peaked about 5-10 september. A flight on 8 September tallied nearly 9,000 caribou in scattered small bands on the refuge N of the Selawik River. The flight amounted to a single transect S of Ambler along the Kugarak River E of Rabbit Mountain to the selawik River. Caribou were observed S of the Selawik River. Lack of funds precluded further flights until 6 October. By that date most caribou had moved S of refuge lands. Personnel of ADF&G "installed" 10 radio telemetry transmitters on swimming caribou in the Kobuk River near Ambler the week of 10 September Only one of the tra_nsmitte.red caribou was heard on a relocation flight over the refuge on... 6 October. Weather and lack of daylight precluded adequate monitoring until February,; ADF&G confirmed that large numbers of caribou were presentv- on the eastern Seward Peninsula and Talik Ridge area S of the refuge. All 10 of the 1983 transmittered caribou from Ambler were accounted for in early February. Another 12 transmitter frequencies were also heard during relocation flights made October 1983 through May, All were south of refuge lands, with 3 in the drainage of the Shaktoolik River. Major concentration areas~ were the Selawik Hills, West Fork of Buckland River, and Talik Ridge easterly to Tagagawik River. Extensive relocation flights were begun in mid-march 1984 to document caribou migration routes and use on the refuge. The flights revealed that major staging areas existed in the Talik Ridge area S of the refuge and in the eastern Selawik Hills and adjacent Tagagawik River area involving both refuge and non-refuge lands (Fig. 3). Telemetry flights confirmed a movement to and build-up of numbers in this area during March and April. According to ADF&G personnel and local people, most caribou are usually N of the Kobuk River by mid-to late April. n spring 1984, the major movement of northward migrating caribou crossing the Kobuk River occurred from May as evidenced by trails and telemetry relocations. The late date was probably influenced by unseasonably cold and stormy weather through April. An effort was made to estimate numbers of caribou during a 5 April telemetry flight. Subjective estimates were made using

9 N CARBOU SAMPLE UNTS AND.DENSTY ESTMATES SELAWK NATONAL WL DL l FE REFUGE 1.,S(.t..AWJ( Ji?.VC:.~ Ft..,rS 03'1- /8-98 Fig. 2. Distribution of randomly-selected sample units (indexed by top numeral) accompanied by resulting caribou density estimate (bottom numeral), Selawik National Wildlife Refuge, Alaska, 4-19 December 1984.

10 binoculars at approximately 10,000' AGL. This prbcedure provided the necessary perspective, given the limited! amount of time available in a single f~ight, to assess concentra~ions, and still preclude double counting of migrating animals. The numbers tallied were 20,250 in the Selawik Hills and 7,050 in the Talik Ridge area.,'based on telemetry signals received and not received, there were caribou in places not visited. Totallnumbers in other areas were unknown, but the areas censused presented major use ~ areas based on observation of trails and cratering (Fig. 3).~ ~ ' Distribution Winter The first caribou crossing the Kobuk River were observed heading south 31 August, About 1,000 animals were observed in small bands S of A~ler, and N of the Rabbit River. ADF&G biologists installed 2 transmitters on swimming caribou near Ambler during early S~ptember. They intended to fit 8 other caribou with transmitters, however caribou unexpectedly ceased crossing, and additional tran~mitters were not installed. On 12 September an aerial transect flight revealed approximately 5700 caribou widely distributed acrdss refuge lands with no specific concentration areas. n odtober, there was evidence of a large movement S across the Purcell Mountains. A telemetry relocation flight made on 1 Novembe~, indicated that only 2 active signals were attributable to refuge 1ands. One of 1 the 2 collars installed September 1984 was relocated near the mouth of the Kugarak River with about 25 caribdu. The second frequency was located in a group of 10 caribou [approximately 15 miles S of Purcell Mountain (Fig. 4). This animal also carried a satellite transmitter which had been fitted in ~he spring during northward migration across the refuge. On 1 NO:vember, Caribou were observed concentrated in the area S of the ~aring Mountains~ as far w as 10 miles N of Selawik Village and eiasterly to the Kugarak River (Fig. 4}. peveral bands were observ,.ed along Selawik River near ;,nqruksukililsj Creek. About 100 caribbu were observed near the FWS cabin on 7 November. i Caribou distribution in December 1984 was simi~lar to earlier in the fall with an estimated 8496 remaining in the area s Waring Mountains between Selawik Village and the Kugarak River (Fig. 4). These wintering caribou apparently remained in the same or adjacent area until late March ~~~Y-- ~pril they had begun moving N into the Waring Mountains. ~ large (about 5-10,000) group of caribou in the Selawik Hills had not begun moving N onto the refuge by early April. Literature Cited i Cameron R.D., K. Whitten, W.T. Smith, and D.J. Reed Sampling errors associated with line-transect $urveys of caribou. in Proc. 2nd N. Am. Caribou Workshop, McGill Univ. Montreal. Gasaway, w.c., Manual: a s. Dubois, and S.J~~Harbo preliminary draft. El~ska Dept. ~ ' -... '" Moose census ofifish and Game,

11 --61'<»' tt.z oo w N 1 SC'AL SELAWK NATONAL WLDLFE REFUGE ~....S c. w >< RYt:'t 1\ F<.A.r!i ~ -Ml'OO' N Fig. 3. Caribou distribution on Selawik National Wildlife Refuge, Alaska, Spring 1984.

12 N SELAWK NATONAL WLDLFEREFUGE 1 S C 4 L ( N4.f( Ji;AtJ~ UtLLS " l(o8~jl( \/U.L ~ Fig. 4. Caribou distribution on Selawik National Wildlife Refuge, Alaska, Fall-Winter 1984.

13 Fairbanks Alaska. Xerox draft. SOpp. Gasaway, W.c., R.O. Stephenson, J.L. Davis, P.E.K. Shepherd; and o. Burris nterrelationships of wolves, prey, and man in nterior Alaska. Wildl. Monogr. 84:1-50. Martin, L.D. and G.W. Garner Population size, composition, and distribution of moose along the Canning and Kongakut Rivers, in the Arctic National Wildlife Refuge Alaska, fall Pp in G.W. Garner and PE. Reynolds (eds.) 1983 Update Report Baseline Study of the fish, wildlife, and their habitats, Arctic National Wildlife Refuge Coastal Plain resource assessment. u.s. Fish and Wildlife Service, Anchorage, Ak. 614pp. Siniff, D.B., and R.O. Skoog Aerial Censusing of caribou using stratified random sampling. J. Wildl. Manage. 28: Spindler, M.A Fair 1979 Moose surveys--sheenjek, Old Woman, and Coleen drainages and Spring 1980 Moose surveys- Canning and Konqakut Rivers. Memos to the refuge manager Arctic National Wildlife Refuge, u.s. Fish and Wildlife Service, Fairbands, Ak (Xerox) 18pp.

14 High Total 94.2 density (moose/mi2) Low Total density (moose/mi2) Total area per stratum Total units sampled per stratum Total possible units per stratum 507 mi mi

15 Appendix 2. Caribou census data for Selawik National Wildlife Refuge December 1984 Sample Unit Area Quad & no. (mi 2 ) High Stratum Low Shg DS Sel D Shg C Shg B Shg B Shg B Sel B Sel A Sel A Sel A Sel A Sel B Sel D Shg BS Shg A High Total density (caribou/mi2) Low Total density (caribou/mi2) Total area per stratum Total units sampled per stratum Total possible units per stratum m mi

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