Carfentanil

ABSTRACT. Moose (Alces alces andersoni) occur at low density (140-160 moose/1000 km'Symbol not transcribed'2) and are the most important game animal in much of the Mackenzie Valley, western Northwest Territories. Productivity and survival of 30 female moose ( 1.5 yr.) were studied from November 1985 through November 1988. Twenty-nine of these moose were radio-tracked for a total of 1039 relocations. Pregnancy rates were 96% for adult and 40% for yearling females. Most females returned to the same restricted area to calve each year. Mean newborn calf:female ratio and twinning rates were 1.2:1 and 31%, respectively. Mean annual female survival rate was 85%. Annual calf survival was high and stable (44 0.02%). Individual total home range size varied from 40 km'Symbol not transcribed'2 to 942 km'Symbol not transcribed'2. Mean home range size for 29 moose was 174 31 km'Symbol not transcribed'2 and 202 59 km'Symbol not transcribed'2 for the 14 moose radio-tracked the entire three years of study. Fall home ranges were twice the size of winter and summer home ranges; seasonal ranges overlapped widely, indicating that these moose were non-migratory.

Key words: moose, low density, productivity, movements, Mackenzie Valley, Northwest Territories

INTRODUCTION

Moose have long been the most important ungulate to both aboriginal and sport hunters along the upper and mid-Mackenzie Valley in the western Northwest Territories (N.W.T.). Annual moose harvest has remained light at 4% to 5% of the total population largely because of the sparse human population and lack of road access. Aerial surveys using the stratified block design (Gasaway et al., 1982) indicated a low density of 155 moose/1000 km'Symbol not transcribed'2 on the study area (Government of the N.W.T., Department of Renewable Resources, Norman Wells, N.W.T., unpubl. data). This density is similar to portions of the northern boreal forest of the Yukon and central Alaska where moose are the major prey of lightly harvested wolf (Canis lupus) and grizzly bear (Ursus arctos) populations (Gasaway et al., 1992).

Hydrocarbon exploration and extraction have a long history in the mid-Mackenzie Valley. In the early 1980s, the oil field at Norman Wells underwent expansion, and exploration accelerated in outlying areas, raising concerns about possible effects on seasonal movements of the moose in the Mackenzie Valley, especially during winter. Concerns also arose about increased hunting pressure stemming from a larger human population.

The present study of productivity and movements of female moose was initiated to obtain information necessary for managing this low-density moose population. Our study objectives were to determine the productivity, survival, home range size and seasonal movements of female moose. No such published data existed for moose in the extreme northern portion of the boreal forest typical of northwestern N.W.T. and central Yukon and Alaska.

STUDY AREA AND METHODS

The 2838 km'Symbol not transcribed'2 study area is situated in the Mackenzie Valley between the Mackenzie River and the front range of the Mackenzie Mountains (Fig. 1). The area lies within the northern boreal forest and has low relief with an average elevation of 250 m above sea level. The climate is subarctic with mean daily minimum temperature for the year of-11.2DegreeC and a mean maximum of -1.5DegreeC. Mean daily temperature in January is -28.9DegreeC and in July is +16.3DegreeC. Mean annual snowfall is 146.8 cm and rainfall is 183.3 mm (Environment Canada, Norman Wells, N.W.T., pers. comm. 1992).

Much of the area is poorly drained and consists of both open and partially closed black spruce (Picea mariana)-moss-lichen and black spruce-bog forests (Hare and Ritchie, 1972) interspersed with small lakes and streams. Better-drained upland areas and stream bottoms contain stands of white spruce (Picea glauca), balsam poplar (Populus balsamifera), white birch (Betula papyrifera), aspen (Populus tremuloides), willow (Salix spp.) and alder (Alnus spp.). Ice and flood action keep much of the vegetation along major river drainages in early successional stages. Periodic forest fires have also created areas of differing regenerative stages. Numerous abandoned exploration roads and lines cut for seismic exploration cross the study area. Potential predators of moose such as wolves, grizzly bears and black bears (Ursus americanus) exist at unknown densities.

Female moose ( 1.5 yr.) were located from a Bell 206B helicopter in November 1985 and 1986 and immobilized with 3 mg of carfentanil (Wildnil'Symbol not transcribed'(C), Janssen Pharmaceutical, Mississauga, Ontario) and 60 mg of xylazine hydrochloride (Rompun'Symbol not transcribed'(C), Cutter Laboratories, Mississauga, Ontario) administered by a pre-loaded 3 ml Pneudart (Box 1415, Williamsport, Pennsylvania) fired from a Cap-chur dart rifle (Palmer Chemical Co., Douglasville, Georgia). The antagonist was 140 mg of naloxone (Narcan'Symbol not transcribed'(C), E.I. du Pont de Nemors, Glenolden, Pennsylvania), 4 mg of diprenorphine (M50-50'Symbol not transcribed'(C), Cyanamid, Montreal, Quebec) and 35 mg of yohimbine (Antagonil'Symbol not transcribed'(C), Janssen Pharmaceutica, Mississauga, Ontario).

All moose were rectally palpated to identify pregnancy status (Glover, 1985; Howard, 1986). Blood samples were also taken, and serum progesterone levels (P4) as well as pregnancy specific protein B (PSPB) were analysed (Wood et al., 1986) to confirm the results of rectal palpation. An incisor tooth was obtained from each moose and we later determined their ages by counting cementum annuli (Sargeant and Pimlott, 1959). A radio-collar (151 mHz, Telonics, Mesa, Arizona; Lotek Engineering, Aurora, Ontario; Telemetry Systems, Mequon, Wisconsin) was attached to each animal. To facilitate location of dead moose, all transmitters were equipped with a mortality sensor that was activated after eight hours of inactivity.

Moose were relocated monthly using a Helio-Courier fixed-wing airplane during the first five months of study and a Bell 206B helicopter subsequently. We attempted to sight each moose and determine the sex and age of any accompanying individuals. During the late May calving period, we relocated moose every two to four days to determine postnatal mortality. A calf was considered to be dead if it was not sighted during the intensive surveys in late May or during two consecutive monthly surveys. Twinning rates were calculated by dividing the number of all females that gave birth to twins by the total number of all females that gave birth. If a moose was found dead, the carcass remains and surrounding area were examined to determine probable cause of death (Larsen et al., 1989).

Home range sizes were calculated using the computer program HOME RANGE (Ackerman et al., 1990). Home ranges were described by the minimum convex polygon method (Mohr, 1947). The following time periods were used for analysis of seasonal home ranges: January-April (winter), May-August (summer), and September-December (autumn).

Survival rates of all females and calves were calculated using the staggered entry-by-month design (Pollock et al., 1989). The population was lightly hunted year-round by aboriginal hunters and seasonally by sport hunters. Since we requested that hunters avoid harvesting collared cows, mortality of females in general may have been slightly underestimated.

All means are presented with standard errors or ranges. The relationship between home range size and number of relocations was investigated by simple regression. Student's t-tests were used to compare home range size of moose studied for the entire three years versus those studied for less than three years as well as to compare post-calving movements of females that lost calves and those that retained calves. Seasonal home range sizes were compared by one-way ANOVA. Calf survival between years, early calf survival and twin survival were compared by means of 2 X 2 contingency tests (Sokal and Rohlf, 1969).

RESULTS

Capture and Relocation of Moose

In all, 32 females moose were radio-collared, 21 in November 1985 and 11 in November 1986. The average age of the collared moose was 6.5 yr. (range = 1.5-14.5 yr.). Two moose captured in 1985 died several days after capture. Since it was possible that this mortality was capture-related, they were excluded from the analysis. There were 48 relocation flights made during the three years and 1046 relocations were obtained on 30 moose. Visual sightings of the collared cows were made during 94% of these relocation flights. One moose was tracked for only seven months and was not included in the home range analysis.

Productivity

Pregnancy rates were 96% for adult females ( 2 yr., n = 27; Table 1) and 40% for yearlings (

Of the pregnant females that survived to the calving period, each spring an average of 86% gave birth. The mean calf:female moose ratio immediately after the calving period, over the three years, was 1.3:1. The twinning rate varied from 25% to 36% (Table 1), with a total of 17 sets of twins produced by 13 cows. Two females had twins in two successive years and one produced twins in all three years. The youngest female to have twins was two years old while another had twins at 13 years old. Calves (11.5 months old) were not found with their mothers in early May, two to three weeks before their mothers gave birth. They were occasionally observed within 0.5 km of the females after she gave birth.

Newborn calves were first observed on 22 May 1987, and 22 May 1988, and median dates of calving were 29 May (n = 10), 25 May (n = 20), and 28 May (n = 17) each year respectively. Only two calves were born later than 15 June. Distance between calving locations in successive years averaged 4.3 km (n = 15 moose; range = 1-11 km). Four of the 14 females (29%) collared for three years returned to 1 km of the same calving location during the three years. One females gave birth at the same location in 1986 and 1987 and then in 1988 had her calf 11 km from that location. Females that lost a calf in either May or June (n = 6) moved a mean distance of 23 km (range = 15-31 km) between the loss and the next relocation (approximately one month). These movements were greater than movements of females that retained their calves (p

Survival

Mean annual survival rate of the 30 female moose was 85 0.01% including hunting mortality and 880.02% excluding hunting mortality (Table 2). The cumulative survival rate for the three years was 62% and 70%, including and excluding hunting respectively. Five of eleven mortalities (45.5%) were fed upon heavily by wolves and most were likely a result of direct predation. Three moose mortalities (27.3%) were caused by hunting and three moose (27.3%) died from unknown causes. We observed extensive infections of hydatid cysts (Echinococcus granulosus) in the heart, lungs and liver and on the intestines of the three animals that died of unknown causes.

Calf Survival

Calf survival during the first eight weeks did not differ significantly between years (80% and 93%; p > 0.05). During the first six months post-partum (June-October), calf survival was slightly lower than that of the following six months (63% vs. 67%). Mean first year survival was 44 .06%. Excluding the five cases where calf mortality resulted after death of the mother, mean first year survival was 56%. Only 3 of the 17 (17.6%) sets of twins produced survived the first year together. The first-year survival rate for a calf with a twin (37%) was not significantly lower (p > 0.05) than that for a single calf (56%).

Home Range

Annual home ranges of collared moose overlapped considerably (Fig. 1). The home range of each collared moose overlapped those of at least two other collared moose. Home ranges varied considerably in size (Table 3: range = 40-942 km'Symbol not transcribed'2), but they were not significantly different in size between the 14 moose collared for the entire three years (20259 km'Symbol not transcribed'2) and 15 moose collared for three years or less (146 23km'Symbol not transcribed'2; p > 0.05). Mean range size for all moose (n = 29) was 17431 km'Symbol not transcribed'2 (mean relocations/moose=34). There was no significant relationship between the number of relocations and home range size (r'Symbol not transcribed'2=0.20, p > 0.05).

Home ranges were largest during autumn at 132215 km'Symbol not transcribed'2 (summer: 6835 km'Symbol not transcribed'2; winter: 5758 km'Symbol not transcribed'2) but we could not detect differences among seasons (p > 0.05). Wide variability in individual home range size contributed to the lack of difference among seasons.

DISCUSSION

The productivity of female moose in the Mackenzie Valley compared favourably with that of moose across North America (Boer, 1992). Their average pregnancy rate (96%) exceeded the North American average of 84% (Boer, 1992) and was higher than those reported from the Yukon (Larsen et al., 1989) and south-central and interior Alaska (Ballard et at., 1991; Gasaway et al., 1992). The average twinning rate (31%) was similar to both the North American average of 33% (Boer, 1992) and that of other northern boreal regions but lower than that observed in the southern boreal forest (Rolley and Keith, 1985). Mytton and Keith, 1981; Franzmann and Schwartz, 1985). Median calving dates were nearly identical to those observed in south-central Alaska (Ballard et al., 1991) and southern Yukon (Larsen et al., 1989) and more southerly areas (Hauge and Keith, 1981).

The average annual survival rate (hunting included) of female moose in the Mackenzie Valley (85%) was lower than that of hunted populations in south-central Alaska (95%) and southern Yukon (90%) (Larsen et al., 1989; Ballard et al., 1991). In more southerly regions of the boreal forest, it compared with the annual survival rates of female moose from a hunted population in Newfoundland (86%; Albright and Keith, 1987) and that of adults (males included) from an unhunted population in Alberta (84%; Mytton and Keith, 1981). It was higher than the annual survival rate for adult moose from a lightly hunted population in Alberta (75%; Hauge and Keith, 1981). Early (i.e., first eight weeks) and first year survival rates of calves were higher than those reported from Alaska and the Yukon, where predation was a major source of early calf mortality (Ballard et al., 1991; Gasaway et al., 1992). Mean first year survival of calves (44%) was approximately 30% higher in our study than that reported for other northern boreal regions (Larsen et al., 1989; Ballard et al., 1991). Albright and Keith (1987), however, estimated 69% annual calf survival in Newfoundland, where predator densities were low. Potential predators of calves, such as wolves, black bears and grizzly bears (see Gasaway et al., 1992), were present in the study area but at unknown densities. Furthermore, there were no alternate large prey (e.g., caribou, Rangifer tarandus) present in the study area. Under these conditions, some predation of calves would be expected (Gasaway et al., 1992). The greater movements of female moose immediately after losing a calf, as also reported by Ballard et al., (1991) and lower survival rates than where predators were few (Rolley and Keith, 1980; Mytton and Keith, 1981), were evidence that some predation of newborn calves occurred. However, mortality of calves during the first eight weeks in this study (14%) was low relative to the predation rates of 65% to 75% in Alaska and the Yukon (Larsen et al., 1989; Gasaway et al., 1992). Calculations based on an annual survival rate of 85% (including hunting), a birth rate of 86%, a 50:50 sex ratio at birth and an annual calf survival rate of 44% indicate that the female cohort would be increasing at 4% annually.

Female moose in the present study had total home ranges and seasonal ranges 2.5 times larger than the "adjusted" ranges of nonmigratory moose reported by Ballard et al. (1991) from a latitudinally similar area in south-central Alaska (Table 4). In calculating the adjusted home ranges, Ballard et al. (1991) excluded the large areas of terrain (e.g., lakes, glaciers, high ground) which moose cannot use. Such terrain was not a factor in the near-continuous forest of the Mackenzie Valley. Average home range size of female moose in the Mackenzie Valley was smaller than average home range size of migratory moose in south-central Alaska (van Ballenberghe, 1977; Ballard et al., 1991). However, female moose in the study area were not migratory. They contracted and expanded their movements seasonally, which resulted in partial overlap between seasonal ranges. As in other areas, they appeared to be least mobile during winter and most mobile during fall (Risenhoover, 1986; Ballard et al., 1991). As discussed by Cederlund and Okarma (1988), uniformity of elevation and habitat homogeneity are more likely to result in a resident moose population than is more rugged terrain, which is subject to greater habitat and climatic variations (e.g., snowfall). The home ranges of female moose in the Mackenzie Valley were also considerably larger than those reported for nonmigratory moose elsewhere in North America and in Europe (Table 4). In those areas, moose densities were considerably higher than in the present study area. The large individual home ranges may indicate that forage abundance was lower than in many other regions in western and northern North America (Mace et al., 1984; Risenhoover, 1986).

Low density of moose in the Mackenzie Valley and home ranges larger than any reported previously for A. a. andersoni suggest these moose are likely not sensitive to the scattered and localized industrial activity that the area will probably experience in the foreseeable future. However, new access into previously remote areas by means of both winter and all-season roads that accompany such activity poses the greatest management concern. Moose management in the Northwest Territories should emphasize the control of hunting when new access, especially through important winter feeding areas, may expose moose to possible overharvest.

ACKNOWLEDGEMENTS

Pilots L. Hill, Canadian Helicopters and W. Wright, North-Wright Air provided excellent flying during aerial relocation of moose and their continued enthusiasm was greatly appreciated. K. Jingfors, formerly of the N.W.T. Department of Renewable Resources, initiated this study and deployed the first radio collars. R. Bullion and K. John assisted with the field work in numerous ways. W. Ballard, D. Larsen, J. Nagy, C. Shank and A. Veitch provided valuable criticism of earlier drafts.

REFERENCES

Ackerman, B.B., Leban, F.A., Samuel, M.D., and Garton, E.O. 1990. User's manual for program HOME RANGE. Second edition. Technical Report 15, Contribution 259. Forestry and Wildlife Experimental Station, University of Idaho.

Addison, R.B., Williamson, J.C., Saunders, B.P., and Fraser, D. 1980. Radio-tracking of moose in the boreal forest of northwestern Ontario. Canadian Field-Naturalist 94:269-276.

Albright, C.A., and Keith, L.B. 1987. Population dynamics of moose, Alces alces, on the south-coast barrens of Newfoundland. Canadian Field-Naturalist 101:373-387.

Ballad, W.B., Whitman, J.S., and Reed, D.J. 1991. Population dynamics of moose in south-central Alaska. Wildlife Monographs 114.

Boer, A. 1992. Fecundity of North American moose (Alces alces): A review. Alces supplement 1:1-7.

Cederlund, G.N., and Okarma. H. 1988. Home range and habitat use of adult female moose. Journal of Wildlife Management 52:336-343.

Doerr, J.G. 1983. Home range size, movements and habitat use in two moose (Alces alces) populations in southeastern Alaska. Canadian Field-Naturalist 97:79-88.

Franzmann, A.W., and Schwartz, C.C. 1985. Moose twinning rates: A possible population condition assessment. Journal of Wildlife Management 49:394-396.

Gasaway, W.C., DuBois, S., Reed, D., and Harbo, S. 1982. Estimating moose population parameters from aerial surveys. Biological Papers of the University of Alaska, Number 22.

Gasaway, W.C., Boertje, R.D., Grangaard, D.V., Kelleyhouse, D.G., Stephenson, R.O., and Larsen, D.G. 1992. The role of predation in limiting moose at low densities in Alaska and Yukon and implications for conservation. Wildlife Monographs 120.

Glover, G.J. 1985. Aspects of the reproductive physiology of female wapiti. M.Sc. thesis. Faculty of Graduate Studies, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.

Hare, K.F., and Ritchie, J.C. 1972. The boreal bioclimates. Goegraphical Review 62:33-365.

Hauge, T.M., and Keith, L.B. 1981. Dynamics of moose populations in northeastern Alberta. Journal of Wildlife Management 45:573-597.

Howard, J.L. 1986. Current veterinary therapy in food animal practice. Second edition. Toronto: W.B. Saunders Company.

Larsen, D.G., Gauthier, D.A., and Markel, R.L. 1989. Causes and rate of moose mortality in the southwest Yukon. Journal of Wildlife Management 53:548-557.

Lynch, G.M., and Morgantini, L.E. 1984. Sex and age differential in seasonal home range size of moose in north-central Alberta, 1971-1979. Alces 20:61-78.

Mace, G.M., Harvey, P.H., and Clutton-Brock, T.H. 1984. Vertebrate home-range size and energetic requirements. In: Swingland, J.R., and Greenwood, P.J., eds. The ecology of animal movement. Oxford: Oxford University Press. 32-53.

Mohr, C.O. 1947. Table of equivalent populations of North American small mammals. American Midland Naturalist 37:223-249.

Mytton, W.R., and Keith, L.B. 1981. Dynamics of moose populations near Rochester, Alberta, 1975-1978. Canadian Field-Naturalist 95:39-49.

Phillips, R.L., Berg, W.E., and Siniff, D.B. 1973. Moose movement patterns and range use in northwestern Minnesota. Journal of Wildlife Management 37:266-278.

Pollock, K.H., Winterstein, S.R., Bunck, C.M., and Curtis, P.D. 1989. Survival analysis in telemetry studies: The staggered entry design. Journal of Wildlife Management 53:7-15.

Risenhoover, K.L. 1986. Winter activity patterns of moose in interior Alaska. Journal of Wildlife Management 50:727-734.

Rolley, R.E., and Keith, L.B. 1980. Moose populations and winter habitat use at Rochester, Alberta, 1965-1979. Canadian Field-Naturalist 94:9-18.

Sargeant, D.E., and Pimlott, D.H. 1959. Age determination in moose from sectioned incisor teeth. Journal of Wildlife Management 23:315-321.

Sokal R.R., and Rohlf, F.J. 1969. Biometry. San Francisco: W.H. Freeman and Company.

van Ballenberghe, V. 1977. Migratory behavior of moose in southcentral Alaska. Transactions of the International Congress of Game Biology 3:103-109.

Wood, A.K., Short, R.E., Darling, A., Dusek, G.L., Sasser, R.G., and Ruder, C.A. 1986. Serum assays for detecting pregnancy in mule and white-tailed deer. Journal of Wildlife Management 50:684-687.

Footnotes:

(f.1) Department of Renewable Resources, Inuvik, Northwest Territories X0E 0T0, Canada; present address: General Delivery, Yellowknife, Northwest Territories, X1A 2L8, Canada.

(f.2) Department of Renewable Resources, Norman Wells, Northwest Territories, X0E 0V0; present address: Canadian Wildlife Service, Box 637, Yellowknife, Northwest Territories, X1A 2N5, Canada. Offprint requests to P.B. Latour.

(f.3) Department of Renewable Resources, Inuvik, Northwest Territories, X0E 0T0, Canada; present address: Science Institute of the Northwest Territories, Inuvik, Northwest Territories X0E 0V0, Canada.

(f.4) Department of Renewable Resources, Norman Wells, Northwest Territories X0E 0V0, Canada.

(f.5) Assiniboine Park Zoo, Winnipeg, Manitoba R3P 0R5, Canada

(C) The Arctic Institute of North America

TABLE 1. Productivity of adult female moose ( 2 yr.) in the western Northwest Territories.

Year % Pregnant Total females Calves Calf/female Twin

(November) with calves produced ratio rate(%)

1986 96 10 13 1.3:1 33

1987 96 18 24 1.3:1 33

1988 - 14 19 1.4:1 36

1989(f.1) - 12 15 1.3:1 25

Total 54 71 Mean 1.3:1 32

(f.1) One relocation flight made for calf survival determination in June 1989.

TABLE 2. Annual survival of female ( 1.5 yr.) and calf moose in the western Northwest Territories.

Year Adults Calves

Hunting included Hunting excluded

1985-86 0.85 0.85 -

1986-87 0.82 0.93 .40

1987-88 0.87 0.87 .48

Mean 0.85 0.88 .44

Cumulative (1985-88) 0.62 0.70

TABLE 3. 100% minimum convex polygon home range sizes of 29 radio-collared

female moose in the western Northwest Territories.

Moose 100% polygon (km'Symbol not Number of relocations

transcribed'2)

1(f.1) 102 49

2 54 13

3(f.1) 205 48

4(f.1) 156 48

5 66 30

6(f.1) 71 48

7(f.1) 113 46

8(f.1) 174 33

9(f.1) 95 45

10(f.1) 145 45

11 90 18

12(f.1) 229 42

14(f.1) 942 48

16(f.1) 202 44

17(f.1) 59 47

18 140 15

19(f.1) 128 42

20(f.1) 210 49

21 150 18

22 131 34

23 40 20

24 102 34

25 70 16

26 337 34

27 208 34

28 88 34

29 249 22

30 226 34

31 248 20

(f.1) indicates moose radio-tracked for the entire study period (3 years).

TABLE 4. The mean home range sizes (minimum convex polygon) for adult moose in North America and Europe as determined by telemetry.

Location Mean home Number

range size of

(km'Symbol not moose

transcribed'2)

Northwest Territories 174 29

South-central Alaska 81(f.1) 13

Northwestern Ontario 43 5(f.2)

Northern Alberta 97 10(f.2)

Central Alberta 39(f.3) 177

Minnesota 10 22(f.2)

Sweden 13 14

Southeast Alaska 40 14

Table continued...

Location Density Source

(moose/km'Symbol not

transcribed'2)

Northwest Territories 0.16 this study

South-central Alaska 0.71 Ballard et al., 1991

Northwestern Ontario - Addison et al., 1980

Northern Alberta 0.18 Hauge & Keith, 1991

Central Alberta 1.20 Lynch & Morgantini, 1984

Minnesota 1.00 Phillips et al., 1973

Sweden >1.00 Cederlund & Okarma, 1988

Southeast Alaska 2.30 Doerr, 1983

(f.1) adjusted for null habitats (290 km'Symbol not transcribed'2 without adjustment).

(f.2) both females and males.

(f.3) the largest seasonal range (winter).

Figure not transcribed Consult original publication

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