A survey during 1977 found that the Gateshead Island area, Northwest Territories, had 9 confirmed and 10 suspected polar bear dens. The importance of the area for polar bear reproduction was confirmed during a survey in 1982 when 15 dens were found, 10 of which were identified as maternity dens. The area should be protected from human intrusion.Key words: polar bears (Ursus maritimus), denning, reproduction, Gateshead Island, Northwest TerritoriesMots cl&eacute;s: ours blancs (Ursus maritimus), tani&egrave;res, reproduction, l'&icirc;le Gateshead, Territoires du Nord-Oues

Schweinsburg, R.E.

Spencer, W.

Williams, D.

English

University of Calgary Journal Hosting

ARCTIC VOL. 37, NO. 2 (JUNE 1984) P. 188.171 Polar  Bear  Denning  Area  at  Gateshead  Island, Northwest  Territories R.E. SCHWEINSBURG’, W. SPENCER’, and D. WILLIAMS Polar bears (Ursus maritimus) give birth during midwinter in maternity dens dug into snowdrifts (Harington, 1968). The protection provided by the den ensures maturation of the cubs until they are sufficiently developed to follow their mothers. Since denning is necessary for polar bear reproduction, man- agement agencies have spent considerable time searching for and  then protecting maternity denning areas. This is par- ticularly important in Canada because of the potentially dis- ruptive industrial developments proposed within polar bear denning areas. In Canada, important denning areas have  been  found  along the  western shore of Hudson Bay (Jonkel et al., 1972). on the Simpson Peninsula, on southeast Baffin  Island  (Jonkel et af., 1978), and on Southampton Island (Harington, 1968). How- ever, in most  places in the Canadian Arctic Archipelago, maternity den sites are scattered, probably because of the availability of widespread and abundant denning habitat (Stir- ling et al.,  1978). There have  been  no reports of denning areas that equal the density  found  on Wrangel Island (Uspenskii and Kistchinski, 1972) or Svalbard (Larsen, in press). This paper reports on an important denning area on Gateshead Island, Northwest Territories, Canada. Gateshead Island is located  at  the south end of M’Clintock Channel (Fig. 1). The island covers about 260 km2 and  is  flat with a maximum elevation of 41 m. Several smaller islands lie near Gateshead. The largest of these is Tinguayalik Island (30 k m 2 )  about 25 km to the southwest (Fig. 1). The area is ice-covered most  of  the year although the  ice  is unconsolidated during the warmest months. The prevailing surface current is northwesterly, through M’Clintock Channel (Collin, 1958). Helicopter tagging studies (Schweinsburg et af., 1981) showed that the Gateshead Island area was a concentration area for  all ages of bears, but  no dens were  found during the tagging operations. However, it was suspected that denning occurred on the islands because the east coast of Victoria Island, the nearest land, is flat and unsuitable for denning. Since Inuit, particularly David Kaomayok, reported denning on Gateshead Island, a ground survey was initiated in 1977 and  again in 1982 to determine the importance of the Gateshead  Island area to polar bears. Observations of bear dens were made from snowmachines (Kiliaan et al.,  1978) during 7-20 April  1977  and 5-14 April 1982. Four days were spent searching for dens during 1977 and eight during 1982. Incidental observations were  made dur- ing travelling days on  both surveys. Dens were found by searching the land areas for mounds of excavated snow (“porches” - Harington, 1968) that were clearly visible in the  flat terrain with either the naked eye or binoculars. Once a den was located, a 2-m steel rod  was  used to probe the cavity. Dens that were not occupied were ex- cavated where possible and their characteristics recorded. Aspect, bear signs (tracks, urine stains, and scats), and  the ex- tent  of  icing  inside  the den, which  indicated duration of use, were recorded. Since most dens were abandoned at the time of the survey, presence and age of cubs in abandoned dens were determined from tracks. A maternity den was defined as one that  had evidence of cubs of any age. During 1977, nine of 19 suspected sites were positively identified as bear dens (Fig. I ) .  A storm during the survey buried many of the suspected dens under deep drifts which precluded positive identification or excavation. During 1982, 15 sites were found, all confirmed as bear dens. Only three of the dens found in 1977 were identified as maternity dens, compared to 10 in 1982 (Fig. 1). One of  the 13 maternity dens contained cubs older than newborn, either yearlings or two-year-olds. Because drifting snow obliterated tracks, the  number  of cubs in each den, and hence productivi- ty, could not be determined during either survey. Ten of the dens did  not contain cubs and  the occupancy of ‘Wildlife Management Division. Department of Renewable Resources, Government of the Northwest Territories, Yellowknife, N.W.T., Canada X IA 2L9 170 NOTES A Maternity d m  1977 Short  erm den 1977 a Unknown occupancy I977 H wtwnity den 1982 A short term den 1982 0 Long term dm 1982 """- a 0 I - K ~  I Denning sites on  Gateshead Island one den was not determined since a bear was still present within. Van de Velde (1957) and Harington (1968) reported denning of non-breeding bears of both sexes. The dens that  did not have cubs were probably used by non-breeding bears al- though the possibility of intra-uterine and post-parturn cub mortality in the  den exists. Dens of non-breeding bears can be used for varying lengths of time (Harington, 1968). In 1977, no long-term, non-maternity dens were found but three non- maternity dens found in 1982  had extensive icing on the  walls and ceilings, indicating lengthy occupancy. In both surveys, most  of  the dens were  located on  the eastern side of Gateshead Island (Fig. I ) .  Compared with the rest of the island, the terrain in this area is relatively  more  broken  and elevated providing more suitable habitat for denning polar bears. Most dens were found  within 1 km of the coast. During 1977, 17 of the proven and suspected dens had a southern exposure and two faced northwesterly, whereas in 1982, I O  dens faced northwesterly and the  remaining five northeasterly. Other authors found that dens generally face south (Harington, 1968; Uspenski and Kistchinski, 1972), but the selection of den sites is probably dependent upon  the amount of snow accumulated at  the  time  of denning. I n  the  fall of  1981  predominant southerly winds resulted in a snow build- up on north-facing slopes (David Kaomayok, pers. comm. 1982). This observation could explain the observed selection of north-facing  den sites on Gateshead Island during the 198 1-82 winter. Unfortunately, meteorological data are lack- ing for the Gateshead Island area. Since emergence from dens occurs over a month (Uspenski and Kistchinski, 1972), many abandoned dens are undoubtedly NOTES obliterated by storms. Therefore, we probably found only a portion of the dens that occurred in the area. Nevertheless, these  two  surveys  indicate that Gateshead  Island  and  the  near- by satellite  islands are important maternity denning areas for polar  bears  and  should be protected from human intrusion. ACKNOWLEDGEMENTS These surveys were financed by the N.W.T. Wildlife Service. Special  thanks go to  David  Kaomayok  whose  skills  in  arctic  travel  and knowledge  of polar bears made  these  surveys  uccessful.  Allen Kitigon, Ed Moniyogena,  Charles  Nakhook and James  Paniyoak  also helped  on  the  surveys.  Kent  Jingfors  helped  with  the  manuscript. REFERENCES COLLIN, A.E. 1958. An oceanographic study of Prince Regent Inlet, the Gulf of Boothia and the adjacent waters. Fisheries Research Board of Canada MS. Report Series No. 13. HARINGTON, C.R. 1968. Denning habits of the polar bear (Ursus muriri- m u  Phipps). Canadian Wildlife Service Report Series No. 5. 30 p. JONKEL, C.J., KOLENOSKY, G.B., ROBERTSON, R.J. and RUSSELL, R.H. 1972. Further notes on polar bear denning habits. In: Herrero, S. (ed.). Bears: Their Biology and Management. IUCN Publications, New Series 23. 142-185. JONKEL, C.J., LAND, E. and REDHEAD, R. 1978. The productivity of polar bears (Llrsus  maririmus) in the southeastern Baffin  Island area, Northwest Territories. Canadian Wildlife Service Progress Notes No. 91. KILIAAN, H.P.L., STIRLING, I .  and JONKEL, C.J. 1978. Polar bears in the area of Jones Sound  and  Norwegian  Bay. Canadian Wildlife Service Progress Note No. 88. 21 p. LARSEN. T. (In press). N.W. polar bear denning and oil production in Sval- bard. Journal of Wildlife Management. SCHWEINSBURG. R.E.. FURNELL. D.J. and MILLER. S.J. 1981. Abun- dance. distribution and population structure o f  polar bears in the lower central Arctic laland. N.W.T. Wildlife Service Completion Report #2. 80 p. STIRLING, I . ,  SCHWEINSBURG, R.E.. CALVERT, W. and KlLlAAN. H.P.L. 1978. Population ecology of the polar bear along the proposed Arctic Islands gas pipeline route. Final report to Environmental Manage- ment Service, Canada Department of Environment. 93 p. USPENSKI, S.M. and KISTCHINSKI, A.A. 1972. New data on the winter ecology  of  the  polar bear (Ursus madimus Phipps) on Wrangel Island. In: Herrero S. (ed.). Bears: Their Biology and Management. IUCN Publica- tions, New Series 23. 181-197. V A N  DE VELDE, F. 1957. Nanuk, kingofthe Arcticbeasts. Eskimo45:4-15. 7 P. 171 

Polar Bear Denning Area at Gateshead Island, Northwest Territories

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Polar Bear Denning Area at Gateshead Island, Northwest Territories

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