34 



FISH AND WILDLIFE TECHNICAL REPORT 30 



having to search large areas for them. However, greater 

 reliability of PTT's deployed on polar bears is necessary 

 for these studies to be feasible. 



Polar Bear: Chukchi Sea and Bering Sea 



Satellite telemetry is being used in the Chukchi Sea and 

 the Bering Sea to define the seasonal movement patterns 

 and total area used by polar bears. The bears occur sea- 

 sonally in Alaskan waters but also spend time in waters 

 under jurisdiction of the Soviet Union, where aerial sur- 

 veys required by conventional telemetry are not permitted. 

 Using satellite telemetry data, we have found that as the 

 sea ice retreats from the Chukchi Sea, polar bears also 

 retreat into Soviet waters and often spend summer in the 

 vicinity of Wrangel Island. When the sea ice advances in 

 fall, polar bears again move into U.S. waters. 



To satisfy study objectives, we have attempted to recol- 

 lar individual female bears when they return to U.S. wa- 

 ters. This effort has met with only partial success, because 

 some PTT's have failed prematurely and because some 

 bears have denned while in Soviet waters or territory and 

 did not return to U.S. waters during the PTT's battery life. 

 In an attempt to extend battery life through a second 

 spring capture season, we have experimented with altering 

 duty cycles. However, the success of this experiment is not 

 yet determined. 



The longevity of PTT's seems to be improving, as does 

 the potential of the saltwater switch for further interpreting 

 the polar bear-sea ice relation. Satellite telemetry is cur- 

 rently the only methodology available for addressing sev- 

 eral of the major objectives of the western polar bear 

 project. 



Muskox: Arctic Slope 



Muskoxen were reintroduced to the coastal plain of the 

 ANWR in 1969 and 1970. Muskoxen have been radio- 

 collared since 1982 to document distribution and move- 

 ments of the population (Reynolds 1987). The animals 

 display high fidelity to specific geographic areas and re- 

 main year round on the coastal plain. Data on distribution, 

 movements, and activity patterns of muskoxen in winter 

 are needed to assess potential effects of petroleum devel- 

 opment. Such information has been particularly difficult 

 to obtain with conventional radiotelemetry because of 

 darkness, blowing snow, and other adverse weather condi- 

 tions on the arctic coastal plain during winter. 



In 1984, a first-generation satellite collar was deployed 

 on a muskox in ANWR to test how the collar functioned 

 (Reynolds 1989). In November 1986, two cow muskoxen 

 were collared with third-generation satellite collars. 

 One collar failed almost immediately but was repaired 



and refurbished and placed on another cow muskox in 

 July 1987. The second collar transmitted for 6 months 

 until the muskox was killed; it was then placed on 

 another cow in July 1987 without being refurbished. 

 Both collars have been functioning for almost one 

 year. They were programmed to provide intensive sam- 

 pling periods at 12- week intervals during which they 

 transmitted 16 h/day for 5 days. During the remainder of 

 the year, collars transmitted 6 h/day every third day. A 

 third satellite collar, with a duty cycle of 6 h/day every 

 other day, was deployed on a cow muskox from October 

 1987-April 1988. 



Preliminary analysis of movement data from one ani- 

 mal during 1986-87 and three animals during 1987-88 

 indicated that muskoxen have small home ranges and 

 move only short distances during the darkest, coldest 

 months of winter (Fig. 30). 



Muskox: Greenland 



In July 1987, two third-generation PTT's were put onto 

 adult male muskoxen in the Kap Kobenhavn area in Peary 

 Land, northern Greenland (82.5 N, 22.5 W), as part of a 

 cooperative study with D.R. Klein, ACWRU. The collars 

 were deployed to provide data on muskoxen activity at 

 high latitudes for comparison with data from muskoxen 

 populations at lower latitudes. The study area is a high 

 arctic polar desert with most vegetation limited to sedge- 

 grass and willow communities in scattered locations 

 where meltwater is available throughout summer. As with 

 the ANWR muskox study, logistical problems in winter 

 made data collection by other means impractical. Trials 

 with captive muskoxen and various orientations of the 

 PTT's mercury tip-switch were not able to accurately dif- 

 ferentiate muskoxen behaviors using the simple mercury 

 tip-switch. However, a tip-switch orientation was chosen 

 that seemed capable of providing a measure of active- 

 versus-inactive time for muskoxen in northern Greenland 

 for comparison with data from other muskoxen 

 populations. 



The two PTT's were programmed to transmit for a 6-h 

 period during each 5 1 h. Then, the beginning of the 6-h 

 period was shifted 3 h later every two days, so that all 

 hours of the day would eventually be sampled. The first 

 transmissions from the two transmitters were received on 

 7 July 1987. One transmitter provided locations and tem- 

 perature data at least through July 1988, but the activity 

 sensor malfunctioned in mid-October. The second PIT 

 provided location and activity data for approximately 2 

 weeks, after which no transmissions were received for > 7 

 months. For 3 days beginning 15 March 1988 and spo- 

 radically since then transmissions from this second PTT, 

 including short-term activity data, were again received. 



