TRACKING WILDLIFE BY SATELLITE 



39 



during late summer and winter coincided with the peak 

 of the rut and spring migration, respectively (Fig. 34). 

 With further ground verification, the 24-h index was con- 

 cluded to be useful as a reflection of general activity levels 

 for male Dall sheep. 



Elk: Yellowstone National Park 



Elk study in Yellowstone National Park by D. Vales 

 focused on the social behavior and feeding strategies of 

 adult males, especially during winter. Vales placed PTT's 

 on a yearling male and a 10-year-old male in early Sep- 

 tember, just as the rut was beginning. The yearling elk's 

 collar was fitted loosely, to allow further growth. The 

 mature elk's collar was fitted tightly, with the expectation 

 that it would loosen after the rut. 



In addition to the information on general movements 

 desired by park managers, this study sought quantitative 

 data on behaviors during all times of day during winter and 

 further calibration of the short-term activity index for elk 

 (see Short-term Activity Index). Therefore, a duty cycle of 

 6 h of transmission every 50 h was chosen so that as many 

 times of the day as possible were sampled within each 

 4-week interval. This duty cycle deliberately spread infor- 

 mation throughout the 24-h day but resulted in fewer 

 locations. As expected, little information was gathered 

 during those periods of low overpass frequency (Fig. 35). 



As with the Kodiak Island bear study, substantial varia- 

 tion in the performance of the two PTT's was noted. From 

 deployment in mid-September 1987 through January 

 1 988, one PTT yielded 1 1 8 locations while the other yield- 

 ed only 49. However, unlike the Kodiak Island study, there 

 was no obvious relation between PTT performance and 

 topographic features or habitat selection (D. Vales, per- 

 sonal communication). Hours of transmission of the two 

 PTT's were identical, as were relative performances with 

 regard to time of day. The two collars showed no signifi- 

 cant difference in signal strength (P = 0.093, n = 27); 

 however, the transmitter that produced fewer locations 

 and poorer precision did have consistently lower signal 

 strength. Additionally, the motion detector in one of the 

 two PTT's malfunctioned during winter. During visual 

 observations of the instrumented animal, it was seen to 

 walk and feed while the 60-s activity index continued to 

 show only zero values. 



Movements of both elk were relatively restricted during 

 winter, when they remained primarily in the Gardiner and 

 Mammoth areas of the park (Fig. 36A). Because of the 

 high elevation of this area (1,640-2,300 m above sea 

 level), locations calculated assuming sea level displayed 

 considerable longitudinal error. When a correction that 



o 10 

 q 



Q 



| 4 







J F M A M J J ASOND 



Fig. 34. Annual changes in the 24-h activity index for a Dall 

 sheep ram in the Brooks Range, Alaska. Data courtesy of M. 

 Hansen, University of Alaska. 



8 40 

 co 



V) 

 03 

 Q- 30 



8 

 O 



Locations 



No locations 



(D 



.0 



E 



=3 



20 



10 



I 



18 20 22 2 4 6 8 10 12 14 

 Hour of Day (UT) 



Fig. 35. Daily pattern of data acquisition for two elk in Yellow- 

 stone National Park, September 1987-January 1988. Both 

 PTT's had duty cycles of 6 h on 44 h off, allowing sampling 

 during all hours of the day within each 25-day cycle. Data 

 courtesy of D. Vales, University of Idaho. 



assumed an average elevation was used, it yielded move- 

 ment patterns much closer to those known from ground 

 telemetry and visual locations (Fig. 36B). 



Mule Deer: Southeastern Idaho 



As part of a larger study, game biologist C. Brown 

 deployed four PTT's on adult female mule deer just before 

 the hunting season in 1987. The primary objectives were 

 to obtain movement data during the hunting season and 

 just afterwards to judge whether cover use and behavior 

 patterns differed between those times. Two deer were 

 fitted with 1 .6-kg second-generation PTT's, and two were 



