Antelope 



Population characteristics : During the six season study, 1784 

 antelope were observed in the Otter Creek study area (Table 9). 

 Average group size ranged from a low of 3.0 in spring 1979 to 

 a high of 18.4 during the winter months. January, in the dead 

 of winter, recorded 25.7 antelope per group. Dispersal from 

 winter herds occurred in April as the group size decreased 

 from 13.4 in March to 5.0 antelope per group in April. 



Antelope were most easily spotted in December and February 

 when over 91 antelope were observed per hour of aerial survey 

 (Table 2). This is when the antelope are concentrated in large 

 groups. Many antelope appeared to have left the Otter Creek area 

 during January. The total number observed from the air, 77, 

 was considerably below the 200 plus numbers observed in December 

 and February. Perhaps this area represents marginal wintering 

 habitat for antelope. High numbers per hour were also observed 

 in July and August. This corresponds to the tine frame when 

 antelope numbers should be at their seasonal peak just shortly 

 after fawn recruitment. 



Production figures and population structure percentages are 

 shown in Table 10. August data in 1979 show 64.4 fawns 

 per 100 does. This compares to 68 and 59 fawns per 100 

 females in Fish, Wildlife and Parks hunting units 740 and 741 

 in 1978 and 1977 respectively, the latest year in which surveys 

 were conducted (Wentland 1979). June of 1980 saw the percentage 

 of fawns in the population remain stable at slightly over 20 

 percent, while the number of fawns per 100 does increased from 

 33.3 to 40.0 over June of 1979. The percentage of bucks was 

 28.9 in June of 1980, slightly lower than the average of 30.7 

 recorded for hunting unit 740 since 1963 (Wentland 1979) » 



Distribution : Antelope spring distribution is shown in Figure 11. 

 There appears to be four widely scattered groupings of antelope 

 observations. One is located on either side of Cook Creek north 

 of highway 212. Another stretches along the southwest side of 

 Otter Creek north of the Custer National Forest, This group 

 appears to have the second largest number of sightings. Another 

 group is found astride Threemile Creek on the eastern edge of 

 the study area. The greatest number of observations occurred 

 in the southern portion of the study area with Newell Creek as 

 its approximate northern boundary. 



Many antelope are still in large herds at this time exhibited 

 by the number of group sightings in the 9-15 and over 15 

 categories . 



During the summer months (Figure 12), antelope were more dispersed 

 than during spring. The four groupings mentioned above seemed to 



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