| 文件类型： |
文章 |
| 所有的著者/提供者： |
Eldon H Bruns |
| ISSN: | 0022-541X |
|---|
| OCLC号码： |
479957701 |
| 语言注释： |
English |
| 注意： |
Fig. 1. The mean location of 4 pronghorn herds. The small circles enclosed by rectangles represent the means of herd positions. The rectangles include ± one SD of latitude and longitude. |
| 奖励： |
|
摘要：
The winter behavior of pronghorn antelopes (Antilocapra americana) was studied from 6 January to 12 April 1969 in southeastern Alberta and northern Montana. January, climatically an exceptionally severe month in the study area, saw a pronounced movement of pronghorns southward. The mean herd size was 39.8 ± 11.5 head. Herds did not mix, nor move more than a few km from local sites during February and March; a distinct disbanding process was noted after 25 March. Fences and roads limited day to day movements. Herd composition counts for 6 herds (221 head) indicated a low fawn proportion (41 fawns to 100 does). The male to female fawn ratio of 42 to 100 indicated poor production or survival of male fawns. Pronghorns were adept at pawing away snow cover to reach their food. They spent 6.2 to 11.5 percent of their feeding time pawing. Interactions at feeding craters and bedding sites indicated a social heirarchy with male adults at the top, followed by female adults, and fawns. Pronghorns selected microhabitats with more favorable conditions than the average for the area as a whole, these being: 63 percent lower wind velocities, 24 percent less snow, and 87 percent softer snow. The daytime activity pattern began with a feeding period shortly after sunrise. Resting animals oriented the longitudinal axis of the body so that their anterior portions were downwind when chill factors were extreme; they also curled their heads alongside the body more often at lower chill factors.
引证/输出
预览资料
文章 : 英语