高原鼠兔领域行为时间分配格局及其对风险环境适应的探讨

Time Allocation of Territorial Activity and Adaptations to Environment of Predation Risk by Plateau Pikas

采用直接观察法测定了高原鼠兔地面、洞道活动时间及进、出洞频率.结果表明,在07:00～18:00,雄性和雌性高原鼠兔平均地面活动时间分别占总活动时间比例的87.09%和85.22%.地面活动时间具有明显的季节性,但两性个体间无显著的差异.繁殖早期,成年雌体地面活动时间显著高于繁殖后期,第2胎幼体地面活动时间显著低于第1胎幼体.不同年龄和性别的高原鼠兔进洞频率存在极显著差异,5月成年雌体进洞频率最高,而成年雄体在4月进洞频率最低.研究结果验证了捕食风险可制约鼠兔属动物领域活动时间分配,高风险环境能增加其利用洞道的时间及频率的特定假设.

Time allocation of activities on the surface and in burrows, and the frequencies of entering and emerging from burrows were compared by age and gender in plateau pikas （ Ochotona curzoniae ） using directly observations in the field. The results showed that from 07： 00- 18：00 males spent 87.09% and females spent 85.22% of total time on the surface. Although there were no significant gender differences in time spent on the surface, significant seasonal variations were found. In the early breeding season, adult fenmles spent more time on the surface than they did during the later breeding season. The juveniles of the second litter spent much less time on the surface than did those of the first litters. The frequencies of burrow entering differed significantly depending on age and gender in the pikas. The highest burrow entering frequency was found in May for female adults, whereas, the lowest in April for male adults. Our results provide evidence to support the hypothesis that predation risk can restrain the territorial activity and time allocation and that living in a high risk environment will facilitate utilization of burrows by small mammals.