高原鼠兔间断性移动模式与反捕食对策分析

本文采用直接观测法, 测定了高原鼠兔地面移动频率及每次移动距离。结果表明, 高原鼠兔地面移动频率和每次移动距离依繁殖时期、年龄及性别而存在极显著的差异。繁殖早期, 成年雄体地面活动频率大于成年雌体。繁殖后期, 第1 胎雄性幼体大于同年龄的雌体。繁殖早期, 成年雌体地面活动频率高于繁殖后期, 而幼体与成体之间无显著的差异。繁殖初期雄体每次移动距离大于雌体, 其它时期雌、雄体之间则无明显的差别。雄体每次移动距离逐月降低。雌体每次移动距离无显著的季节性差异。研究结果进一步验证了暴露于风险环境中的植食性小哺乳动物, 主要采取间断性移动模式, 增加反捕食时间投入, 降低风险的假设。

Characteristics of Discontinuous Locomotion with Respect to Anti-predator Behavior of Plateau Pikas

We measured the frequency of locomotions above-ground and within burrows, as well as the distance of each movement, of plateau pikas (Ochotona curzoniae) using direct field observations. Locomotion rates and distances differed significantly by sex and age of pikas, as well as by month of the year. Prior to the breeding season, adult male pikas moved significantly more frequently above-ground than did females. Locomotion frequency of adult females was higher during the breeding period than after it. We observed no significant differences in locomotion rates of adults vs. juveniles during the breeding season. Males traveled greater distances during each locomotion than did females early in the breeding season, but no gender difference was observed during other time periods. Among males, distances traveled during each locomotion bout tended to decrease gradually from April to August. In contrast, we observed no discernible seasonal patterns among females. Our results were in accord with predictions that small herbivores living with high predation risk would adopt a discontinuous mode of locomotion and increase their investment in anti-predators behaviors.