不同种群密度下高原鼠兔的行为模式

Behavior patterns of plateau pika Ochotona curzoniae at different population densities*

在2003年高原鼠兔(Ochotonacurzoniae)的繁殖初期、繁殖盛期、繁殖中期和繁殖末期,采用目标动物取样法对其不同种群密度条件下的行为模式进行研究,探讨高原鼠兔的行为变化和种群密度的相互关系。结果表明:在繁殖盛期和繁殖中期,低密度种群内雌性高原鼠兔的观望时间均显著高于高密度种群内,而在其它两个时期内无明显不同;雄性高原鼠兔的观望时间在不同密度间比较均无显著差异;同一密度条件下,雄性高原鼠兔的观望行为持续时间和发生频次均表现显著的季节性变化,而雌性高原鼠兔无明显差异。高原鼠兔的地面活动时间在不同种群密度间比较无显著差异。低密度种群内,雄性高原鼠兔的地面移动距离和频次均呈显著的季节性差异,而雌性高原鼠兔的差异不显著;高密度种群内,雌、雄个体的地面移动距离和频次都具有显著的季节性差异。在高原鼠兔的社会行为中,亲昵行为和攻击行为强度在不同种群密度间比较均无显著差异;在同一密度条件下,亲昵行为和攻击行为强度也没有表现出明显的季节性变化。以上结果说明高原鼠兔的行为变化与其繁殖期和性别有明显的关系,而在密度间无明显的差异,其主要原因是在不同的繁殖期,动物的繁殖投入不同。

We investigated the behavior of plateau pika Ochotona curzoniae in populations of different density in 2003, using focal-animal sampling technique during the reproductive season, which included early stage, peak, middle and later stage of reproduction. Significant differences were shown in the observation times of females during the peak and the middle of the reproductive season at different densities. The observation time of the females was much longer in low density population than that in high density population. For males, there was no significant difference in observation time between or among population densities. At both low and high population densities significant seasonal variation was found in the duration and frequency of male plateau pikas＇ observation behavior, nor was that of females. There was no significant difference in surface activity times between or among populations of different density. No significant seasonal variation was observed in moving distance and moving frequency of female plateau pikas in low density population, whereas moving distance and frequency varied significantly for males. Significant seasonal variations were shown in both females and males in high density populations. No significant seasonal differences were observed in plateau pikas＇ aggressive and affiliative behaviors from either low or high density populations. Additionally, no significant differences existed between populations with different densities. This indicated that the behavior patterns of plateau pika were affected by the reproductive period and gender but not by population density. We concluded this behavioral variation was evoked by the different reproductive investments among different reproductive periods [Acta Zoologica Sinica 51 （4） ： 598 - 607, 2005].