草原田鼠和草甸田鼠波动种群雌鼠的攻击性

本文比较研究了草原田鼠和草甸田鼠自然种群在不同密度周期时相雌鼠攻击水平的变化。结果表明, 不同密度时相, 草原田鼠种群中攻击雌鼠所占比例以及接近、威胁、进攻、退避, 进攻/ 接近等5 种行为变量均无显著的差异, 5 种行为变量与种群密度亦均不呈显著的线形相关关系。然而, 草甸田鼠在不同密度时相攻击雌鼠的比例差异显著。低密度时相, 雌鼠发生威胁行为的平均次数显著高于上升和衰减时相, 进攻行为的平均次数亦显著高于其它时相。本研究结果不支持有关田鼠种群在一个完整的周期过程中具有多态性行为的假设。

Levels of Female Aggressiveness in Fluctuating Populations of Microtus ochrogaster and M.Pennsylvanicus

Levels of aggressiveness of females from free-living populations of Microtus ochrogaster and M.pennsylvanicus were compared during phases of the population cycle. M.ochrogaster displayed no significant difference in the proportion of aggressive females or in the means of five behavioral variables (approaches, threats,attacks,retreats,attacks/approaches) among phases of the population cycle. None of these variables showed a significant linear regression against population density. Neither did the proportions of aggressive M.pennsylvanicus females differ among phases. The mean number of threats in this species was significantly higher during the low than the increase and decline phases and the mean number of attacks was significantly higher during the low than all other phases.The results of this study are similar to those obtained for males and do not support the polymorphic behavior hypothesis regarding generation of population cycles in arvicoline rodents.