小型啮齿动物种群系统调节复合因子理论的野外实验研究：食物可利用性和捕食对根田鼠种群空间行为的作用模式及其对种群调节的探讨

本项研究在野外围栏条件下，采用析因实验设计，测定食物可利用性和捕食对根田鼠（Ｍｉｃｒｏｔｕｓｏｅｃｏｎｏｍｕｓ）种群空间行为的作用模式。检验的特定假设为，高质量食物较大的可利用性能降低田鼠的攻击行为和活动；捕食能减少田鼠的活动。研究结果表明，食物可利用性能间接地和直接地影响根田鼠的空间行为。附加食物种群具有较高的密度和较小的巢区，且在诱捕期间具有较少的长距离活动和较低的攻击水平。捕食者的存在不直接影响攻击行为，但能影响诱捕期间的长距离活动，此为根田鼠对捕食者存在作出的直接反应。在阐明田鼠种群动态时，应仔细考虑上述因子相互作用的效应。

FIELD EXPERIMENTAL STUDIES ON THE MULTIRACTORIAL HYPOTHESIS OF POPULATION SYSTEM REGULATION FOR SMALL ROCENTS:THE EFFECT PATTERN OF FOOD AVAILABILITY AND PREDATION ON SPACING BEHAVIOUR OF ROOT VOLES AND THE FUNCTION OF SPACING BEHAVIOUR IN POPULATION REGU

The effect pattern of food and predation on spacing behaviour of root voles(Microtus oeconomus)reported in this paper is one part of the multifactorial hypothesisof population regulation for small rodents,The two specific hypotheses tested are:1)greater availability of high quality food reduces aggression and movement of root voles;and 2)exposure to predators reduces movement of root voles.The results showed that food availability could act directly or indirectly on spacingbehaviour of root voles.Mean densities increased and mean home range size decreased inpopulations with supplemental food.Food acted indirectly on home range size via theeffect of food on population density. Compared with other treatments,voles withsupplemental food were less aggressive toward one another and showed fewer longmovements between trapping sessions,Exposure to predation did not affact aggressionamong voles,but it appeared to reduce long movements between trapping sessions. Thisreduced long movement was probably a direct behavioural response of voles to thepresence of predators. We conclude that factors extrinsic to the vole populations caninfluence behaviour directly or indirectly. Such interactions should be consideredcarefully when explaining the population dynamics of voles.