Gray SJ, Hurst JL
School of Biology, University of Nottingham, U.K.
Anim Behav. 1998 Nov;56(5):1291-1299. doi: 10.1006/anbe.1998.0890.
Because of the cryptic nature of small mammals inhabiting vegetation with widely scattered food resources, little is known about the behavioural mechanisms underlying their spatial dispersion. While house mice exploiting human-built environments attempt to exclude intruders aggressively from small territories that contain concentrated food resources, comparative tests show that the grassland mouse, M. spretus, establishes dominance relationships and then avoids sites used by dominant competitors, probably to avoid displacement from sites that provide safety from predators. We carried out further comparative tests to examine competitive behaviour and response to odours from same-sex conspecifics among house mice living ferally on the Isle of May, U.K., using recently captured adult males (N=62) and females (N=23). In contrast both to house mice caught from buildings and to the grassland M. spretus, feral house mice from the Isle of May showed no aggressive, defensive or cautious behaviour on meeting a same-sex conspecific, with the exception of one aggressive male. Scent marks had no effect on their response to a competitor, although intruders in a scent-marked arena showed a significant sex difference in choice between a clean nest site versus one soiled by a same-sex resident: males spent more time in the soiled nest while females spent more time in the clean one. We propose that the lack of aggression among feral May mice may be due to the infeasibility of defending large territories, containing scattered resources, on an island where there is no real predation risk. We suggest that this hypothesis may explain the lower aggression and higher densities that are characteristic of populations of small mammals, reptiles and birds living on small islands. Copyright 1998 The Association for the Study of Animal Behaviour.
由于小型哺乳动物栖息在食物资源广泛分散的植被中，其行为隐秘，我们对其空间分散背后的行为机制知之甚少。虽然利用人类建造环境的家鼠会试图将入侵者从包含集中食物资源的小领地中积极驱逐出去，但比较试验表明，草原小鼠（西班牙小鼠）会建立优势关系，然后避开优势竞争者使用过的地点，这可能是为了避免从提供躲避捕食者安全场所的地点被赶走。我们进行了进一步的比较试验，以研究在英国梅岛野生生活的家鼠中，同性同种个体之间的竞争行为和对气味的反应，使用的是最近捕获的成年雄性（N = 62）和雌性（N = 23）。与从建筑物中捕获的家鼠以及草原西班牙小鼠不同，梅岛的野生家鼠在遇到同性同种个体时，除了一只具有攻击性的雄性外，没有表现出攻击、防御或谨慎行为。气味标记对它们对竞争者的反应没有影响，尽管在有气味标记的场地中的入侵者在干净巢穴与被同性居住者弄脏的巢穴之间的选择上存在显著的性别差异：雄性在弄脏的巢穴中花费更多时间，而雌性在干净的巢穴中花费更多时间。我们认为，梅岛野生家鼠缺乏攻击性可能是由于在一个没有真正捕食风险的岛屿上，保卫包含分散资源的大领地是不可行的。我们建议，这一假设可能解释了生活在小岛上的小型哺乳动物、爬行动物和鸟类种群所具有的较低攻击性和较高密度的特征。版权所有1998动物行为研究协会。
