Behavioral mechanisms of habitat segregation between sympatric species of Microtus: Habitat preference and interspecific dominance
Behavioral mechanisms of habitat segregation between sympatric species of Microtus: Habitat preference and interspecific dominance
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田鼠同域物种生境隔离的行为机制：生境偏好与种间优势
DOI：
10.1007/bf00294990
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发表时间：
1978
影响因子：
2.3
通讯作者：
J. Randall
中科院分区：
文献类型：
--
作者：
J. Randall
摘要两种田鼠啮齿动物在华盛顿东部同域分布，但它们因栖息地而分离。在草地中发现了高山田鼠M.长尾龙栖息在灌木丛中。本研究评估了控制分布的行为机制，并提出了以下问题：（1）一种或两种田鼠是否占据了首选的栖息地？(2)栖息地偏好是否受早期经验的影响？(3)一个物种会把另一个物种排除在栖息地之外吗？2.在室外围栏中进行的试验中，提供了天然灌木和草地栖息地之间的选择，两个物种都表现出对草地栖息地的偏好，而不管先前的经验如何。然而，M. montanus对草的亲和性比M.长尾的野捕（草）M.在草地生境中的时间显著多于野外（灌木）和草地饲养的时间（P<0.01）。3.早期的草地生活经历不是选择的先决条件，但草地生活经历增加了M. montanus，并减少了栖息地占用的变化（图1）。longicaudus响应早期暴露于灌木和草地栖息地减少栖息地占用的个体差异。与M.对montanus来说，这种经历并没有增加它们对这两种自然栖息地的亲和力。montanus雄性体型较大，在种间相遇中占主导地位。由于M.长尾猴具有从M. montanus。相比之下，M. montanus表现出低的戒断倾向（图2）。由于喜食草，因此可能只限于在草地上栖息。M. longicaudus似乎被排除在其首选的草栖息地，其倾向于退出占主导地位的M。montanus。
SummaryTwo species of microtine rodents are sympatric in eastern Washington, but they are segregated by habitat. Microtus montanus is found in the grass, and M. longicaudus occupies the shrub habitat. This investigation evaluated behavioral mechanisms controlling the distribution and asked the questions: (1) Are voles of either or both species occupying a preferred habitat? (2) Is a habitat preference influenced by early experience? (3) Does one species exclude the other from a habitat?2.In tests in outdoor enclosures that provided a choice between natural shrub and grass habitats both species exhibited a preference for the grass habitat, irrespective of prior experience. However, M. montanus exhibited a stronger grass affinity than M. longicaudus. Field-caught (from grass) M. montanus spent significantly more time in the grass habitat than either field-caught (from shrubs) (P<0.01) or grass-reared M. longicaudus (P<0.01) (Fig. 1).3.Early experience with grass was not a prerequisite for a choice, but experience with the grass habitat increased the grass affinity of M. montanus and lessened the variation in habitat occupancy (Fig. 1).4.M. longicaudus responded to early exposure to shrub and grass habitats by decreasing the individual variation in habitat occupancy. In contrast to M. montanus, the experience failed to increase the affinity for either natural habitat (Fig. 1).5.M. montanus males were larger in size and dominated in interspecific encounters. Strong aggression between the two species was not observed, since M. longicaudus exhibited a high propensity to withdraw from M. montanus. In contrast, M. montanus showed a low withdrawal propensity (Fig. 2).6.M. montanus probably is restricted to the grass habitat by its strong grass preference. M. longicaudus appears excluded from its preferred grass habitat by its propensity to withdraw from the dominant M. montanus.