Cook W M, Timm R M, Hyman D E
Department of Ecology and Evolutionary Biology & Natural History Museum, Dyche Hall, University of Kansas, Lawrence, KS 66045, USA.
Rev Biol Trop. 2001 Sep-Dec;49(3-4):1177-81.
We investigated the swimming abilities of three Costa Rican dry forest rodents (Coues' rice rat. Oryzomys couesi, hispid cotton rat, Sigmodon hispidus, and spiny pocket mouse, Liomys salvini) associated with a large marsh, Laguna Palo Verde, using 90 s swim trials in a plastic container. Swimming ability was evaluated by observing the use of limbs and tail in the water, inclination to the surface, and diving and floating behavior. Rice rats could float, swim and dive, suggesting that they can exploit surface and underwater resources. Cotton rats swam at the water's surface, but were less skilled swimmers than rice rats. Spiny pocket mice tired quickly and had difficulty staying at the water's surface. Results suggest that differential swimming ability is related to the distribution of the three sympatric species within the marsh and adjacent forest habitats.
我们利用在塑料容器中进行的90秒游泳试验，研究了与一个大型沼泽——拉古纳·帕洛·弗德相关的三种哥斯达黎加干旱森林啮齿动物（库氏稻鼠，Oryzomys couesi；刚毛棉鼠，Sigmodon hispidus；多刺囊鼠，Liomys salvini）的游泳能力。通过观察在水中四肢和尾巴的使用情况、身体与水面的倾斜度以及潜水和漂浮行为来评估游泳能力。稻鼠能够漂浮、游泳和潜水，这表明它们可以利用水面和水下资源。棉鼠在水面游泳，但游泳技能不如稻鼠。多刺囊鼠很快就疲惫不堪，并且很难停留在水面上。结果表明，不同的游泳能力与这三种同域分布的物种在沼泽及相邻森林栖息地中的分布有关。
