Abstract: Social organization and mating systems of mammals are known primarily for large, easily observed, long-lived species. There is relatively little such information for small, secretive, short-lived species because of difficulty in observing direct interacaions between individuals in the wild. Data relating to social organization and mating systems normally must be obtained by indirect means,such as by radiotelemetry or live-trapping.

Key words: Prairie vole, Microtus ochrogaster, Meadow vole, Microtus pennsylvanicus, Social organization, Mating systems

摘要： 田鼠亚科的两种啮齿动物黄腹田鼠(prairie vole,Microtus ochrogaster)和草甸田鼠(meadow vole,M.pennsylvanicus)是社会组织完全不同的两个种。黄腹田鼠原始栖息地在北美北部中央大片毗连的草原上,生境较稳定。该种易于接触,其交配为一夫一妻制,并成对结合。雌雄鼠共居在同一巢穴里,雌鼠只与配对雄鼠交配,雄鼠回避非配对的外来雌鼠,并分担巢穴的营造和维修,同时也照管幼仔,包括饲养、聚集和挽救。幼体断乳后,多数仍留在巢穴里,并协助照管下一窝幼仔,不参加繁殖,只有那些从家族群中扩散出去,并与无亲缘关系的雄鼠交配的雌性青年鼠才能繁殖后代。这种交配制度的作用是扩散种群,子代为寻求婚配而从家族群中离去,从而避免局部种群密度增高,以及由此造成的食物短缺。由于繁殖对是由非亲缘关系的个体结合而成,避免了近亲繁殖及由此带来的遗传性有害影响。

关键词: 黄腹田鼠, 草甸田鼠, 社会组织, 交配系统