Parasites prevent summer breeding in white-footed mice, Peromyscus leucopus.
Parasites prevent summer breeding in white-footed mice, Peromyscus leucopus.
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寄生虫阻止白足小鼠（Peromyscus leucopus）夏季繁殖。
作者：
K. Vandegrift;T. Raffel;P. Hudson
食物和寄生虫可以独立地在动物种群的不稳定波动中发挥作用，然而，50多年前，大卫拉克提出，这两个因素应该协同作用。我们研究了这些因素对自由生活的白足鼠（Peromyscus leucopus）在夏季和秋季的生命率的作用。我们使用了一个重复的析因实验，其中鹿围栏增加了橡子的可用性和驱虫剂的应用减少胃肠道蠕虫。具体来说，我们想知道是否有任何一个因素或两者之间的相互作用导致了在这个物种中观察到的仲夏繁殖中断。我们没有发现栖息地质量对小鼠繁殖、生命率或人口统计学的影响;然而，驱虫剂治疗导致小鼠在中断期间继续以与以前相同的速度繁殖，并且它们还表现出身体状况、生长速度和存活率的增加。这些结果提供了证据表明，胃肠道蠕虫减少P. leucopus在宾夕法尼亚州中部的生殖输出，这些对生殖的影响可能在小型哺乳动物的不稳定动态中发挥作用。
Food and parasites can independently play a role in destabilizing population fluctuations of animals, and yet, more than 50 years ago, David Lack proposed that these two factors should act in concert. We examined the role of these factors on the vital rates of free-living white-footed mice (Peromyscus leucopus) over the summer and autumn months. We used a replicated factorial experiment in which deer exclosures doubled acorn availability and anthelmintic application reduced gastrointestinal helminths. Specifically, we wanted to know if either factor or an interaction between the two accounted for the midsummer breeding hiatus observed in this species. We found no influence of habitat quality on mouse breeding, vital rates, or demography; however, anthelmintic treatment resulted in mice continuing to reproduce during the hiatus at the same rate as previously, and they also exhibited increased body condition, growth rate, and survival. These results provide evidence that gastrointestinal helminths reduce P. leucopus reproductive output in central Pennsylvania, and these effects on reproduction could play a role in the unstable dynamics of small mammals.