Heeb P, Werner I, Mateman A C, Kölliker M, Brinkhof M W, Lessells C M, Richner H
Zoology Department, University of Bern, Centre for Behaviour and Evolution, Hinterkappelen-Bern, Switzerland.
Nature. 1999 Jul 1;400(6739):63-5. doi: 10.1038/21881.
Dispersal patterns of organisms are a fundamental aspect of their ecology, modifying the genetic and social structure of local populations. Parasites reduce the reproductive success and survival of hosts and thereby exert selection pressure on host life-history traits, possibly affecting host dispersal. Here we test experimentally whether infestation by hen fleas, Ceratophyllus gallinae, affects sex-related recruitment of great tit, Parus major, fledglings. Using sex-specific DNA markers, we show that flea infestation led to a higher proportion of male fledglings recruiting in the local population in one year. In infested broods, the proportion of male recruits increased with brood size over a three year period, whereas the proportion of male recruits from uninfested broods decreased with brood size. Natal dispersal distances of recruits from infested nests were shorter than those from uninfested nests. To our knowledge, this study provides the first evidence for parasite-mediated host natal dispersal and local recruitment in relation to sex. Current theory needs to consider parasites as potentially important factors shaping life-history traits associated with host dispersal.
生物的扩散模式是其生态学的一个基本方面，它会改变当地种群的遗传和社会结构。寄生虫会降低宿主的繁殖成功率和存活率，从而对宿主的生活史特征施加选择压力，可能影响宿主的扩散。在这里，我们通过实验测试鸡蚤（Ceratophyllus gallinae）的感染是否会影响大山雀（Parus major）雏鸟与性别相关的补充。使用性别特异性DNA标记，我们发现蚤类感染导致在某一年当地种群中招募的雄性雏鸟比例更高。在受感染的巢中，在三年时间里雄性补充个体的比例随巢大小增加，而未受感染巢中雄性补充个体的比例随巢大小下降。来自受感染巢穴的补充个体的出生扩散距离比未受感染巢穴的短。据我们所知，本研究首次提供了寄生虫介导的宿主出生扩散和与性别相关的当地补充的证据。当前理论需要将寄生虫视为塑造与宿主扩散相关的生活史特征的潜在重要因素。
