Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064, USA.
Curr Biol. 2011 Mar 22;21(6):515-9. doi: 10.1016/j.cub.2011.02.023.
The reliability of information that animals use to make decisions has fitness consequences. Accordingly, selection should favor the evolution of strategies that enhance the reliability of information used in learning and decision making. For example, hosts of avian brood parasites should be selected to increase the reliability of the information they use to learn to recognize their own eggs and chicks. The American coot (Fulica americana), a conspecific brood parasite, uses cues learned from the first-hatched chicks of each brood to recognize and reject parasitic chicks. However, if parasitic eggs are among the first to hatch, recognition cues are confounded and parents then fail to distinguish parasitic chicks from their own chicks. Therefore, hosts could ensure correct chick recognition by delaying parasitic eggs from hatching until after the first host eggs. Here we demonstrate that discriminatory incubation, whereby coots specifically delay the hatching of parasitic eggs, improves the reliability of parasitic chick recognition. In effect, coots gain fitness benefits by enhancing the reliability of information they later use for learning. Our study shows that a positive interaction between two host adaptations in coots--egg recognition and chick recognition--increases the overall effectiveness of host defense.
动物在决策中所使用的信息的可靠性具有适应意义。因此，选择应该有利于进化出增强学习和决策中使用的信息可靠性的策略。例如，鸟类巢寄生者的宿主应该被选择来增加他们用来识别自己的蛋和雏鸟的信息的可靠性。美洲骨顶鸡（Fulica americana）是一种同域的巢寄生者，它利用从每个巢穴中第一只孵化的雏鸟中学到的线索来识别和拒绝寄生雏鸟。然而，如果寄生卵是最早孵化的卵之一，那么识别线索就会混淆，父母就无法区分寄生雏鸟和自己的雏鸟。因此，宿主可以通过延迟寄生卵孵化，直到第一批宿主卵孵化之后，来确保正确的雏鸟识别。在这里，我们证明了区分性孵化，即骨顶鸡专门延迟寄生卵的孵化，提高了寄生雏鸟识别的可靠性。实际上，骨顶鸡通过增强它们以后用于学习的信息的可靠性而获得了适应度上的好处。我们的研究表明，在骨顶鸡中，两种宿主适应——卵识别和雏鸟识别——之间的积极相互作用，提高了宿主防御的整体效果。
