期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2016
卷号：113
期号：48
页码：13803-13808
DOI：10.1073/pnas.1606378113
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceShould a chick beg for food even if it isnt struggling to grow? Does it have anything to lose? The answer could be "yes" if it risks losing indirect fitness through the starvation of siblings. Evolutionary theory suggests that offspring may be more likely to exaggerate signals of need when they compete with less-related nestmates or a greater number of nestmates. We found clear support for this hypothesis in an analysis across 60 bird species. Offspring begging was less reliable in species where parents produce larger broods and more broods and where parental divorce or death reduces between-brood relatedness. This result helps explain why chicks of some species are more honest than others and tests general predictions of signaling theory. Offspring survival can often depend on successful communication with parents about their state of need. Theory suggests that offspring will be less likely to honestly signal their need when they experience greater competition from either a greater number of nestmates or less-related nestmates. We found support for this hypothesis with a comparative analysis, examining data from across 60 species of birds. We found that offspring are less honest about their level of need when (i) they face competition from current siblings; (ii) their parents are likely to breed again, and so they are in competition with future siblings; and (iii) parental divorce or death means that they are likely to be less related to future siblings. More generally, these patterns highlight the sensitivity of communication systems to conflict between signaler and receiver while also suggesting that when there is little conflict, natural selection favors the honest.
