Hinde Camilla A, Buchanan Katherine L, Kilner Rebecca M
Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
Proc Biol Sci. 2009 Aug 7;276(1668):2787-94. doi: 10.1098/rspb.2009.0375. Epub 2009 May 6.
The solicitation behaviours performed by dependent young are under selection from the environment created by their parents, as well as wider ecological conditions. Here we show how mechanisms acting before hatching enable canary offspring to adapt their begging behaviour to a variable post-hatching world. Cross-fostering experiments revealed that canary nestling begging intensity is positively correlated with the provisioning level of their own parents (to foster chicks). When we experimentally increased food quality before and during egg laying, mothers showed higher faecal androgen levels and so did their nestlings, even when they were cross-fostered before hatching to be reared by foster mothers that had been exposed to a standard regime of food quality. Higher parental androgen levels were correlated with greater levels of post-hatching parental provisioning and (we have previously shown) increased faecal androgens in chicks were associated with greater begging intensity. We conclude that androgens mediate environmentally induced plasticity in the expression of both parental and offspring traits, which remain correlated as a result of prenatal effects, probably acting within the egg. Offspring can thus adapt their begging intensity to variable family and ecological environments.
依赖亲鸟的幼鸟所表现出的乞食行为，受到其父母所营造的环境以及更广泛生态条件的选择作用影响。在此，我们展示了孵化前起作用的机制如何使金丝雀幼雏能够让其乞食行为适应孵化后多变的世界。交叉寄养实验表明，金丝雀雏鸟的乞食强度与其自身父母（对于寄养雏鸟而言）的育雏水平呈正相关。当我们在产卵前及产卵期间通过实验提高食物质量时，母鸟粪便中的雄激素水平升高，其雏鸟也是如此，即便这些雏鸟在孵化前被交叉寄养，由处于标准食物质量条件下的养母抚养。较高的亲代雄激素水平与孵化后更高的亲代育雏水平相关，并且（我们之前已经表明）雏鸟粪便中雄激素增加与更强的乞食强度相关。我们得出结论，雄激素介导了亲代和子代性状表达中由环境诱导的可塑性，由于产前效应，这些性状仍保持相关性，这种效应可能在卵内起作用。因此，子代能够使其乞食强度适应多变的家庭和生态环境。
