PDF(Pubmed)
Abstract：
Phenotypic differences often stem from genetic/maternal differences and/or early-life adaptations to local environmental conditions. In colonial animals, little is known on how variation in the social environment is embedded into individual phenotypes, nor what the consequences are on individual fitness. We conducted an experimental cross-fostering study on king penguins (Aptenodytes patagonicus), exchanging eggs among 134 pairs breeding in high-density (67 pairs) or low-density (67 pairs) areas of the same breeding colony. We investigated differences in parent and chick phenotypes and survival in relation to the density of their origin and foster environment. Adults breeding in colony areas of high density exhibited decreased resting behaviour and increased aggression and vigilance, increased hypometabolism during incubation fasts, and more moderate corticosterone responses shaped by exposure to chronic stressors (e.g. constant aggression by neighbours). Chick phenotypes were more influenced by the environment in which they were raised than their genetic/maternal origin. Chicks raised in high-density colonial environments showed enhanced weight gain and survival rates regardless of the density of their genetic parents\' breeding areas. Our study experimentally shows advantages to breeding in colonial areas of higher breeder densities in king penguins, and highlights the importance of social settings in shaping phenotype expression in colonial seabirds.
摘要：
表型差异通常源于遗传/母体差异和/或对当地环境条件的早期适应。在殖民地动物中，关于社会环境中的变异是如何嵌入到个体表型中的，人们知之甚少，也不影响个人健康。我们对国王企鹅（Aptenodytespatagonicus）进行了实验性交叉培养研究，在同一繁殖群体的高密度（67对）或低密度（67对）区域中繁殖的134对之间交换卵。我们调查了亲本和雏鸡表型和存活率与其起源密度和寄养环境有关的差异。在高密度殖民地繁殖的成年人表现出减少的休息行为，增加的攻击性和警惕性，在孵育禁食期间增加的低代谢，和更温和的皮质酮反应形成暴露于慢性应激源（例如邻居的持续攻击）。与遗传/母本起源相比，小鸡表型受生长环境的影响更大。在高密度殖民地环境中饲养的小鸡无论其遗传父母的繁殖区域的密度如何，都显示出体重增加和存活率的提高。我们的研究通过实验表明，在国王企鹅的繁殖密度较高的殖民地地区繁殖具有优势，并强调了社会环境在塑造殖民地海鸟表型表达中的重要性。
