Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, , 1790 AB Den Burg, The Netherlands, Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, , PO Box 11103, 9700 CC Groningen, The Netherlands.
Proc Biol Sci. 2014 Mar 26;281(1783):20133135. doi: 10.1098/rspb.2013.3135. Print 2014 May 22.
The evolutionary function and maintenance of variation in animal personality is still under debate. Variation in the size of metabolic organs has recently been suggested to cause and maintain variation in personality. Here, we examine two main underlying notions: (i) that organ sizes vary consistently between individuals and cause consistent behavioural patterns, and (ii) that a more exploratory personality is associated with reduced survival. Exploratory behaviour of captive red knots (Calidris canutus, a migrant shorebird) was negatively rather than positively correlated with digestive organ (gizzard) mass, as well as with body mass. In an experiment, we reciprocally reduced and increased individual gizzard masses and found that exploration scores were unaffected. Whether or not these birds were resighted locally over the 19 months after release was negatively correlated with their exploration scores. Moreover, a long-term mark-recapture effort on free-living red knots with known gizzard masses at capture confirmed that local resighting probability (an inverse measure of exploratory behaviour) was correlated with gizzard mass without detrimental effects on survival. We conclude that personality drives physiological adjustments, rather than the other way around, and suggest that physiological adjustments mitigate the survival costs of exploratory behaviour. Our results show that we need to reconsider hypotheses explaining personality variation based on organ sizes and differential survival.
动物个性的进化功能和维持仍然存在争议。最近有人提出，代谢器官的大小变化会导致并维持个性的变化。在这里，我们检验了两个主要的基本概念：（i）器官大小在个体之间是否存在一致性变化，并导致一致的行为模式；（ii）更具探索性的个性是否与降低生存能力有关。圈养红腹滨鹬（Calidris canutus，一种迁徙滨鸟）的探索行为与消化器官（砂囊）质量以及体重呈负相关，而不是正相关。在一项实验中，我们对个体砂囊质量进行了相互增减的操作，发现探索得分没有受到影响。在释放后的 19 个月内，这些鸟类是否在当地重新被发现与它们的探索得分呈负相关。此外，对自由生活的红腹滨鹬进行的长期标记重捕研究证实，在捕获时已知砂囊质量的红腹滨鹬，当地再发现的概率（探索行为的逆指标）与砂囊质量相关，而不会对生存产生不利影响。我们的结论是，个性驱动生理调整，而不是相反，并表明生理调整减轻了探索行为的生存代价。我们的研究结果表明，我们需要重新考虑基于器官大小和差异生存解释个性变异的假说。
