Early-life influences on the development of cooperation in wild mammals

合作性动物社会，其中成年人帮助抚养不属于自己的后代，一直是深入研究的焦点，因为它们可以帮助理解合作如何在面对自利的自然选择时演变。然而，这项研究还揭示了个体之间在对团队合作的贡献程度以及在抚养后代方面投入的努力方面存在巨大的无法解释的差异。对这种差异的一个合理的解释来自于对实验动物的研究，该研究表明，早期生活条件对成年人的健康和行为具有终生影响，这表明成年人之间在帮助努力方面的差异可能归因于他们早期生活发育经历和营养的差异。我们的研究将使用我们长期习惯的带状猫鼬研究种群来检验这一假设，带状猫鼬是一种高度合作的哺乳动物，生活在撒哈拉以南非洲地区约二十只的混合性别群体中。这个物种是这项任务的理想选择，因为个体群体成员之间对养育公共后代的贡献程度存在极大差异，而后代从成虫那里获得多少照顾和食物也存在极大差异。我们建立了一个关于 2200 多名个体的行为和生殖成功的详细数据库，这使我们能够测试这种早期生命护理差异的终生后果，并且我们可以进行喂养实验来测试母亲怀孕期间的营养是否对其后代产生终生影响。我们还将测量控制合作行为的潜在激素机制，并测试这些激素机制对早期生活经历和子宫内母亲营养的敏感性。该研究的成果将是更好地了解合作行为个体差异的原因，并提高对暴露于自然捕食者和病原体的哺乳动物群体发育的了解。

Cooperative animal societies, in which adults help to rear offspring that are not their own, have been the focus of intense research because they can help to understand how cooperation can evolve in the face of natural selection for self-interest. However, this research has also revealed great unexplained variation between individuals in how much they contribute to teamwork and how much effort they invest in rearing offspring. A plausible explanation for this variation comes from research on laboratory animals showing that early life conditions have lifelong impacts on adult health and behaviour, suggesting that differences in helping effort among adults could be attributable to variation in their early life developmental experiences and nutrition. Our research will test this hypothesis using our long-term habituated study population of banded mongooses, a highly cooperative mammal which lives in mixed-sex groups of around twenty individuals throughout sub-Saharan Africa. This species is ideal for the task because there is extreme variation among individual group members in how much they contribute to raising communal litters of offspring, and extreme variation among offspring in how much care and food they receive from adults. We have built up a detailed database on the behaviour and reproductive success of over 2200 individuals which enables us to test the lifetime consequences of this variation in early life care, and we can carry out feeding experiments to test whether maternal nutrition during pregnancy has lifelong impacts on their offspring. We will also measure the underlying hormonal mechanisms which control cooperative behaviour, and test how sensitive these hormonal mechanisms are to early life experiences and maternal nutrition in utero. The output of the research will be an improved understanding of the causes of individual variation in cooperative behaviour, and improved knowledge of mammalian development in populations exposed to natural predators and pathogens.