Social conflict and costs of cooperation in meerkats are reflected in measures of stress hormones
Social conflict and costs of cooperation in meerkats are reflected in measures of stress hormones
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DOI：
10.1093/beheco/arx077
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发表时间：
2017-07-01
影响因子：
2.4
通讯作者：
Clutton-Brock, Tim H.
中科院分区：
文献类型：
--
作者：
Dantzer, Ben;Bennett, Nigel C.;Clutton-Brock, Tim H.
糖皮质激素应激激素(如皮质醇)的测量经常被用来描述下属和支配者之间的冲突。在合作繁育者中，下属很少在其出生的群体中繁殖并帮助抚养后代，下属糖皮质激素水平的增加可能是由于下属之间的冲突以及帮助行为的能量成本和食物供应的波动可能加剧这些影响。在对Kalahari meerkats(Suricata Suricatta)进行的一项为期6年的研究中，我们调查了社会、环境和个人特征如何影响下属的血浆皮质醇水平。从属雌性经常成为优势雌性攻击的目标，当她们组中的优势雌性怀孕时，皮质醇水平较高，而从属雄性的皮质醇水平不受优势雌性生殖状态的影响。如果属于1)群体中的两个主要繁殖者都不是他们的父母，2)包含较高比例的从属雌性，或3)非常大或非常小的群体，特别是在天气寒冷和干燥的时候，两性的下级都有更高的皮质醇水平。在包含幼崽的小组中，下属的皮质醇水平更高。最后，如果男性和女性的下属的皮质醇水平都比他们的年龄轻，或者在采样前一晚体重几乎没有下降，那么他们的皮质醇水平就会更高。我们的结果表明，社会冲突和合作行为都能提高下属的糖皮质激素水平，而且这两种影响都可以被天气和食物供应的变化所改变。
Measures of glucocorticoid stress hormones (e.g. cortisol) have often been used to characterize conflict between subordinates and dominants. In cooperative breeders where subordinates seldom breed in their natal group and assist in offspring rearing, increases in subordinate glucocorticoid levels may be caused by conflict among subordinates as well as by the energetic costs of helping behavior and fluctuations in food availability may exacerbate these effects. During a 6-year study of Kalahari meerkats (Suricata suricatta), we investigated how social, environmental, and individual characteristics influenced subordinate plasma cortisol levels. Subordinate females, who are often the target of aggression from dominant females, had higher cortisol levels when the dominant female in their group was pregnant while the cortisol levels of subordinate males were unaffected by the reproductive state of dominant females. Subordinates of both sexes had higher cortisol levels if they belonged to groups 1) where neither of the dominant breeders in the group were their parents, 2) that contained a high proportion of subordinate females, or 3) that were either very large or very small, especially when the weather was cold and dry. Subordinates in groups containing young pups had higher cortisol levels. Finally, cortisol levels were higher in subordinates of both sexes if they were lighter for their age or had lost little body mass the night prior to sampling. Our results show that both social conflict and cooperative behavior can elevate glucocorticoid levels in subordinates and that both effects can be modified by variation in weather and food availability.