Group-level competition influences urinary steroid hormones among wild red-tailed monkeys, indicating energetic costs
Group-level competition influences urinary steroid hormones among wild red-tailed monkeys, indicating energetic costs
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DOI：
10.1002/ajp.22757
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发表时间：
2018-05-01
影响因子：
2.4
通讯作者：
Brown, Michelle
中科院分区：
文献类型：
--
作者：
Jaeggi, Adrian V.;Trumble, Benjamin C.;Brown, Michelle
各种理论都强调群体间竞争应该影响群体内的合作和社会关系，特别是当群体间竞争的成本超过群体内竞争的成本时。这种群体间竞争的代价可以通过生理状态的变化来量化，比如类固醇激素皮质醇(C)和睾丸激素(T)的变化，这两种激素在能量压力期间分别升高或降低。在乌干达Kibale国家公园的Ngogo站，我们测试了野生红尾猴（Cercopithecus ascanius）在群间相遇（IGEs）后尿液C和T的变化。红尾猴是一种经常经历群间喂养竞争的物种。我们分析了来自4个社会群体的23个个体的108份尿液样本，其中36份是在IGEs之后收集的。控制各种混杂因素的贝叶斯多水平模型显示，相对于基线，IGEs增加了C，降低了T，这与IGEs的能量成本一致。在IGEs后早期收集的样本中，C的变化更为明显，表明预期的增加，而T的变化在后期的样本中更强，表明持续的能量权衡。激素反应不受IGE结果的影响。这种群体间竞争的代价，加上零售业和其他领域群体内竞争的证据很少，为强调群体间竞争对群体内合作影响的理论建立了一个有趣的测试案例。
Various theories emphasize that intergroup competition should affect intragroup cooperation and social relationships, especially if the cost of intergroup competition outweighs that of intragroup competition. This cost of intergroup competition may be quantified by changes in physiological status, such as in the steroid hormones cortisol (C) and testosterone (T), which rise or are depressed during periods of energetic stress, respectively. Here we tested for changes in urinary C and T after intergroup encounters (IGEs) among wild red-tailed monkeys (Cercopithecus ascanius), a species that experiences frequent intergroup feeding competition, at the Ngogo station in Kibale National Park, Uganda. We assayed 108 urine samples, of which 36 were collected after IGEs, from 23 individuals in four social groups. Bayesian multilevel models controlling for various confounds revealed that IGEs increased C and decreased T relative to baseline, consistent with an energetic cost to IGEs. The C change was more apparent in samples collected early after IGEs, suggesting an anticipatory increase, whereas the T change was stronger in later samples, suggesting sustained energetic trade-offs. Hormone responses were not affected by the IGE outcome. This cost to intergroup competition, together with little evidence for intragroup competition in redtails and other guenons, establishes an interesting test case for theories emphasizing the effect of intergroup competition on intragroup cooperation.