Communal roosting shows dynamics predicted by direct and indirect nepotism in chestnut-crowned babblers
Communal roosting shows dynamics predicted by direct and indirect nepotism in chestnut-crowned babblers
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栗冠鹛的公共栖息表现出直接和间接裙带关系所预测的动态
DOI：
10.1007/s00265-020-02958-2
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发表时间：
2021
影响因子：
2.3
通讯作者：
Russell Andrew F.
中科院分区：
文献类型：
--
作者：
Nomano Fumiaki Y.;Savage James L.;Rollins Lee A.;Griffith Simon C.;Russell Andrew F.
家庭生活是一个垫脚石，更高层次的社会结构，包括合作繁殖的群体，但理解为什么后代仍然与父母推迟分散仍然是一个挑战。家庭生活的一个很少被研究的方面是公共的拥挤栖息，其中个体聚集在一起过夜，以获得温度调节和/或抗捕食者的好处。在这里，我们使用的PIT标签检测系统，调查潜在的直接和间接裙带关系在栖息拥挤的合作繁殖栗冠穗鹛（Pomatostomus ruficeps）生活在大家庭与女性移民。该物种习惯于在单室圆顶巢中共同栖息;在本研究中，平均8.5（± 4.4 SD）只个体需要约6分钟即可进入一起栖息的栖息巢。我们发现，个人在栖息地定居的顺序与他们的出口顺序呈负相关，和那些定居晚更有可能被检测到在夜间在巢入口，这表明定居顺序影响个人的栖息位置。少年进入栖息在中等位置，他们的条目与增加活动水平的照顾者，这表明直接裙带关系的援助。此外，移民女性更经常定居在栖息地比其他人晚，这表明间接裙带关系，通过排斥移民从更中央的栖息位置。这种排除没有明显的年龄或性别混淆。由于那些定居后，预计将减少体温调节的好处和增加捕食的风险，我们的研究结果表明，直接和间接的裙带关系的好处，在公共栖息可能会提供部分解释家庭生活通过延迟分散在这个species.Significance statementNepotism-优惠待遇对亲属或对非亲属-可能会导致个人受益于留在他们的纳塔尔组，而不是分散，因此增加了家庭生活的倾向，并随后进化为合作繁殖。一个可能的途径，通过延迟分散可能获得裙带关系的好处是在公共栖息拥挤，个人栖息更集中可能会收到更大的温度调节和/或捕食者回避的好处。据我们所知，研究还没有发现纳塔尔的个人在社区栖息期间获得照顾以外的优势。我们发现，移民女性定居在公共栖息地晚于营养独立的纳塔尔女性，并可能占据周边位置的合作繁殖栗冠穗鹛（Pomatostomus ruficeps）使用远程PIT标签系统的栖息地。这种明显的移民劣势可能在促进延迟扩散方面具有重要意义。
AbstractFamily living is a stepping stone to higher-order social structures including cooperatively breeding groups, but understanding why offspring remain with parents by delaying dispersal remains a challenge. One rarely studied aspect of family living is communal huddle roosting, where individuals group together overnight for thermoregulatory and/or anti-predator benefits. Here, we use a PIT-tag detection system to investigate the potential for direct and indirect nepotism in roosting huddles of cooperatively breeding chestnut-crowned babblers (Pomatostomus ruficeps) living in extended families with female immigrants. This species habitually roosts communally in single-chambered domed nests; an average of 8.5 (± 4.4 SD) individuals taking ~6 min to enter roost nests roosted together in this study. We found that the order in which individuals settled in the roost was negatively associated with their exit order, and those settling late were more likely to be detected at the nest entrance during the night, suggesting that settlement order influences individual roosting positions. Juveniles entered the roost in mid-rank positions, and their entries were associated with increased activity levels of carers, suggesting direct nepotistic assistance. In addition, immigrant females more often settled in the roosts later than others, suggesting indirect nepotism through exclusion of immigrants from more central roosting positions. This exclusion was not obviously confounded by age or sex. As those settling later are expected to experience reduced thermoregulatory benefits and increased predation risk, our results suggest that direct and indirect nepotistic benefits during communal roosting might offer part of the explanation for family living through delayed dispersal in this species.Significance statementNepotism—preferential treatment towards kin or against non-kin—may lead to individuals benefiting from staying in their natal group rather than dispersing, and so increasing the propensity for family living and the subsequent evolution of cooperative breeding. One possible route through which delayed dispersers might gain nepotistic benefits is in communal roosting huddles, as individuals roosting more centrally are likely to receive greater thermoregulatory and/or predator avoidance benefits. To our knowledge, studies have yet to discover an advantage of natal individuals beyond care received as young during communal roosting. We show that immigrant females settle in the communal roosts later than nutritionally independent natal females and may occupy peripheral positions in roosts of the cooperatively breeding chestnut-crowned babbler (Pomatostomus ruficeps) using a remote PIT-tag system. This apparent immigrant disadvantage might be significant in promoting delayed dispersal.