Am Nat. 2020 Aug;196(2):257-269. doi: 10.1086/709106. Epub 2020 Jun 10.
Kin selection and reciprocation of biological services are distinct theories invoked to explain the origin and evolutionary maintenance of altruistic and cooperative behaviors. Although these behaviors are not considered to be mutually exclusive, the cost-benefit balance of behaving altruistically or cooperating reciprocally and the conditions promoting a switch between such different strategies have rarely been tested. Here, we examine the association between allofeeding, allopreening, and vocal solicitations in wild barn owl () broods under different food abundance conditions: natural food provisioning and after an experimental food supplementation. Allofeeding was performed mainly by elder nestlings (hatching is asynchronous) in prime condition, especially when the cost of forgoing a prey was small (when parents allocated more prey to the food donor and after food supplementation). Nestlings preferentially shared food with the siblings that emitted very intense calls, thus potentially increasing indirect fitness benefits, or with the siblings that provided extensive allopreening to the donor, thus possibly promoting direct benefits from reciprocation. Finally, allopreening was mainly directed toward older siblings, perhaps to maximize the probability of being fed in return. Helping behavior among relatives can therefore be driven by both kin selection and direct cooperation, although it is dependent on the contingent environmental conditions.
亲族选择和生物服务的互惠是用来解释利他和合作行为的起源和进化维持的两个不同理论。尽管这些行为不被认为是相互排斥的，但表现出利他或互惠合作的成本效益平衡，以及促进这些不同策略之间转换的条件，很少被测试。在这里，我们研究了在不同食物丰度条件下野生仓鸮（）雏鸟中的育雏亲代喂食、育雏梳理和发声请求之间的关联：自然食物供应和实验性食物补充后。在最佳条件下，年长的雏鸟（孵化是异步的）主要进行育雏亲代喂食，特别是当放弃猎物的成本较小时（当父母将更多的猎物分配给食物捐赠者并在食物补充后）。雏鸟更喜欢与发出非常强烈叫声的兄弟姐妹分享食物，从而潜在地增加间接适应度收益，或者与为捐赠者提供广泛育雏梳理的兄弟姐妹分享食物，从而可能从互惠中获得直接收益。最后，育雏梳理主要针对年长的兄弟姐妹，也许是为了最大限度地提高回报喂养的可能性。因此，亲族间的帮助行为可以同时受到亲族选择和直接合作的驱动，尽管这取决于偶然的环境条件。
