Parents of the Azure‑winged Magpie exhibit sex‑specific allocation of food to offspring
Parents of the Azure‑winged Magpie exhibit sex‑specific allocation of food to offspring
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天蓝色喜鹊的父母表现出性别对后代食物的特定分配
DOI：
10.1007/s10336-017-1502-3
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发表时间：
2017
影响因子：
1.3
通讯作者：
Du Bo
中科院分区：
文献类型：
--
作者：
Da Xin-Wei;Xian Li-Li;Luo Juan-Juan;Du Bo
性别分配理论的模型表明，当儿子和女儿的生殖价值与父母不同时，父母会过度生产更高价值的后代，以最大限度地提高他们的生殖成功率。对这些模型的实证检验仍无定论。我们调查了蓝翅喜鹊（Cyanopica cyana），一种合作繁殖的鸟类，父母是否控制后代的性别比例，以及他们是否表现出性别特异性的食物分配之间的雏鸟。结果表明，在合作组和双亲巢中，孵化和羽化时的子代性比均未偏离当量比。没有任何因素与孵化时的后代性别比显著相关，表明父母没有控制他们的后代性别比。但是，父母采取了两种产后策略来控制雏鸟的生长模式。首先，他们给儿子的食物比给女儿的多，以确保儿子的生存。第二，根据子代性别比例调整每次投喂的投喂率和食物分配时间，积极响应雏鸟的乞讨行为，提高子代的存活率。我们的研究结果表明，父母采取的出生后策略，在特定性别的食物分配给后代方面，可能比产前策略发挥更大的作用，即，控制后代性别比例，提高繁殖成功率。
Models of sex allocation theory suggest that when sons and daughters have different reproductive values to their parents, parents overproduce offspring of higher value to maximize their reproductive success. Empirical testing of these models remains inconclusive. We investigated whether parents of the Azure-winged Magpie (Cyanopica cyana), a cooperatively breeding bird, controlled offspring sex ratios and whether they exhibited sex-specific food allocation among nestlings. Our results showed that offspring sex ratios at hatching and fledging did not deviate from equivalent ratio in both cooperative groups and bi-parental nests. No factors were significantly correlated with offspring sex ratios at hatching, indicating that parents did not control their offspring sex ratios. However, parents adopted two postnatal strategies to control the growth pattern of nestlings. First, they delivered more food to their sons than their daughters to ensure the survivorship of their sons. Second, they adjusted the feeding rates and food allocation time per feeding bout according to the offspring sex ratios and positively responded to the begging behavior of nestlings to increase the survivorship of the daughters. Our findings suggest that the postnatal strategies adopted by the parents, in terms of sex-specific allocation of food to offspring, may play a greater role than the prenatal strategies, i.e., the control of offspring sex ratios, in the enhancement of reproductive success.