Data from: Effects of individual-based preferences for color-banded mates on sex allocation in zebra finches

Sex allocation theory predicts that females mated to attractive males produce more sons than females mated to unattractive males. However, previous tests of this hypothesis have obtained mixed results. We suggest that females differ in the traits they find attractive. To test this proposition we assessed female zebra finches’ preferences for males banded with red or green plastic leg bands, and then tested the sex allocation pattern of females paired with preferred and non-preferred males. Although most females preferred red-banded males, 34% of females consistently preferred green-banded males. The sex ratio at laying and hatching was not influenced by paternal preferred status. However, the fledging sex ratios differed between females paired with preferred and non-preferred males due to sex-biased chick mortality; sons of females paired with preferred males were born heavier and were more likely to survive than were daughters. Our results indicate that female zebra finches show individual variation in their preferences for color banded males, although females do not seem to adjust the offspring sex ratio in response to their mate’s band color. However, the differential post-hatch mortality suggests females may differentially allocate resources into male and female eggs according to their individual mate preferences.性分配理论（Sex allocation theory）预测，与具有吸引力的雄性交配的雌性，其后代雄性比例将高于与无吸引力雄性交配的雌性。然而，此前针对这一假说的验证实验得到了不一致的结果。为此我们提出，雌性个体对雄性吸引力的评判标准存在个体差异。为验证这一命题，我们首先评估了雌性斑胸草雀（zebra finches）对佩戴红色或绿色塑料腿环的雄性的偏好性，随后分别检测了与偏好雄性、非偏好雄性配对的雌性的性分配模式。尽管多数雌性偏好佩戴红色腿环的雄性，但仍有34%的雌性始终青睐绿色腿环的雄性。产卵及孵化阶段的后代性比并未受父本偏好性的影响。但由于存在性别偏向性的雏鸟死亡率，与偏好雄性配对的雌性和与非偏好雄性配对的雌性，其离巢期后代性比存在显著差异：与偏好雄性配对的雌性所产雄性幼鸟出生时体重更高，且存活率高于雌性幼鸟。本研究结果表明，雌性斑胸草雀对佩戴彩色腿环的雄性的偏好存在个体差异，尽管雌性似乎并未根据配偶的腿环颜色调整后代性比。但孵化后存在的差异化死亡率表明，雌性或可根据自身对配偶的个体偏好，差异化地向雄性和雌性卵中分配资源。