Szász Eszter, Garamszegi László Zsolt, Hegyi Gergely, Szöllősi Eszter, Markó Gábor, Török János, Rosivall Balázs
Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University, Pázmány Péter sétány 1/c, Budapest, 1117, Hungary,
Naturwissenschaften. 2014 Aug;101(8):653-60. doi: 10.1007/s00114-014-1204-0. Epub 2014 Jun 29.
Brood sex ratio is often affected by parental or environmental quality, presumably in an adaptive manner that is the sex that confers higher fitness benefits to the mother is overproduced. So far, studies on the role of parental quality have focused on parental morphology and attractiveness. However, another aspect, the partner's behavioral characteristics, may also be expected to play a role in brood sex ratio adjustment. To test this hypothesis, we investigated whether the proportion of sons in the brood is predicted by the level of territorial aggression displayed by the father, in the collared flycatcher (Ficedula albicollis). The proportion of sons in the brood was higher in early broods and increased with paternal tarsus length. When controlling for breeding date and body size, we found a higher proportion of sons in the brood of less aggressive fathers. Male nestlings are more sensitive to the rearing environment, and the behavior of courting males may often be used by females to assess their future parental activity. Therefore, adjusting brood sex ratio to the level of male aggression could be adaptive. Our results indicate that the behavior of the partner could indeed be a significant determinant in brood sex ratio adjustment, which should not be overlooked in future studies.
窝雏的性别比例通常会受到亲代质量或环境质量的影响，推测是以一种适应性的方式，即产生能为母亲带来更高繁殖适应性益处的性别。到目前为止，关于亲代质量作用的研究主要集中在亲代的形态和吸引力上。然而，另一个方面，配偶的行为特征，也可能在窝雏性别比例调整中发挥作用。为了验证这一假设，我们以白领姬鹟（Ficedula albicollis）为研究对象，调查了窝雏中雄性的比例是否由父亲表现出的领地攻击性水平所预测。早期窝雏中雄性的比例较高，且随着父本跗骨长度的增加而增加。在控制了繁殖日期和体型后，我们发现攻击性较弱的父亲所育窝雏中雄性的比例更高。雄性雏鸟对育雏环境更为敏感，雌性可能经常利用求偶雄性的行为来评估它们未来的亲代行为。因此，将窝雏性别比例调整到雄性攻击性水平可能具有适应性。我们的结果表明，配偶的行为确实可能是窝雏性别比例调整的一个重要决定因素，在未来的研究中不应被忽视。
