Sex differences in parental care: Gametic investment, sexual selection, and social environment

Citations Over TimeTop 10% of 2015 papers

Abstract

Male and female parents often provide different type and amount of care to their offspring. Three major drivers have been proposed to explain parental sex roles: (1) differential gametic investment by males and females that precipitates into sex difference in care, (2) different intensity of sexual selection acting on males and females, and (3) biased social environment that facilitates the more common sex to provide more care. Here, we provide the most comprehensive assessment of these hypotheses using detailed parental care data from 792 bird species covering 126 families. We found no evidence for the gametic investment hypothesis: neither gamete sizes nor gamete production by males relative to females was related to sex difference in parental care. However, sexual selection correlated with parental sex roles, because the male share in care relative to female decreased with both extra-pair paternity and frequency of male polygamy. Parental sex roles were also related to social environment, because male parental care increased with male-biased adult sex ratios (ASRs). Taken together, our results are consistent with recent theories suggesting that gametic investment is not tied to parental sex roles, and highlight the importance of both sexual selection and ASR in influencing parental sex roles.

Related Papers

• → Time constraints and trade-offs among parental care behaviours: effects of brood size, sex and loss of mate(2004)94 cited
• → Post‐hatching parental care masks the effects of egg size on offspring fitness: a removal experiment on burying beetles(2012)62 cited
• → Parent–offspring conflict and its outcome under uni-and biparental care(2022)9 cited
• → Effects of parental care on offspring growth in the Korean wood-feeding cockroach, Cryptocercus kyebangensis(2003)23 cited
• → Parental feeding responses to experimental short-term partner removal in a species with male and female brood desertion(2019)12 cited