Male care and life history traits in mammals.

Hannah E R West,Isabella Capellini

doi:10.1038/ncomms11854

Abstract

Male care has energetic and opportunity costs, and is more likely to evolve when males gain greater certainty of paternity or when future mating opportunities are scarce. However, little is known about the substantial benefits that males may provide to females and offspring. Using phylogenetic comparative methods and a sample of over 500 mammalian species, we show that mammals in which males carry the offspring have shorter lactation periods, which leads to more frequent breeding events. Provisioning the female is associated with larger litters and shorter lactation. Offspring of species with male care have similar weaning mass to those without despite being supported by a shorter lactation period, implying that they grow faster. We propose that males provide an energetic contribution during the most expensive time of female reproduction, lactation, and that different male care behaviours increase female fecundity, which in turn helps males offset the costs of caring.

Highlights

Male care has energetic and opportunity costs, and is more likely to evolve when males gain greater certainty of paternity or when future mating opportunities are scarce
Our analysis across 529 mammals with and without male care (Fig. 1) shows that lactation time is significantly shorter in species with male care (Fig. 2a), while accounting for allometry and gestation time, but is unrelated to all other predictors
The amount of variance explained by the reduced model with male care increases by 2% relative to a model without it (LR1 1⁄4 6.1, P 1⁄4 0.013)

Summary

Introduction

Male care has energetic and opportunity costs, and is more likely to evolve when males gain greater certainty of paternity or when future mating opportunities are scarce. By caring for the offspring post-weaning, males may allow females to invest more time foraging, regain body condition more quickly and mate sooner, regardless of the duration of lactation[27] Discriminating between these scenarios and identifying the relevant male care behaviour at a given stage of reproduction is fundamental because it helps to pinpoint the mechanism that underlies the evolutionary associations between male care and life history traits, and the possible evolutionary feedback between them. Regardless of whether a higher frequency of breeding is achieved through male care post-weaning or by enabling females to wean the offspring sooner, higher female reproductive rates benefit the male only if he mates with the same female over more than one breeding event This appears to be the case in mammals as recent comparative studies conclude that the evolution of social monogamy precedes the evolution of male care and is evolutionarily associated with it[19,20]. Whether longer-lived species are more likely to exhibit male care is, unknown

Methods

Results

Conclusion