MATING PATTERNS, SEXUAL SELECTION AND PARENTAL CARE: AN INTEGRATIVE APPROACH

Abstract

Mating patterns, sexual selection and parental care are central topics in behavioural ecology, but they are often analysed in isolation from each other. We propose a new conceptual framework to investigate these topics in relation to each other. We argue that it is beneficial to study both mating behaviour and parental care of all types of individual in a population, because the behaviours of different individuals are interrelated in many ways. In particular, we propose a framework in which the parental care adopted is the best response to the mating behaviour and the mating behaviour adopted is the best response to the parental behaviour. The backbone of the proposed framework is the feedback relationship between mating strategies (e.g. accepting or rejecting a mate), mating opportunities (related to the number and quality of animals searching for a mate) and parental care strategies (e.g. caring for the offspring or deserting them). For instance, mating opportunities should influence both the mating and parental strategies. The mating and parental strategies, in turn, have an effect on mating opportunities. We emphasise the conceptual significance of these feedback loops as well as referring to empirical studies which have demonstrated some of these feedbacks. The strength of these feedbacks probably vary between species and may be negligible in some systems. Unlike most previous approaches to mating behaviour and parental care, we do not assume that mating systems, parental investments by males and females, operational sex ratio, reproductive rates, or the intensity of sexual selection are fixed in a population. Rather, these characteristics emerge when one specifies the behavioural options of males and females, and their consequences. Mating and parental decisions can have consequences beyond the immediate breeding attempt and the proposed framework allows us to investigate such decisions from a life-history perspective. Mating and caring decisions involve various interactions among members of a population (e.g. conflicts between prospective mates, and between male and female parents), thus studying mating and caring behaviour benefits from the use of game theory. Since the state of animals (e.g. whether they are mated or not, their age, energy reserves or the number of their offspring) and the time in the breeding season commonly influence the payoffs from different behavioural options, we advocate the use of state-dependent dynamic game theory as a suitable approach for the analysis of such decisions. Finally, we call for a new generation of theoretical models and empirical studies to understand the diverse mating and parental behaviour of animals which have fascinated evolutionary biologists from Darwin onwards.