Natural variation in biological traits provides the ‘raw material’ for the action of selection and thus allows for evolution and speciation. In general, phenotypic variation is owing to genetic differences between individuals and to flexible/conditional responses of individuals to changing environmental factors, and to the interaction between these two factors. A longstanding challenge in Evolutionary Ecology has been to understand not only how variation in traits that are under selection, including behaviour, arises in populations but also how it is maintained. Despite recent advances, much work remains to elucidate the mechanisms generating and maintaining such variation, and the consequences of the latter for the processes of selection and evolution.The long-term, general objective of my research programme is to contribute to a more comprehensive understanding of how natural and sexual selection are mediated by social factors and how they interact to shape behaviour and maintain variation in behaviour within and between populations. Towards meeting this challenge, recent and current research in my laboratory aim to ascertain the extent to which social context (social factors) influences the behavioural decisions of individuals that live in social groups, with a particular focus on mating, risk-taking, antipredator, and social association behaviour. Group living in animals, including fishes, is very common in nature. Natural variation in the size and composition of social groups generates diverse social contexts (“social templates”) within which individuals make behavioural decisions that affect their survival and mating/reproductive success. The degree of inter-individual variation in behaviour expressed in a given population should depend in part on how and to what degree individuals adjust their behavioural decisions in response to different social contexts, so as to maximize individual fitness.
My research programme combines both the experimental and comparative approaches, in both the laboratory and field, and the use of mathematical modeling, microsatellite genotyping methods, and computer-based video technologies to test hypotheses about the evolution of context-dependent behaviour within the framework sexual selection, social learning, and social network theories. We use a variety of species (mainly fishes; see exemplar photos below) as model study systems as appropriate. Three general lines of inquiry are ongoing in collaboration with students, postdoctoral fellows and colleagues.
(1). Behavioural ecology of sexual selection and mating decisions Individuals do not mate randomly in most animal species. Most commonly, females actively choose their mates and males compete for access to mating opportunities (males can also be choosy in some species); sexual conflict between the sexes is common. As a result, variance in mating and reproductive success in both sexes exists to varying degree within and between populations, which in turn affects the intensity of sexual selection in populations and the evolution of sexually-related phenotypic traits. The contribution of social factors to variation in sexual behaviour, and to the intensity of sexual selection, within populations is of considerable interest. We are therefore investigating the potential influences of certain social factors (e.g. sex ratio, group size, social familiarity with nearby conspecifics) (i) on the tendency of females to copy the observed mate choice of other females (i.e. mate-choice copying behaviour), (ii) on male mating tactics, and (iii) on the formation and maintenance of particular social associations among individuals, and the implications of such associations for social networks in natural populations and for the intensity of sexual selection.
(2). Behavioural ecology of social associations and group living Individual animals may live alone or in social groups of varying membership size and phenotypic composition. We are interested in further understanding the ecological and social factors that have favoured the evolution of group living. One approach being taken is to model theoretically and to quantify empirically the benefits and costs associated with the 'decisions' of individual fish to join or leave social groups (shoals), of which spatial position to occupy within a shoal (e.g. periphery or centre), and of which individuals to associate with socially. The effects of important ecological factors (e.g. predation risk, food abundance and parasites), phenotypic characteristics of individuals (e.g. body size, sex), social familiarity with one another, and kinship on such shoaling decisions are being investigated experimentally. We are also exploring individual recognition mechanisms, and the relationships between the formation and stability of individual social associations and social networks.
(3). Behavioural ecology of predator-prey relationships Selection favours behavioural adaptations in prey to avoid and escape predators and counter-adaptations in predators to detect and capture prey. We are interested in many aspects of predator-prey interactions, including predator choice of prey phenotypes and chemically-mediated antipredator behaviour. Of particular interest is risk-taking behaviour in prey and associated behavioural trade-offs. Individual animals typically vary along the “shy-bold” axis of “personality”. Bolder individuals tend to be consistently more exploratory and to take more risk than timid individuals. We are interested in understanding how such variability in boldness among individuals in a population arises and is maintained. Efforts are being directed at quantifying the fitness-related benefits and costs of being ‘timid’ or ‘bold’ and the heritability of boldness. We are also exploring potential correlations between boldness and other behavioural traits that strongly impact individual fitness (i.e. behavioural syndromes).
NOTE: I am presently semi-retired (as of July 2017) and no longer accepting new graduate students into my research group. I continue, however, being active with my research.