Geographic variation in behaviour: an introduction

Environments vary across space and time, and behavioural divergence among populations is commonplace. Differences in behaviour may represent genetic divergence or phenotypic plasticity, and arise from abiotic or biotic factors. In turn, such differences in behaviour may promote reproductive isolation and speciation, and they may also influence how traits such as mating displays relate to fitness. With these realizations there has been an enormous increase in the number of studies and techniques used to study geographic variation in behaviour, especially since the publication of Foster and Endler’s (1999) book, Geographic Variation in Behavior: Perspectives on Evolutionary Mechanisms. The new body of work makes important contributions to our understanding of the patterns, processes, and consequences of geographic variation in behaviour. This work remains to be incorporated into mainstream evolutionary theory. For example, researchers still too often characterize species with single populations, and even in comparative studies researchers often use a single estimate for an entire species. This special collection originated from the symposium ‘Geographic Variation in Behaviour’ at the 2011 Annual Animal Behavior Society meeting in Bloomington, Indiana. Caitlin R. Gabor and Andrea S. Aspbury organized the symposium. As organizers of the symposium, and together with Rafael L. Rodríguez as editors of this special volume, our goal was to attract the best possible set of papers. All the contributed papers emphasize the connection between geographic variation and speciation, and provide empirical insights into this connection. The contributed papers also represent varied approaches to understanding animal behaviour – the different authors use diverse techniques and perspectives, and do so at varying taxonomic scales. With this collection we wish to understand how research on geographic variation in behaviour is shaping our understanding of the mechanisms that result in geographic variation and its contributions to reproductive isolation and speciation.