Since 2016 we have been using small islands in the Bahamas as a study system to conduct field experiments to unravel major questions in behavioral and evolutionary ecology. Can animal populations rapidly evolve to adapt to new selective pressures? What is the importance of individual variation in behavior to cope with these novel selective pressures? Do rapid behavioral shifts cascade into changes in trophic networks?
Recent times have seen increased interest in the ecological and evolutionary consequences of consistent individual differences in behavior but the lack of experimental evidence that natural selection acts on among-individual variation in behavior has remained a major obstacle to study this question.
We examine natural selection in risk taking behavior by means of an large-scale field experiment where we manipulated predation pressure (presence vs. absence of a ground predator) in a set of experimentally established island populations of Anolis sagrei in the Caribbean. This ongoing experiment provided experimental evidence that (1) among-individual variation in risk-taking behavior determines differential survival of Anolis under different predation regimes and (2) selection on behavior occurs simultaneously, and independently, to selection in functionally relevant morphological traits. This ongoing experiment has now become a long-term study of contemporary evolution.