Population differences in spatial learning in three-spined sticklebacks

In a changing environment, learning and memory are essential for an animal's survival and reproduction. The role played by the environment in shaping learning and memory is now attracting considerable attention. Until now studies have tended to compare the behaviour of two, or at best a few species, but interspecific comparisons can be misleading as many life history variables other than environment may differ between species. Here we report on an experiment designed to determine how learning varies between different populations of the same species, the three-spined stickleback. We found differences between the populations in their ability to solve a spatial task and also in the spatial strategies they used. A second simple learning task showed that these differences were not the result of gross differences in learning ability or adaptation to laboratory conditions. We discuss these results and suggest that the behavioural differences may relate to features of the respective habitats from which the fish were sampled.