Context-dependent response to red coloration in stickleback

Although Tinbergen found that red nuptial coloration of male three-spined stickleback, Gasterosteus aculeatus, elicited attack by other males, subsequent researchers have had difficulty replicating his results (Tinbergen 1948, Wilson Bull., 60, 6-51; 1951, The Study of Instinct. Oxford: Oxford University Press). Rowland et al. (1995, Anim. Behav., 50, 267-272) found that males tested in neutral tanks attacked a moderately coloured video image of a conspecific male more than either a bright or dull image in simultaneous presentations. These results suggest that a dual-effect process representing an interaction between aggression and fear might determine attack response. Based on this hypothesis, males tested in home tanks should attack the video images more than males tested in neutral tanks and should attack the brighter images most because their attack:fear ratio is higher. Males in their own territories spent more time attacking video images than males in neutral tanks. Males in their own territories also spent more time attacking the brighter image than they spent attacking either the moderate or the dull image. These results demonstrate the influence of spatial location on the response of male stickleback to rivals. Furthermore, a dual-effect model provides a heuristic tool for understanding the agonistic behaviour of male stickleback. (C) 1996 The Association for the Study of Animal Behaviour