1 1(Brain Behavior Research Center, Department of Psychiatry, University of California, San Francisco, Sonoma Developmental Center, Eldridge, CA 95431, U.S.A, Bodega Marine Laboratory, University of California, Davis, Bodega Bay, CA 94923,
Sticklebacks presented with a clear glass tube filled with live brine shrimp will initially attempt to capture them; however, the response wanes within minutes. In the case of females, the rate of initial response is enhanced and the rate of waning is influenced by the state of the female (gravid females are more responsive) and by the density of the prey (greater density results in greater responsiveness). The predatory-response habituation differs from habituation of territorial aggression and courtship in that the pre-decremental, incremental process is absent. In common with habituation of territorial aggression but not with courtship, there is little short-term recovery of the response. The differences are consistent with different functional requirements for an experience-based inhibitory mechanism involved in the modulation of stickleback behaviour.