THE TRADE-OFF BETWEEN FORAGING AND COURTING IN MALE GUPPIES

For animals to maximize their fitness, they must be efficient at foraging and prolific at reproduction. These activities re often considered as distinct and separate and are therefore studied in isolation of other behaviour patterns. However, many animal species must simultaneously choose between foraging and opportunities to reproduce. One such animal is the guppy, Poecilia reticulata. Four groups of male guppies were presented with the simultaneous choice of courting a female or feeding. As predicted by a state-dependent model, male guppies always fed prior to courting the female. Although the length of time male guppies spent feeding was inversely related to the rate at which food was provided, they consumed more when food was provided at a lower rate. Female size did not influence the length of time males spent feeding, but did affect the number of males that engaged in courtship, except for the very largest females. These females were from a domesticated strain and received the same courtship activity as wild females that were approximately one-eighth their size. These data suggest that male guppies make state-dependent decisions, choosing first to ensure they have sufficient energy reserves before investing time and energy in courtship. © 1993 The Association for the Study of Animal Behaviour. All rights reserved.