A COST OF SEXUAL HARASSMENT IN THE GUPPY, POECILIA-RETICULATA

Male guppies in wild Trinidadian populations devote a large proportion of their time to pursuing females, and females, as a result, are freq uent targets of sneaky mating attempts. In this paper we demonstrate a cost, in terms of lost feeding opportunities, to these female recipie nts of sexual harassment. An experiment in pools of a Trinidadian stre am manipulated sex ratio and fish density within the ranges naturally occurring in the system. We found that sexual harassment (from males) led to a 25% decrease in foraging beyond that which occurred as a resu lt of female competition. Because the fecundity of female fish is a pr oduct of their feeding success, reductions in food intake have potenti ally serious fitness consequences.