Male interactions and female mate choice in the sand goby, Pomatoschistus minutus

To examine whether male-male interactions constrain female choice in the sa nd goby, we compared female preferences expressed under three conditions th at varied in the degree of male-male interaction with matings that resulted from free interactions. The experiment consisted of two phases. In the ini tial phase a transparent divider separated the female from two males. Durin g this stage the males were either isolated by an opaque divider, had visua l contact through a transparent divider, or were allowed full interaction b y having access to each other's compartments. The second phase of the exper iment was initiated by the removal of all dividers and terminated when the female spawned with one of the males. When there was no initial contact bet ween the males, females spawned with the male they showed a preference for in the first phase of the experiment. In the other two male treatments, fem ales were inconsistent in their spawning choice. Females did not seem to ch oose dominant males and neither did male aggressive interactions seem to li mit a female's possibilities to spawn with a particular male. The results s uggest that male-male interaction may affect the ability of females to eval uate males, in part because of courtship interference between males. Male-m ale interaction therefore seems to impede female choice and consequently ma y hinder sexual selection due to mate choice. (C) 2001 The Association for the Study of Animal Behaviour.