Condition-dependent signaling affects male sexual attractiveness in field crickets, Gryllus campestris

The condition dependence of sexually selected traits is an important assumption of sexual selection theory. Several laboratory studies have documented a positive relationship between food availability, body condition, and sexual display. However, these studies might not reflect the resource allocation between body maintenance, reserves, and the sexually selected trait under natural conditions. Further, the effect of condition-dependent signaling on female mate choice has hardly been investigated experimentally in the field. We therefore investigated the effect of food availability on body condition, calling behavior, and sexual attractiveness of male field crickets, Gryllus campestris, under field conditions. Food availability was manipulated for individual males by supplementing food in a confined area close to the burrow. Food-supplemented males showed a significant increase in body condition, whereas the opposite was found in the control males. Males receiving extra food called more frequently, whereas the calling-song characteristics were not affected by the treatment. Further, food-supplemented males attracted more females than did control males, and their higher attractiveness was partly explained by their superior calling rate. Our study thus indicates condition-dependent signaling as an important determinant of the sexual attractiveness of males to females under natural condition.