Compensation for Injury? Modified multi-modal courtship of wolf spiders following autotomy of signalling appendages

Abstract

Male Schizocosa ocreata wolf spiders court females using displays that involve dramatic waving motions of their ornamented forelegs. In nature males are often found missing one, and sometimes both, of these legs. We here find that, when exposed to female draglines, males missing these signalling appendages perform a high intensity courtship element (‘jerky tapping’) at a greater rate than intact males. Loss of forelegs was also associated with changes in chemoexploration activity, tendency to stand stationary, and performance of a low intensity courtship element (‘tapping’). The age of the virgin female from which draglines were collected also had an important influence on male courtship behaviour; males on the draglines of old females were less likely to court and, if they did court, did so at a lower rate. These data indicate that courtship behaviour of male S. ocreata is flexible, varying both with the state of the male himself and the state of the female whose draglines he has encountered. Such individual courtship flexibility raises challenging questions of what processes and trade-offs underlie male courtship decision-making, and whether autotomy-induced changes in courtship activity represent adaptive compensation.