Handling stress increases expression of male sexual behaviour in an amphibian with an explosive mating strategy

Abstract

AbstractExposure to stressors typically suppresses reproductive processes, including the expression of sexual behaviour. However, many animal species breed in extreme conditions where opportunities to mate in a given season are limited. In such species, stress‐induced suppression of reproduction would be maladaptive, especially if they also have short lifespans. Species with longer lifespans, but still limited mating opportunities in a given season, may be able to withstand a few missed breeding opportunities. We tested whether capture and handling would suppress male sexual behaviour in spotted salamanders (Ambystoma maculatum), a species with an explosive mating strategy but a relatively long lifespan. Males were captured as they migrated to breeding sites and were handled in a manner known to induce an increase in plasma corticosterone, a component of the stress response. Thirty min later, each male was paired with a freshly captured female for 60 min. Handled males deposited significantly more spermatophores than did control males. The mechanism for the increased sexual behaviour is unknown but may involve handling‐induced changes in stress hormones or reproductive hormones. Regardless of the mechanism whereby handling increased male sexual behaviour, our results support the hypothesis that stressors do not suppress male mating behaviour in a long‐lived species with limited opportunities to mate.