The Influence of Parental Status on Courtship Effort in a Paternal Caring Fish

Abstract

It is widely assumed that caring for young limits the motivation of parents to seek additional mating opportunities. However, in situations where parental care does not involve direct provisioning of the offspring, but rather activities directed at the brood as a whole (e.g. guarding), it may be more efficient for parents to care for large numbers of young at once. This may be especially true for species with exclusive paternal care, with fathers that have recently acquired a brood of young potentially benefitting from vigorously courting prospective mates, so as to maximise their chances of attaining a large number of young to rear together. We experimentally tested this hypothesis in the three‐spined stickleback (Gasterosteus aculeatus), a fish with male only care. Contrary to our predictions, we found no evidence of any differences in courtship between recently spawned egg‐tending fathers and males that had not spawned. However, males that were permitted to spawn, but then had their eggs taken from them, courted less vigorously. Together, the results of our study suggest that the potential benefits of vigorous courtship in terms of acquiring additional young may be offset by additional costs faced by parental males.