Abstract

Parental care is costly, and theory suggests that caregivers should reduce parental investment or even stop caring altogether when the costs of caring are too high or the benefits too low. Brood cannibalism is one tactic by which parents can divert investment away from current offspring and towards potentially higher-quality future offspring, but the various selective factors underlying partial brood cannibalism and their relative importance remain poorly understood. Here we used the plainfin midshipman fish, Porichthys notatus, to concurrently examine three hypotheses for partial brood cannibalism and test whether cannibalism increases when (1) parental body condition is low, (2) brood sizes are large and/or (3) brood paternity is low. To investigate these predictions, we combine multiyear, multisite field data with genetic paternity testing and show that partial brood cannibalism is not related to low parental body condition or to large brood sizes, but rather is linked to low paternity. In particular, males that had taken over nests from other males, and were thus unrelated to the broods present in the new nests, consumed the largest number of young (similar to 15 or more eaten at a time). Our data also suggest that the consumption of only a few young (similar to 1-2 at a time) appears to be governed by other factors that are not clearly related to paternity. Overall, we highlight the utility of concurrently testing multiple hypotheses for partial brood cannibalism within the same system to better understand this otherwise puzzling behaviour. (C) 2019 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Keywords

cuckoldry; filial cannibalism; infanticide; male competition; microsatellite genotyping; parental care; toadfish

Published in

Animal Behaviour
2019, Volume: 153, pages: 41-48
Publisher: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD

UKÄ Subject classification

Behavioral Sciences Biology


Publication identifier

DOI: https://doi.org/10.1016/j.anbehav.2019.04.018

Permanent link to this page (URI)

https://res.slu.se/id/publ/119485