Energetic constraints drive sex‐specific parental care in the monomorphic Leach's storm‐petrel Hydrobates leucorhous

Sex‐specific parental care in dimorphic species may be unsurprising, but why this occurs in monomorphic species is more puzzling. To date, however, there have been few examinations of the causes of this phenomenon. Here, we evaluated possible explanations of sex‐specific provisioning in the monomorp...

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Bibliographic Details
Published in:Journal of Avian Biology
Main Authors: Chris W. Tyson, Sarah L. Jennings, Brian A. Hoover, Amy Miles
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2022
Subjects:
Online Access:https://doi.org/10.1111/jav.02904
https://doaj.org/article/ddd96ef217454992a8afd6ff8398ca54
Description
Summary:Sex‐specific parental care in dimorphic species may be unsurprising, but why this occurs in monomorphic species is more puzzling. To date, however, there have been few examinations of the causes of this phenomenon. Here, we evaluated possible explanations of sex‐specific provisioning in the monomorphic Leach's storm‐petrel Hydrobates leucorhous (until recently Oceanodroma leucorhoa). We tracked the chick‐rearing behavior of 74 mated pairs using an automated nest monitoring system and collected daily measurements of chick growth. We found that males provisioned more frequently and made a larger overall contribution to chick feeding than females. Within‐individual trip duration was more variable for females, suggesting that they were alternating to a greater degree between short, energetically taxing trips that prioritize chick care and longer, recovery trips that prioritize self‐care. Moreover, females were more likely to embark on longer trips after completing a short trip and after encountering a chick in good condition. Males, however, appeared better able to perform repeated short trips that resulted in more frequent provisioning as well as greater amounts overall. These findings are consistent with the explanation that energetic constraints on females give rise to male‐biased, sex‐specific provisioning in a monomorphic species and are likely to explain similar patterns in other long‐lived species where adult survival is high.