Sperm numbers as a paternity guard in a wild bird

Rowe, Melissah, van Oort, Aaabel, Brouwer, Lyanne, Lifjeld, Jan T., Webster, Michael S., Welklin, Joseph F., and Baldassarre, Daniel T. (2022) Sperm numbers as a paternity guard in a wild bird. Cells, 11 (2). 231.

[img]
Preview
PDF (Published Version) - Published Version
Available under License Creative Commons Attribution.

Download (1MB) | Preview
View at Publisher Website: https://doi.org/10.3390/cells11020231
 
17


Abstract

Sperm competition is thought to impose strong selection on males to produce competitive ejaculates to outcompete rival males under competitive mating conditions. Our understanding of how different sperm traits influence fertilization success, however, remains limited, especially in wild populations. Recent literature highlights the importance of incorporating multiple ejaculate traits and pre-copulatory sexually selected traits in analyses aimed at understanding how selection acts on sperm traits. However, variation in a male’s ability to gain fertilization success may also depend upon a range of social and ecological factors that determine the opportunity for mating events both within and outside of the social pair-bond. Here, we test for an effect of sperm quantity and sperm size on male reproductive success in the red-back fairy-wren (Malurus melanocephalus) while simultaneously accounting for pre-copulatory sexual selection and potential socio-ecological correlates of male mating success. We found that sperm number (i.e., cloacal protuberance volume), but not sperm morphology, was associated with reproductive success in male red-backed fairy-wrens. Most notably, males with large numbers of sperm available for copulation achieved greater within-pair paternity success. Our results suggest that males use large sperm numbers as a defensive strategy to guard within-pair paternity success in a system where there is a high risk of sperm competition and female control of copulation. Finally, our work highlights the importance of accounting for socio-ecological factors that may influence male mating opportunities when examining the role of sperm traits in determining male reproductive success.

Item ID: 71254
Item Type: Article (Research - C1)
ISSN: 2073-4409
Related URLs:
Copyright Information: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)
Date Deposited: 27 Jan 2022 23:02
FoR Codes: 31 BIOLOGICAL SCIENCES > 3104 Evolutionary biology > 310405 Evolutionary ecology @ 40%
31 BIOLOGICAL SCIENCES > 3109 Zoology > 310901 Animal behaviour @ 30%
31 BIOLOGICAL SCIENCES > 3109 Zoology > 310903 Animal developmental and reproductive biology @ 30%
SEO Codes: 28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280102 Expanding knowledge in the biological sciences @ 100%
Downloads: Total: 17
Last 12 Months: 9
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page