Advanced

Dressed to impress : breeding plumage as a reliable signal of innate immunity

Pardal, Sara LU ; Alves, José A.; Mota, Paulo G. and Ramos, Jaime A. (2018) In Journal of Avian Biology 49(7).
Abstract

Animal signals involved in sexual selection are often indicators of individual quality. The assumption that sexual characters such as breeding plumage may indicate immune state has rarely been tested in free-living migratory birds, particularly in relation to innate immunity. If sexual characters indeed reflect immune condition, then these could be used to evaluate individual quality. Melanin is a common pigment used in animal communication that mitigates the effects of oxidative stress and has positive effects on energy homeostasis, important functions during the strenuous activity of long-distance flights. However, melanin is also immunosuppressive, and the melanised patches of breeding plumage may to some extent compromise immune... (More)

Animal signals involved in sexual selection are often indicators of individual quality. The assumption that sexual characters such as breeding plumage may indicate immune state has rarely been tested in free-living migratory birds, particularly in relation to innate immunity. If sexual characters indeed reflect immune condition, then these could be used to evaluate individual quality. Melanin is a common pigment used in animal communication that mitigates the effects of oxidative stress and has positive effects on energy homeostasis, important functions during the strenuous activity of long-distance flights. However, melanin is also immunosuppressive, and the melanised patches of breeding plumage may to some extent compromise immune responsiveness. We studied melanin-based secondary sexual characters (SSC) in a long-distance migratory wader, the black-tailed godwit Limosa limosa, and found that breeding plumage features of male and female godwits are linked to components of innate immunity. Males with a larger colour extension had higher circulating levels of haptoglobin and hemolysis activity, while they also presented a lower body condition; whereas females presented a negative trend between colour and bar extension and hemolysis activity, and a positive trend for natural antibodies. The association between signal, immune state and physical condition in males suggests a cost for signal production and immune condition during prenuptial migration. Sex differences in how signals relate with immune capacity are a likely consequence of sex-specific signalling roles and energy demands. Our results indicate that male godwit breeding plumage reflects innate immunity state, and is therefore a likely signal for females to use during mate choice as an honest indicator of male's capacity to allocate energy/resources to both expensive traits during periods of energetic constraint.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
black-tailed godwit, migration, sexual secondary characters
in
Journal of Avian Biology
volume
49
issue
7
publisher
Federation of European Neuroscience Societies and Blackwell Publishing Ltd
external identifiers
  • scopus:85050767850
ISSN
0908-8857
DOI
10.1111/jav.01579
language
English
LU publication?
yes
id
86d22c36-c03d-488c-926a-02d07f7f2c45
date added to LUP
2018-09-12 14:46:12
date last changed
2019-02-20 11:26:39
@article{86d22c36-c03d-488c-926a-02d07f7f2c45,
  abstract     = {<p>Animal signals involved in sexual selection are often indicators of individual quality. The assumption that sexual characters such as breeding plumage may indicate immune state has rarely been tested in free-living migratory birds, particularly in relation to innate immunity. If sexual characters indeed reflect immune condition, then these could be used to evaluate individual quality. Melanin is a common pigment used in animal communication that mitigates the effects of oxidative stress and has positive effects on energy homeostasis, important functions during the strenuous activity of long-distance flights. However, melanin is also immunosuppressive, and the melanised patches of breeding plumage may to some extent compromise immune responsiveness. We studied melanin-based secondary sexual characters (SSC) in a long-distance migratory wader, the black-tailed godwit Limosa limosa, and found that breeding plumage features of male and female godwits are linked to components of innate immunity. Males with a larger colour extension had higher circulating levels of haptoglobin and hemolysis activity, while they also presented a lower body condition; whereas females presented a negative trend between colour and bar extension and hemolysis activity, and a positive trend for natural antibodies. The association between signal, immune state and physical condition in males suggests a cost for signal production and immune condition during prenuptial migration. Sex differences in how signals relate with immune capacity are a likely consequence of sex-specific signalling roles and energy demands. Our results indicate that male godwit breeding plumage reflects innate immunity state, and is therefore a likely signal for females to use during mate choice as an honest indicator of male's capacity to allocate energy/resources to both expensive traits during periods of energetic constraint.</p>},
  articleno    = {e01579},
  author       = {Pardal, Sara and Alves, José A. and Mota, Paulo G. and Ramos, Jaime A.},
  issn         = {0908-8857},
  keyword      = {black-tailed godwit,migration,sexual secondary characters},
  language     = {eng},
  month        = {07},
  number       = {7},
  publisher    = {Federation of European Neuroscience Societies and Blackwell Publishing Ltd},
  series       = {Journal of Avian Biology},
  title        = {Dressed to impress : breeding plumage as a reliable signal of innate immunity},
  url          = {http://dx.doi.org/10.1111/jav.01579},
  volume       = {49},
  year         = {2018},
}