Epaulet size and current condition in red-winged blackbirds : Examining a semistatic signal, Testosterone, Immune function, And parasites
(2015) In Physiological and Biochemical Zoology 88(1). p.11-21- Abstract
Some sexually selected signals are thought to convey information about the current condition and genetic/epigenetic quality of the individual signaling, including the ability to resist parasites. However, it is unclear whether semistatic sexual signals that develop periodically and remain stable over protracted periods, such as avian breeding plumage, can relate to measures of current condition and health. We examined a semistatic signal (wing epaulet size) in male redwinged blackbirds (Agelaius phoeniceus) during the breeding season and looked for relationships between this trait and circulating testosterone (T), hematocrit, bacteriakilling ability (BKA) of the blood, and the infection status, richness, and abundance of four functional... (More)
Some sexually selected signals are thought to convey information about the current condition and genetic/epigenetic quality of the individual signaling, including the ability to resist parasites. However, it is unclear whether semistatic sexual signals that develop periodically and remain stable over protracted periods, such as avian breeding plumage, can relate to measures of current condition and health. We examined a semistatic signal (wing epaulet size) in male redwinged blackbirds (Agelaius phoeniceus) during the breeding season and looked for relationships between this trait and circulating testosterone (T), hematocrit, bacteriakilling ability (BKA) of the blood, and the infection status, richness, and abundance of four functional categories of parasite. We found that epaulet size was positively related to circulating levels of T and ectoparasite infections. We found no relationships between T and parasite infections. In adult males there was a negative relationship between T and BKA, whereas in yearling males there was no relationship. We found no evidence for a general reduction in immunocompetence in males with larger epaulets but rather an increase in susceptibility to specific types of parasites. Our results suggest that semistatic signals can be linked to measures of current condition, and we postulate that these relationships are modulated via activity levels related to breedingseason activities.
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- author
- Merrill, Loren ; Stewart, Tara E. ; González-Gómez, Paulina L. ; O’Loghlen, Adrian L.O. ; Wingfield, John C ; Ellis, Vincenzo A. LU and Rothstein, Stephen I.
- publishing date
- 2015
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physiological and Biochemical Zoology
- volume
- 88
- issue
- 1
- pages
- 11 pages
- publisher
- University of Chicago Press
- external identifiers
-
- pmid:25590590
- scopus:84920675964
- ISSN
- 1522-2152
- DOI
- 10.1086/679475
- language
- English
- LU publication?
- no
- id
- 7cce3569-8625-44fc-a57c-5feb55f5e1fe
- date added to LUP
- 2017-05-09 17:14:03
- date last changed
- 2024-02-12 18:37:54
@article{7cce3569-8625-44fc-a57c-5feb55f5e1fe,
abstract = {{<p>Some sexually selected signals are thought to convey information about the current condition and genetic/epigenetic quality of the individual signaling, including the ability to resist parasites. However, it is unclear whether semistatic sexual signals that develop periodically and remain stable over protracted periods, such as avian breeding plumage, can relate to measures of current condition and health. We examined a semistatic signal (wing epaulet size) in male redwinged blackbirds (Agelaius phoeniceus) during the breeding season and looked for relationships between this trait and circulating testosterone (T), hematocrit, bacteriakilling ability (BKA) of the blood, and the infection status, richness, and abundance of four functional categories of parasite. We found that epaulet size was positively related to circulating levels of T and ectoparasite infections. We found no relationships between T and parasite infections. In adult males there was a negative relationship between T and BKA, whereas in yearling males there was no relationship. We found no evidence for a general reduction in immunocompetence in males with larger epaulets but rather an increase in susceptibility to specific types of parasites. Our results suggest that semistatic signals can be linked to measures of current condition, and we postulate that these relationships are modulated via activity levels related to breedingseason activities.</p>}},
author = {{Merrill, Loren and Stewart, Tara E. and González-Gómez, Paulina L. and O’Loghlen, Adrian L.O. and Wingfield, John C and Ellis, Vincenzo A. and Rothstein, Stephen I.}},
issn = {{1522-2152}},
language = {{eng}},
number = {{1}},
pages = {{11--21}},
publisher = {{University of Chicago Press}},
series = {{Physiological and Biochemical Zoology}},
title = {{Epaulet size and current condition in red-winged blackbirds : Examining a semistatic signal, Testosterone, Immune function, And parasites}},
url = {{http://dx.doi.org/10.1086/679475}},
doi = {{10.1086/679475}},
volume = {{88}},
year = {{2015}},
}