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Dietary amino acids influence plumage traits and immune responses of male house sparrows, Passer domesticus, but not as expected

Poston, J P; Hasselquist, Dennis LU ; Stewart, I R K and Westneat, D F (2005) In Animal Behaviour 70(5). p.1171-1181
Abstract
Traits that influence social interactions (signals) are widely thought to be honest indicators of some underlying quality of their bearer. One hypothesis is that a signal and the bearer's immunocompetence are linked via a condition-dependent pathway. We tested this idea by measuring the effect of specific dietary components on the development of a melanin-based plumage signal and the production of antibodies in juvenile male house sparrows entering their first moult. We maintained sparrows on one of three artificial diets: high total protein, low total protein, or intermediate protein with the precursors of melanin, phenylalanine and tyrosine (PT), reduced by 50%. Diet did not affect survival or weight gain. Two aspects of male plumage... (More)
Traits that influence social interactions (signals) are widely thought to be honest indicators of some underlying quality of their bearer. One hypothesis is that a signal and the bearer's immunocompetence are linked via a condition-dependent pathway. We tested this idea by measuring the effect of specific dietary components on the development of a melanin-based plumage signal and the production of antibodies in juvenile male house sparrows entering their first moult. We maintained sparrows on one of three artificial diets: high total protein, low total protein, or intermediate protein with the precursors of melanin, phenylalanine and tyrosine (PT), reduced by 50%. Diet did not affect survival or weight gain. Two aspects of male plumage differed between treatments; the white wing bar was significantly smaller in low-protein males, and the black bib feathers had significantly higher reflectance in PT-reduced males. PT reductions had no effect on bib size. PT-reduced birds also produced more antibodies to diphtheria and tetanus antigens than did other subjects. After repeating the experiment using a better control and a different diet formula to compensate for an energy imbalance resulting from reduced PT levels, PT reduction again produced lighter bib feathers, but the effect of diet on antibody production disappeared. We conclude that the amino acid precursors to melanin affect melanin synthesis if scarce in the diet, but in this case, do not affect size, the most conspicuously variable aspect of the signal. We found no evidence of a condition-dependent link between melanin synthesis and immunocompetence. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Animal Behaviour
volume
70
issue
5
pages
1171 - 1181
publisher
Elsevier
external identifiers
  • wos:000233404000022
  • scopus:27144446340
ISSN
1095-8282
DOI
10.1016/j.anbehav.2005.02.015
language
English
LU publication?
yes
id
cf8f8393-905c-4695-aaea-4cc4ce5c337f (old id 149111)
date added to LUP
2007-06-25 15:40:12
date last changed
2017-08-20 03:46:50
@article{cf8f8393-905c-4695-aaea-4cc4ce5c337f,
  abstract     = {Traits that influence social interactions (signals) are widely thought to be honest indicators of some underlying quality of their bearer. One hypothesis is that a signal and the bearer's immunocompetence are linked via a condition-dependent pathway. We tested this idea by measuring the effect of specific dietary components on the development of a melanin-based plumage signal and the production of antibodies in juvenile male house sparrows entering their first moult. We maintained sparrows on one of three artificial diets: high total protein, low total protein, or intermediate protein with the precursors of melanin, phenylalanine and tyrosine (PT), reduced by 50%. Diet did not affect survival or weight gain. Two aspects of male plumage differed between treatments; the white wing bar was significantly smaller in low-protein males, and the black bib feathers had significantly higher reflectance in PT-reduced males. PT reductions had no effect on bib size. PT-reduced birds also produced more antibodies to diphtheria and tetanus antigens than did other subjects. After repeating the experiment using a better control and a different diet formula to compensate for an energy imbalance resulting from reduced PT levels, PT reduction again produced lighter bib feathers, but the effect of diet on antibody production disappeared. We conclude that the amino acid precursors to melanin affect melanin synthesis if scarce in the diet, but in this case, do not affect size, the most conspicuously variable aspect of the signal. We found no evidence of a condition-dependent link between melanin synthesis and immunocompetence.},
  author       = {Poston, J P and Hasselquist, Dennis and Stewart, I R K and Westneat, D F},
  issn         = {1095-8282},
  language     = {eng},
  number       = {5},
  pages        = {1171--1181},
  publisher    = {Elsevier},
  series       = {Animal Behaviour},
  title        = {Dietary amino acids influence plumage traits and immune responses of male house sparrows, Passer domesticus, but not as expected},
  url          = {http://dx.doi.org/10.1016/j.anbehav.2005.02.015},
  volume       = {70},
  year         = {2005},
}