Female colour polymorphism covaries with reproductive strategies in the tawny owl Strix aluco

Details

Ressource 1Request a copy Under indefinite embargo.
UNIL restricted access
State: Public
Version: author
Serval ID
serval:BIB_658423642C6E
Type
Article: article from journal or magazin.
Collection
Publications
Title
Female colour polymorphism covaries with reproductive strategies in the tawny owl Strix aluco
Journal
Journal of Avian Biology
Author(s)
Roulin A., Ducret B., Ravussin P. A., Altwegg R.
ISSN
0908-8857
Publication state
Published
Issued date
2003
Peer-reviewed
Oui
Volume
34
Number
4
Pages
393-401
Language
english
Abstract
Variation in coloration with a strong underlying genetic basis is frequently found in birds, insects, anurans, molluscs and plants. Although such a variation can be large, little is known about its functional value. Correlative data, however, can help suggest testable hypotheses about potential covariation between reproductive parameters and a colour polymorphism displayed by individuals belonging to a single population. In this context, we studied two Swiss populations of tawny owls Strix aluco, a polymorphic species that varies in coloration from reddish-brown to grey. Observations in the first population showed that although greyer females had shorter tarsi, they produced heavier offspring in two of three years. Pairing with respect to plumage coloration was not significantly disassortative, indicating that these correlations were probably not inflated by plumage coloration of the mate. In the second population, where breeding females had been monitored for 14 years, the proportion of all breeding females that were reddish-brown was greater in years when the breeding density was lower. Capture-recapture analyses show that the latter result is explained by the fact that greyish females bred less often than reddish-brown females, although their survival probability was similar. The number of greyer breeding females was greater when spring/summer temperatures were lower. When combined, the results from the two populations lend support to the hypothesis that grey females do not breed every year, but produce offspring of higher quality. Whatever the mechanism underlying the correlations reported in this study, colour polymorphism in female tawny owls appears to reflect some components of individual quality.
Web of science
Create date
24/01/2008 17:42
Last modification date
20/08/2019 14:21
Usage data