Female plumage spottiness and parasite resistance in the barn owl (Tyto alba)

Détails

ID Serval
serval:BIB_03D5F1A627D6
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Female plumage spottiness and parasite resistance in the barn owl (Tyto alba)
Périodique
Behavioral Ecology
Auteur(s)
Roulin A., Riols C., Dijkstra C., Ducrest A. L.
ISSN
1045-2249
Statut éditorial
Publié
Date de publication
2001
Peer-reviewed
Oui
Volume
12
Numéro
1
Pages
103-110
Langue
anglais
Résumé
The hypothesis that extravagant ornaments signal parasite resistance has received support in several species for ornamented males but more rarely for ornamented females. However, recent theories have proposed that females should often be under sexual selection, and therefore females may signal the heritable capacity to resist parasites. We investigated this hypothesis in the socially monogamous barn owl, Tyto alba, in which females exhibit on average more and larger black spots on the plumage than males, and in which males were suggested to choose a mate with respect to female plumage spottiness. We hypothesized that the proportion of the plumage surface covered by black spots signals parasite resistance. In line with this hypothesis, we found that the ectoparasitic fly, Carnus hemapterus, was less abundant on young raised by more heavily spotted females and those flies were less fecund. In an experiment, where entire clutches were cross-fostered between nests, we found that the fecundity of the flies collected on nestlings was negatively correlated with the genetic mother's plumage spottiness. These results suggest that the ability to resist parasites covaries with the extent of female plumage spottiness. Among females collected dead along roads, those with a lot of black spots had a small bursa of Fabricius. Given that parasites bigger the development of this immune organ, this observation further suggests that more spotted females are usually less parasitized. The same analyses performed on male plumage spottiness all provided non-significant results. To our knowledge, this study is the first one showing that a heritable secondary sexual characteristics displayed by females reflects parasite resistance.
Mots-clé
bursa of Fabricius, Carnus hemapterus, fecundity, female plumage ornamentation, good gene, parasite resistance, Tyto alba
Web of science
Création de la notice
24/01/2008 18:42
Dernière modification de la notice
03/03/2018 13:21
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