title: Genetics, local environment and health as factors influencing plasma carotenoids in wild American kestrels (Falco sparverius).
abstract: Carotenoids are important as pigments for bright coloration of animals, and as physiologically active compounds with a wide array of health-related functions. Carotenoid-dependent coloration may have evolved as a signal to conspecifics; however, factors that may limit availability of carotenoids are poorly known. We investigated how the acquisition of carotenoids may be constrained by availability in the environment, diet, genetic make-up and health status of wild American kestrels (Falco sparverius). Plasma concentrations of siblings at the time of fledging showed a high degree of resemblance; however, a cross-fostering experiment revealed that variance was largely explained by nest of rearing, rather than nest of origin, thus indicating a low genetic component. A multivariate analysis of attributes of nestlings (sex, size, plasma proteins, immune function), parental reproduction (laying date, clutch size) and rearing conditions (brood size, size hierarchy, nestling mortality) showed only a small significant effect of leucocyte differentials on carotenoid concentrations of nestlings. A strong environmental effect on plasma carotenoids was demonstrated by levels of adult kestrels being correlated within mated pairs, and having a significant association with the abundance of voles, the primary prey species, per territory.
authors.affiliation: Department of Biology, University of Saskatchewan, Saskatoon, Canada. bortolotti@sask.usask.ca
authors.forename: G R
authors.initials: GR
authors.lastname: Bortolotti
authors.forename: J L
authors.initials: JL
authors.lastname: Tella
authors.forename: M G
authors.initials: MG
authors.lastname: Forero
authors.forename: R D
authors.initials: RD
authors.lastname: Dawson
authors.forename: J J
authors.initials: JJ
authors.lastname: Negro
mesh_terms: D000818:Animals; D000835:Animals, Wild; D002338:Carotenoids / Q000097:blood*; D004777:Environment; D005247:Feeding Behavior; D006304:Health Status; D020304:Raptors / Q000097:blood* / Q000235:genetics / Q000502:physiology
chemical_list: D002338:Carotenoids