Hormone levels predict individual differences in reproductive success in a passerine bird.
Proc Biol Sci
; 278(1717): 2537-45, 2011 Aug 22.
Article
em En
| MEDLINE
| ID: mdl-21247953
ABSTRACT
Hormones mediate major physiological and behavioural components of the reproductive phenotype of individuals. To understand basic evolutionary processes in the hormonal regulation of reproductive traits, we need to know whether, and during which reproductive phases, individual variation in hormone concentrations relates to fitness in natural populations. We related circulating concentrations of prolactin and corticosterone to parental behaviour and reproductive success during both the pre-breeding and the chick-rearing stages in both individuals of pairs of free-living house sparrows, Passer domesticus. Prolactin and baseline corticosterone concentrations in pre-breeding females, and prolactin concentrations in pre-breeding males, predicted total number of fledglings. When the strong effect of lay date on total fledgling number was corrected for, only pre-breeding baseline corticosterone, but not prolactin, was negatively correlated with the reproductive success of females. During the breeding season, nestling provisioning rates of both sexes were negatively correlated with stress-induced corticosterone levels. Lastly, individuals of both sexes with low baseline corticosterone before and high baseline corticosterone during breeding raised the most offspring, suggesting that either the plasticity of this trait contributes to reproductive success or that high parental effort leads to increased hormone concentrations. Thus hormone concentrations both before and during breeding, as well as their seasonal dynamics, predict reproductive success, suggesting that individual variation in absolute concentrations and in plasticity is functionally significant, and, if heritable, may be a target of selection.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Prolactina
/
Reprodução
/
Corticosterona
/
Pardais
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Limite:
Animals
País/Região como assunto:
America do norte
Idioma:
En
Revista:
Proc Biol Sci
Assunto da revista:
BIOLOGIA
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Estados Unidos