Patterns of age-related change in reproductive effort differ in the pre-natal and post-natal periods in a long-lived mammal.
J Anim Ecol
; 85(6): 1540-1551, 2016 Nov.
Article
em En
| MEDLINE
| ID: mdl-27448960
ABSTRACT
Age-related changes in maternal reproductive allocation for long-lived species are a key prediction from life-history theory. Theoretical and empirical work suggests that allocation may increase with age due to constraint (increases with experience) or restraint (increases with age in the face of declining residual reproductive value), and may decrease among the oldest aged animals due to senescence in reproductive function. Here, we use a hierarchical modelling approach to investigate the age-related patterns of change in maternal reproductive effort in the Weddell seal, a long-lived marine mammal with a protracted period of maternal care during which mothers allocate a large proportion of body mass while feeding little. We find that maternal allocation increases with age for young mothers during both the pre-natal and post-natal periods. In contrast, older mothers demonstrate a senescent decline in pre-natal allocation but allocate more of their declining resources to their offspring during the post-natal period. We also find strong evidence for the importance of individual effects in reproductive allocation among mothers some mothers consistently produce heavier (or lighter) pups than expected. Our results indicate that maternal allocation changes over a mother's reproductive life span and that age-specific differences differ in notable ways in pre-natal and post-natal periods.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peso Corporal
/
Focas Verdadeiras
/
Metabolismo Energético
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
J Anim Ecol
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos