Effects of weather on daily body mass regulation in wintering dunlin.
J Exp Biol
; 205(Pt 1): 109-20, 2002 Jan.
Article
em En
| MEDLINE
| ID: mdl-11818417
ABSTRACT
We investigated the influence of changes in weather associated with winter storms on mass balance, activity and food consumption in captive dunlin (Calidris alpina) held in outdoor aviaries, and compared the aviary results with weather-related body mass differences in free-living dunlin collected at Bolinas Lagoon, California. Captive birds fed ad libitum increased their body mass at higher wind speeds and lower temperatures, suggesting regulation of energy stores, whereas free-living birds exhibited patterns suggesting thermoregulatory limits on body mass regulation. Daily energy expenditure in aviary dunlin was 2.85 kJ g d(-1), or 2.8x basal metabolic rate (BMR), with thermostatic costs averaging 59 % of daily expenditure. Slight but significant increases in body mass and energy expenditure in captive birds on rainy days, adjusted for possible external water mass, suggested rainfall as a proximate cue in regulating daily body mass. Body mass changes under artificial rainfall indicated similar results, and field masses suggested that free-living birds have greater body mass on days with measurable rainfall. Increased activity costs under artificial rainfall were associated with an increase in maintenance activities, relative to controls. Whether activity costs increased on days with natural rates of rainfall was unclear. Our results are consistent with current hypotheses regarding the role of body mass regulation in providing insurance against increased starvation risk during deteriorating thermal or foraging conditions, or in reducing the costs of extra mass as conditions improve.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estações do Ano
/
Tempo (Meteorologia)
/
Aves
/
Peso Corporal
Limite:
Animals
Idioma:
En
Revista:
J Exp Biol
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Estados Unidos