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Titolo:
SEASONAL ACCLIMATIZATION OF THERMOREGULATION IN THE BLACK-CAPPED CHICKADEE
Autore:
COOPER SJ; SWANSON DL;
Indirizzi:
UTAH STATE UNIV,DEPT BIOL LOGAN UT 84322 UNIV S DAKOTA,DEPT BIOL VERMILLION SD 57069
Titolo Testata:
The Condor
fascicolo: 3, volume: 96, anno: 1994,
pagine: 638 - 646
SICI:
0010-5422(1994)96:3<638:SAOTIT>2.0.ZU;2-P
Fonte:
ISI
Lingua:
ENG
Soggetto:
DARK-EYED JUNCO; OXYGEN-CONSUMPTION; PARUS-ATRICAPILLUS; THERMOGENIC CAPACITY; GEOGRAPHIC-VARIATION; PASSER-DOMESTICUS; HOUSE SPARROW; WINTER; TEMPERATURE; METABOLISM;
Keywords:
BLACK-CAPPED CHICKADEE; PARUS ATRICAPILLUS; COLD TOLERANCE; MAXIMAL THERMOGENIC CAPACITY; STANDARD METABOLIC RATE; THERMOREGULATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
46
Recensione:
Indirizzi per estratti:
Citazione:
S.J. Cooper e D.L. Swanson, "SEASONAL ACCLIMATIZATION OF THERMOREGULATION IN THE BLACK-CAPPED CHICKADEE", The Condor, 96(3), 1994, pp. 638-646

Abstract

Black-capped Chickadees (Parus atricapillus) show behavioral adaptations (food caching, cavity roosting) and can undergo regulated bouts ofnocturnal hypothermia, both of which reduce costs associated with wintering in temperate latitudes. These adjustments could reduce the needfor the seasonal metabolic adjustments found in other small passerines that must deal with severe winter cold. We have examined this possibility by determining the extent of seasonal variation evident in chickadees concerning standard metabolic rate, metabolic response to temperature, cold resistance, and maximal thermogenic capacity (Vo(2)(sum)). Regression equations relating metabolism to air temperature below thermoneutrality did not differ significantly in either slope or Y-intercept between summer and winter, and neither did minimum thermal conductance for normothermic birds vary seasonally. Seasonal constancy in these parameters demonstrates the minor role that seasonal changes in insulation play in acclimatization in chickadees. However, winter birds tolerated cold stress far better than summer birds. This improved cold tolerance was associated with a significant increase in Vo(2)(sum) (36%) in winter relative to summer. Standard metabolic rates (SMR) were also significantly increased in winter birds compared to summer birds. Thus, Black-capped Chickadees show seasonal metabolic acclimatization similar to, or greater than, other temperate wintering passerines in addition to behavioral adaptations and nocturnal hypothermia.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/07/20 alle ore 07:11:40