Seasonal variation in the resting metabolic rate of male wood mice Apodemus sylvaticus from two contrasting habitats 15 km apart

摘要: Diurnal and nocturnal resting metabolic rates of winter- summer-acclimatized adult male wood mice Apodemus sylvaticus from two adjacent populations, 15 km apart, were measured. One population lived in deciduous woodland, experienced a narrower daily range temperatures than the second population, which inhabited maritime sand-dunes. Ambient temperature body mass had significant effects on metabolism mice, excluding winter-acclimatized sand-dune animals where only explained amounts observed variation. Only this latter group could thermoneutral zone be determined, with lower critical ca. 25 °C 0.155 W. Nocturnal significantly greater diurnal levels. Winter acclimatization was associated reductions thermal conductance metabolism, thus minimizing energy expenditure at rest. Site differences thermoregulatory strategies found winter, conductances remained similar but sand-dunes those woodland. influenced by factors addition to photoperiod. Intra-specific individual variations as shown study, potentially have pronounced effect free-living animal.