Metabolism and thermoregulation of individual and clustered long-fingered bats,Miniopterus schreibersii, and the implications for roosting

Abstract

Oxygen consumption of individual long-fingered bats, Miniopterus schreibersii, was measured at air temperatures (Tr) between 2 and 42°C and that of clusters of four and six bats between 5 and 30°C. BMR of individuals was estimated to be 2.29 ml O2 g 1 h-1 between 34 and about 38°C. M. schreibersii showed two different responses to Ta, either maintaining body temperature (Tb) by increasing metabolic rate, or allowing Tb to fall close to ambient temperature and conserving energy (torpor). Euthermic clusters of four and six bats had lower rates of mass-specific oxygen consumption and lower thermal conductances than individuals at equivalent temperatures and torpid clusters maintained a greater temperature differential between Tb and Ta. Lowest rates of metabolism were measured for euthermic bats at air temperatures higher than those available to them in their natural roost in summer, so typical roost temperatures result in metabolic rates that are about 2 4–3.1 times estimated BMR. Roost temperatures of M. s...