Free-ranging common nighthawks use torpor

摘要

Bouts of torpor are characterized by substantial reductions in body temperature and metabolic rate. Many birds in the order Caprimulgiformes use torpor; however, there is conflicting evidence whether or not Common Nighthawks (Chordeiles minor) have this ability. The purpose of our study was to examine whether free-ranging nighthawks enter torpor. Three out of eight birds that were monitored entered torpor on a total of four occasions. Our results suggest that torpor is not used as commonly as it is in other species of Caprimulgids providing incentive for further research to explain the ecological determinants of torpor use in Caprimulgids