Do free-ranging Common Nighthawks enter torpor?

The ability of free-ranging Common Nighthawks to enter torpor was evaluated. Nighthawks were captured by mist nets from the vicinity of Okanagan Falls in British Columbia and were subsequently weighed using an electronic balance. Thehawks' skin temperature was checked and recorded every 20 minutes between sunset and sunrise to determine the onset of torpor. Results revealed that Common Nighthawks are not physiologically adapted to enter torpor as a means ofenergy conservation.