In addition to common nighthawks
, whip-poor-wills and chuck-will's-widows, five other species of goatsuckers live in North America: the lesser and Antillean nighthawks, buff-collared nightjar, common pauraque, and the common poorwill, one of only a handful of birds known to go into torpor, a state akin to mammalian hibernation.
Doppler radar results indicate that common nighthawks, when foraging, fly on average 23% faster than when measured by timing flight over a known distance.
Assuming that our Doppler measurement of flight speed is more precise, we conclude that common nighthawks do not forage at predicted minimum power speed, but at speeds nearer the predicted maximum range speed.
First, birds should attempt to minimize foraging costs and given that common nighthawks appear to be limited in the time available for foraging by light levels (e.
The results suggested that common nighthawks would not be able to meet their energy demands unless the estimates of daily energy requirements were too high (i.
In any event the faster speed means that the energetic demands on common nighthawks are even higher than we calculated, assuming only one prey is captured per sweep, thus strengthening the argument that these birds "trawl.
Prey selection by big brown bats (Eptesicus fuscus) and common nighthawks (Chordeiles minor).