402 NORTH AMERICAN BIRDS. 



mer season, and towards dusk thousands of these birds and of C. tcxensis 

 and C. Jicnri/i might be seen flying iii towards the river from the prairies, 

 this one being tlie least common of the three. In Northern Florida it is 

 also a common species, and I have rarely received any collection of eggs 

 from that State without the eggs of this Ijird being found among tiiem. 

 They are known there as Bull-bats. 



In many of its habits, as well as in its well-marked generic distinctions, 

 this species exhibits so many and such well-marked difi'erences from the 

 Whippoorwill that there seem to be no good reasons for confounding two 

 birds so very unlike. It is especially much less nocturnal, and has, strictly 

 speaking, no claim to its common name,* as indicating it to be a bird of the 

 night, which it is not. It is crepuscular, rather than nocturnal, and even 

 this habit is more due to the flight of the insects upon which it feeds at 

 morning and at evening than to any organization of the bird rendering it 

 necessary. It may not unfrequently be seen on the wing, even in bright 

 sunny weather, at midday, in pursuit of its winged prey. This is especially 

 noticeable with such birds as are wont to frequent our large cities, which may 

 be seen throughout all hours of tlie day sailing high in the air. Generally, 

 however, it is most lively early in the morning and just before nightfall, 

 ■when its supply of insect food is most abundant. But it is never to be 

 found on the wing after dark. As soon as the twilight deepens into the 

 shades of night all retire to rest as regularly, if not at quite as early an 

 hour, as other birds in regard to the diurnal habits of which there is no 

 question. 



This species appears to be equally abundant throughout the fur countries, 

 where. Dr. Richardson states, few birds are better known. In the higher 

 latitudes to which these birds resort the sun does not set during their stay, 

 and all their jrarsuit of insects must be made by suuliglit. 



In the winter this species leaves the United States, retiring to Mexico, 

 Central America, and the northern portions of South America. Specimens 

 from ]\Iexico were in the Rivoli collection. They were taken b)* Barruel 

 in Nicaragua, by Salvin in Guatemala, in Jamaica by Gosse, and in Cuba by 

 both Lembeye and Gundlach. 



The movements, evolutions, and general habits of this species, in the pur- 

 suit of their prey, bear little resemblance to those of the Antrostomi, but 

 are much more like those of the Falconida: They fly high in the air, often 

 so high as to be hardly visible, and traverse the air, moving backward and 

 forward in the manner of a Hawk. At times they remain iierfectly station- 

 ary for several moments, and then suddenly and ra]iidly dart nlf, their wings 

 causing a very peculiar vibratory sound. As they fly they utter a very loud 

 and shrill cry which it is almost impossible to describe, but often appearing 

 to come from close at hand when the bird is high in the air. Richardson 

 compares this sound to the vibration of a tense cord in a violent gust of 

 wind. 



