166 Retrospective Criticistn. 



particularly as regards their powers of smell and sight, which 

 were continued, with little intermission, till the 31st. Written 

 invitations were sent to all the professors of the two medical 

 colleges in this city, to the officers and some of the members 

 of the Philosophical Society, and such other individuals as we 

 believed might take an interest in the subject. Although 

 Mr. Audubon was present during most of this time, and was 

 wiUing to render any assistance required of him, yet he 

 desired that we might make the experiments ourselves, that 

 we might adopt any mode that the ingenuity or experience of 

 others could suggest in arriving at the most correct conclu- 

 sions. The manner in which these experiments were made, 

 together with the result, I now proceed to detail. 



There were three points on which the veracity of Mr. Au- 

 dubon had been assailed : first, whether the vulture is grega- 

 rious ; secondly, whether he feeds on fresh as well as putrid 

 flesh; thirdly, whether he is attracted to his food by the eye 

 or the scent ? To these queries, not only in justice to the 

 American ornithologist, but to aid the cause of natural science, 

 our enquiries were directed. First, whether the vultures of 

 this country are gregarious ? — That vultures, during the 

 breeding season, and occasionally at other times, fly singly, is 

 well known ; but such is also the case with all our birds that 

 usually keep in flocks ; witness the wild pigeon (Columba 

 migratoria) and the robin (Turdus migratbrius), and many of 

 our water birds. But that our vultures are gregarious, in the 

 true sense of the word, is a fact well established. In most 

 cases, in the interior of our state, as well as in the environs of 

 this city, considerable numbers are found in company, from 

 three or four to forty or fifty. They hunt for their prey in 

 company ; they feed together on the same carrion ; they per- 

 form their gyrations in great numbers together, and they roost 

 together. I have visited their roosting-places ; a sight well 

 worth travelling many miles to observe. In some deep swamp, 

 or occasionally in high ground, surrounded by a thicket 

 of vines and thorny shrubs, usually composed of ^lizyphus 

 volubilis, and several species of 6^milax and JKubus, the 

 buzzards resort for years together to spend their nights. 

 Here, on some dead tree, and frequently on several that may 

 be standing near each other, they are crowded so close to- 

 gether that one or two hundred may be counted on a tree, and 

 frequently thirty or forty on a single branch. The ground 

 and bushes, within a certain extent, are covered with the ex- 

 crements ; which, by their acridity, htive destroyed the whole 

 undergrowth of shrubs and plants and every blade of grass ; 

 so that the surface presents an appearance of having received 

 several thick coatings of whitewash. 



