168 THE CHIMNEY SWALLOW, OR AMERICAN SWIFT. 



the birds which we had procured, a hundred and fifteen in number, we found 

 only six females. Eighty-seven were adult males; of the remaining twenty- 

 two the sex could not be ascertained, and I had no doubt that they were 

 the young of that year's first brood, the flesh and quill-feathers being tender 

 and soft. 



Let us now make a rough calculation of the number that clung to the tree. 

 The space beginning at the pile of feathers and moulded exuviae, and ending 

 at the entrance of the hole above, might be fully 25 feet in height, with a 

 breadth of 15 feet, supposing the tree to be 5 feet in diameter at an average. 

 There would thus be 375 feet square of surface. Each square foot, allowing 

 a bird to cover a space of 3 inches by 1^, which is more than enough, judging 

 from the manner in which they were packed, would contain 32 birds. The 

 number of Swallows, therefore, that roosted in this single tree was 9000. 



I watched the motions of the Swallows, and when the young birds that 

 had been reared in the chimneys of Louisville, Jeifersonville, and the houses 

 of the neighbourhood, or the trees suited for the purpose, had left their native 

 recesses, I visited the tree on the 2nd day of August. I concluded that the 

 numbers resorting to it had not increased; but I found many more females 

 and young than males, among upwards of fifty, which were caught and 

 opened. Day after day I watched the tree. On the 13th of August, not 

 more than two or three hundred came there to roost. On the 18th of the 

 same month, not one did I see near it, and only a few scattered individuals 

 were passing, as if moving southward. In September I entered the tree at 

 night, but not a bird was in it. Once more I went to it in February, when 

 the weather was very cold; and perfectly satisfied that all these Swallows 

 had left our country, I finally closed the entrance, and left off visiting it. 



May arrived, bringing with its vernal warmth the wanderers of the air, 

 and I saw their number daily augmenting, as they resorted to the tree to 

 roost. About the beginning of June, I took it in my head to close the 

 aperture above, with a bundle of straw, which with a string I could draw off 

 whenever I might choose. The result was curious enough; the birds as usual 

 came to the tree towards night; they assembled, passed and repassed, with 

 apparent discomfort, until I perceived many flying off to a great distance, on 

 which I removed the straw, when many entered the hole, and continued to 

 do so until I could no longer see them from the ground. 



I left Louisville, having removed my residence to Henderson, and did not 

 see the tree until five years after, when I still found the Swallows resorting 

 to it. The pieces of wood with which I had closed the entrance had rotted, 

 or had been carried off, and the hole was again completely filled with exuviae 

 and mould. During a severe storm, their ancient tenement at length gave 

 way, and came to the ground. 



