NIDIFICATTON. 433 



none but the red-headed urubu is to be seen. The former swarm 

 in Port-of- Spain, and, from the tops of houses they are con- 

 stantly on the watch for the smallest prey which may fall in the 

 streets ; but never is there seen among them a red-headed urubu. 

 Whenever, in the country, some dead animal attracts the vultures, 

 both species assemble in a band, and seem to act on good 

 terms. 



The habitat of birds, therefore, is not determined by the ali- 

 mentary substances which suit them : there are other secondary 

 but indispensable conditions which escape observation. 



NlDIFICATION. 



The study of the constructive instinct in birds would un- 

 doubtedly afford much gratification to any one who might devote 

 attention to the subject ; but nothing is more difficult than an 

 investigation of that which refers to this part of Ornithology. 

 The luxuriance of our vegetation is such that, wherever forest- 

 trees have yielded to brush-wood and its accompanying variety 

 of plants, the foliage forms a dense screen, impervious to the 

 sight, and concealing within its recess every possible object ; in 

 fact it is by mere chance that even a close scrutiny can discover 

 the fabrics which so many species repair thither to construct, and 

 dispose with such artistic skill and care. Even when they are 

 built on large trees, the foliage invariably shrouds them from the 

 eye. There are, however, a few species, such as the carouge and 

 the cassique which seem to avoid those retreats, and, in preference, 

 pend their nests to the extremity of branches, and in the full 

 glitter of the sunbeams. Many pairs of the above congregate at 

 the season of laying, and make choice of the same tree. They 

 give to their nests the shape of an elongated pear, or rather of a 

 long pouch, the smaller end hanging from the branch by means of 

 a few threads from the tissue of the nest itself. The entrance is 

 lateral, and a little beneath the point of attach the whole being 

 light and graceful, and recalling to the mind that admirable 

 instinct of the feathered tribe, which we cannot but admire in 

 such constructions. Nothing, however, equals the effect which 

 . the assemblage of those pendent nests produces ; forming as they 

 do to the tree, another sort of covering which is as agreeably 

 striking as the foliage itself. 



B B 



