BIRDS. 



II 



higher and higher, till at last, with its beak wide open, the crown almost touches 

 the lower part of the back. This fact, which has been doubted, is true ; for I have 

 myself several times seen them with their heads backwards, in a completely 

 inverted position. The Carrancha builds a large coarse nest, either in a 

 low cliff, or in a bush or lofty tree. To these observations I may add, on 

 the high authority of Azara, whose statements have lately been so fully 

 confirmed by M. D'Orbigny, that the Carrancha feeds on worms, shells, slugs, 

 grasshoppers, and frogs ; that it destroys young lambs by tearing the umbilical 

 cord : and that it pursues the Gallinazos and gulls which attend the slaughtering- 

 houses, till these birds are compelled to vomit up any carrion they may 

 have lately gorged. Lastly, Azara states that several Carranchas, five or six 

 together, will unite in chase of large birds, even such as herons. All these facts 

 show that it is a bird of very versatile habits and considerable ingenuity. 



I am led to suppose that the young birds of this species sometimes congre- 

 gate together. On the plains of Santa Cruz (lat. 50° S. in Patagonia), I saw in 

 the month of April, or early autumn, between twenty and thirty Polybori, which 

 I at first thought would form a species distinct from P. Brasiliensis. Amongst 

 those I killed, there were some of both sexes ; but the ovarium in the hens was 

 only slightly granular. The plumage of the different individuals was nearly 

 similar ; and in none appeared like that of an adult bird, although certainly 

 not of a very young one. Having mentioned these circumstances to Mr. 

 Gould, he likewise suspected it would form a new species ; but the differences 

 appear so trifling between it and the specimens of young birds in the British 

 Museum and in the Museum of the Zoological Society, and likewise of the figure 

 of a young bird given by Spix, (Avium Species Novae, vol. i. p. 3.), that I have 

 thought it advisable merely to allude to the circumstance. In my specimen, 

 which is a cock, the head, instead of being of a dark brown, which is the usual 

 character of even very immature birds, is of a pale rusty brown. The bill and 

 cere are less produced than in the adult P. Brasiliensis ; and the cere is of a 

 brighter colour, than what appears to be usual in the young of this species. In 

 other respects there is such a perfect similarity between them, that I do not 

 hesitate to consider my specimen as a young bird of the P. Brasiliensis in one 

 of its states of change ; — and to be subject to great variation of plumage during 

 growth, is known to be a character common to the birds of this sub-family. It 

 may, however, possibly be some variety of the P. Brasiliensis, for this bird seems 

 subject to variation : Azara (Voyage dans l'Amerique Meridionale, vol. iii. p. 35.) 

 remarks, " II y a des individus dont les teintes sont plus faibles, ou d'un brun 

 pale, avec des taches sur la poitrine, et d'autres qui ont des couleurs plus foncees ; 

 j'ai decrit ceux qui tiennent le milieu entre les uns et les autres." 



I have myself more than once observed a single very pale-coloured bird, in 



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