S72 ALT)UBO^"'S CAEACAEA — P. THARUS VAR. AUDUEONI. 



was covered with Turkey Buzzards, and one specimen of the Caracara 

 Eagle was among them fbnt it proved so shy that I could not shoot it, 

 although waiting in ambush fully two hours in hopes it would return. 

 We followed this species on our survey down the Gila until we left that 

 river, seeing one or more every day, and found it again in Texas on 

 tetriking the settlements. At San Antonio, in the vicinity of slaughter- 

 houses, it is met with in great numbers, twenty or thirty often being 

 seen at one time. We found its nest on the Medina Eiver, built in an 

 oak, of coarse twigs, and lined with leaves and roots; beiug recently 

 finished, it contained no eggs." 



This statement in respect of the nidification of the Caracara is 

 confirmed by other naturalists, though it may not hold good in every 

 instance. We should rather have anticipated that it would have been 

 found to breed on rocks, fallen logs, the ground, &e., after the'fashion 

 of Vultures. According to the distinguished naturalist, Mr. Charles 

 Darwin, the South American bird occasionally breeds on a low clifi", or 

 on a bush, thus evincing its vulturine alfinities; and it is not to be pre- 

 sumed that there is any striking and constant diiference in this regard 

 between the United States and the more tropical forms of the Caracara. 

 The situation of the nest doubtless varies with circumstances ; thus, I 

 have seen a memorandum from ilr. Xantus, stating that a nest he found 

 at Cape Saint Lucas was placed on the top of a giant cactus. But 

 wherever situated, the nests, like those of most Eaptores, is a rude struc- 

 ture, compared with the elaborately planned and elegantly finished 

 structures of many higher birds, being little more than a slightly hol- 

 lowed platform of small sticks and twigs, lined with somewhat softer 

 material, as dried rushes, grasses, and leaves. 



It is possible, though improbable, that oology may eventually throw 

 more light upon the supposed distinctions between the two forms of 

 the Caracara. So Dr. Brewer intimates, iu an article prepared before 

 3Ir. Cassin established P. auduboni. " Mr. Cassin informs me," he coa- 

 tinues, " that his suspicions have been excited by certain variations in 

 specimens that have fallen under his notice, and Mr. Darwin states that 

 he met with individuals on the plains of Santa Cruz, which he and Mr. 

 Gould were almost persuaded to be distinct species. In partial con- 

 firmation of this suspicion, I may in this connection refer to the great 

 variations noticeable in the eggs of the Vulturine Eagle. These are 

 neither slight nor occasional, but are constant and of so radical a char- 

 acter as to excite the strongest doubts of their belonging to birds of the 

 same species, the differences afiecting.both their size and their ground- 

 color. The eggs from Cuba, so far as I am aware, represent one variety 

 exclusively, those from Brazil the other, while on the other hand, both 

 varieties were obtained on the Eio Grande by Dr. Berlandier, who 

 assigns them to a single species, which, in his manuscript notes, he called 

 Totaclie." The Brazilian specimens referred to were of course of the 

 true " Carrancha,'" as P. tliarus is called in South America ; the Cuban 

 ones were probably those of P. auduboni ; and the fact that both sorts 

 were got in Mexico may serve in investigating the limits of the two 

 birds. 



In examining a large number of eggs from different localities, I found 

 differences in size, shape, and color, to be fairly called remarkable, but 

 still not uuparalleled, I think, by those known to occur in other cases 

 of unquestionably the same species of rapacious birds ; nor did I recog- 

 nize any division of the series into two distinct sets. I think it would 

 be easy to lay them all in a row in such manner that extremes in any 

 respect should be connected by intermediate examples. In studying 



