THE NIDIOLOGIST. 



The Breeding Habits of Audubon's 

 Caracara. 



ArnUBOX'vS Caracara, known by the 

 Texans as the Mexican Eagle and I)}- 

 the Mexicans as 'fotac/ie, is one of the 

 most common raptorial birds in man\' sec- 

 tions of Central and Southern Texas. On 

 the Rio Grande and along the Gulf Coast it 

 is especiall\^ abundant, associating with 

 Harris' Hawk and the Vultures. In the 

 two counties of the central portion of the 

 State (Falls and McLennan) in which I 

 have observed this species, I consider it a 

 tolerably common resident, doubtless oc- 

 curring in all seasons, as I have noted indi- 

 viduals in each month. About the first of 

 March the birds pair and commence repair- 

 ing old or selecting new nesting sites, and 

 by the first week in April nidification is at 

 its height. A correspondent in Bexar 

 county informs me that in his section he 

 finds nests of the Caracara from early March 

 to the last of May, and all recorded sets 

 from this locality were taken between 

 March 20 and May 25. Their nests are 

 usually built in a low bushy tree at a height 

 of from eight to twenty feet from the 

 ground, and are used by the .same pair of 

 birds each consecutive year, even after they 

 have been robbed of their eggs. New 

 material is added each season, and the nest 

 gradually assumes enormous proportions. 

 From seemingly reliable authoritjs I have 

 been informed of ne.sts which had been used 

 for years and which had finally grown to be 

 about four feet in diameter by two in depth. 

 The composition of the.se nests .seems to 

 vary with the locality in which they are 

 built. Dr. Brewer states that nests report- 

 ed from Northern Mexico and the Lower 

 Rio Grande Valley of Texas were composed 

 of flags, reeds and grass, were very coarse 

 and flat, and were usually situated on the 

 tops of trees or on low cliffs, or even 

 bushes. In this section the composition is 

 usually branches and large twigs, some- 

 times lined with roots and grasses. 



One nest I examined this last April was 

 composed entirely of thick broomweed 

 without any lining whatever, and had only 

 a very slight depression for the eggs, hard- 

 ly sufficient to keep them from rolling out, 

 in fact. The diameter of this ne.st was 

 about twenty-two inches. On April i a 

 typical .set of two eggs were taken from it, 

 and they present the following measure- 

 ments in inches: 2.51 x 1.63 and 2.70 x 

 1.69. Their ground color is the same, i. e., 

 a dark russet-brown, but in markings they 

 differ greatly. One &gg is almost entirely 

 unspotted with the exception of half a dozen 

 minute chocolate flecks and two or three 

 chalky spots about the size ofapinhead, 

 while the other is beautifully mottled with 

 chocolate and umber, .so thick as almost to 

 obscure the ground color. Another .set of 

 the same number taken a few^ days later are 

 marked in exactly the same manner, and, 

 in fact, all of the specimens of the eggs of 

 this bird I have seen, that have been taken 

 in this locality, vary but little as to sets. 

 Several authorities mention eggs of the 

 Caracara, with an almost pure white 

 ground, but I have never seen any answer- 

 ing that description. The number of eggs 

 laid is two or three, sets of two being the 

 most common. 



I am told that the young Caracaras oc- 

 cupy the nest for two or three months after 

 they are hatched, which, if so, shows a re- 

 semblance to the habit!? of the young of the 

 Vultures while in the nest. However, al- 

 though the young Vultures are fed by re- 

 gurgitation, the young of the Caracara are 

 fed in the same manner as other Falcons, 

 /'. e., with fresh meat, although I think that 

 the adults feed quite freely on carrion. 



In the vicinity of old nests are usually to 

 be found the skulls and bits ofthe feet, etc., 

 of small mammals, principally rodents. 

 Among these I have identified the skulls 

 of at least two species of rabbits, principal- 

 ly those of the Cottontail {Lepiis syloaticus) , 

 although some remains resemble those of 

 our larger species {L. vielaiiotis). In its 

 manner of flying the Caracara resembles 

 both the Vultures and Hawks, circling, 

 sailing and flapping alternatel3^ 



J. K. Stkhckkr, Jr. 

 Waco, Texas. 



