30 U. S. p. B. R. EXP. AND SURVEYS — ROUTE TO CALIFORNIA. 



the desert between the Colorado and Carissa creek. It here finds an ample supply of food from 

 the carcasses of the numerous animals perishing from iatigue or the want of grass and water, 

 and whose whitened bones, strewn over the ground, mark both the road and the hardships of 

 the western pioneer. They seem to be on terms of amity with both the raven and California 

 vulture whilst feeding, but upon the approach of the coyote or prairie wolf they all retire to a 

 respectful distance until he has gorged himself on the dainty fare. The eyes of a carcass first 

 extracted, they invariably begin their assault at the anus, this being the most practicable place 

 to effectuate a breach, whence to deal havoc on the internal parts. An entrance once made, a 

 scene of plunder, noise, confusion, and dispute ensues, baffling all description. Each one 

 striving, as best he may, to bolt the morsel he has seized, or to rob his neighbor glutton, whose 

 booty is too voluminous for him to despatch at once. "When, however, in very large numbers, 

 they will attack a carcass indiscriminately at several points, wrenching off the skin and flesh 

 •with their powerful beaks, whilst they brace themselves with their feet as they pull. 



POLYBORUS THARUS, Molina.— The Caracara Eagle. 



PolyboTus tharus, C ssis, Gen. Rep. IX, 45. 



Polyborus vulgaris, Vieill. Gal. vol. I, p. 23; pi. 7. — Aud Birds of Amer. Fol. pi. 161. 



Polyborus hraziliensis, AoD. Oct. vol. I, p. 21 ; pi. 4 



I am happy to be able to add this interesting species to the fauna of California, having seen 

 it on the Colorado river, near Fort Yuma, in company with the preceding species. The carrion 

 of an ox was covered with turkey buzzards, and one specimen of the Caracara eagle was amongst 

 them, but proved so shy that I could not shoot it, although waiting in ambush full 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 striking the settlements. 

 At San Antonio, in the vicinity of slaughter-houses, it is met with in great numbers, twenty or 

 thirty often having been seen at one time. We found its nest on the Medina river, built in an 

 oak, and constructed of coarse twigs and lined with leaves and roots, but being quite recently 

 finished contained no eggs. Although so closely allied to the vulture by its habits, we find its 

 nidification quite different ; as all the birds of that family, without exception, so far as known, 

 lay either on the rocks or on the ground. 



AQUILA CANADENSIS, Linn .—The Golden Eagle. 



Aquila rhrysaetos, Rich, and Swain, Faun. Eor. Amer. Vdl. II, p. 12. — Aun. Birds of Auier. Fol. pi. 181. — Ib. Birds 



of Amer. Oct. vol. I, p. 5(1 ; pi. 12. 

 Aquila canadensis, Casbin, Gen. Rop. IX, 41. 



A specimen of this bird was seen whilst we were crossing over Livermore's Pass. It flew from 

 a rock not twenty yards distant, thereby rendering it impossible to mistake the species. I also 

 met with two others in northern California, and obtained the tarsae and feet of a specimen killed 

 in the mountains bordering the Mokelumne river. It is there, as elsewhere, a wild and scarce 

 bird, rarely seen save by the naturalist who is on the alert. 



HALIAETUS LEUCOCEPHALUS, Linn .—The Bald Eagle. 



Haliaeltts leucocephalus, Auo. B. of A. Oct. vol. I, p. 57 ; pi. 14. 

 Falco leuoocephalas, Auu. B. of A. Fol. pi. 31 and 126. 



Common in northern California, and more especially so about the falls of the Columbia river, 

 (Oregon,) the salmon of which, thrown up dead on the shores at certain periods of the year. 



