30 
U. S. P. R. R. EXP. AND SURVEYS-ROUTE TO CALIFORNIA. 
the desert between the Colorado and Oarissa creek. It here finds an ample supply of food from 
the carcasses of the numerous animals perishing from fatigue or the want of grass and water, 
and whose whitened hones, 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, o 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. 
POLYBOBUS THABUS, Molina .—The Caracara Eagle. 
Polyborus tharus, C ssin, Gen. Rep. IX, 45. 
Polyborus vulgaris, Vieili,. Gal. vol. I, p. 23; pi. 7.— Aud Birds of Ainer. Fol. pi. 161. 
Polyborus braziliensis, Aud. 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 chrysaetos, Rich, and Swain, Faun. Bor. Ainer. vol. II, p. 12. — Aud. Birds of Amer. Fol. pi. 181.—Ib. Birds 
of Amer. Oct. vol. I, p. 50 ; pi. 12. 
Aquila canadensis, Cassin, Gen. Rep. 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. 
Haliaetus leucocephalus, Aud. B. of A. Oct. vol. I, p. 57 ; pi. 14. 
Falco leucocephalus, Aud. 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, 
