The Peregrine Falcon is found throughout the Argentine Republic, but is nowhere numerous, and is not migratory; nor is it "essentially a duck-hawk," as in India according to Dr. Anderson, for, it preys chiefly on land birds. It is solitary, and each bird possesses a favourite resting-place or _home_, where it spends several hours every day, and also roosts at night. Where there are trees it has its chosen site where it may always be found at noon; but on the open treeless pampas a mound of earth or the bleached skull of a horse or cow serves it for a perch, and here for months the bird may be found every day on its stand. It sits upright and motionless, springs suddenly into the air when taking flight, and flies in a straight line, and with a velocity which few birds can equal. Its appearance always causes great consternation amongst other birds, for even the Spur-winged Lapwing, the spirited persecutor of all other Hawks, flies screaming with terror from it. It prefers attacking moderately large birds, striking them on the wing, after which it stoops to pick them up. While out riding one day, I saw a Peregrine sweep down from a great height and strike a Burrowing-Owl to the earth, the Owl having risen up before me. It then picked it up and flew away with it in its talons. The Peregrine possesses one very curious habit. When a plover, pigeon, or duck is killed, it eats the skin and flesh of the head and neck, picking the vertebræ clean of the flesh down to the breast-bone, and also eating the eyes, but leaving the body untouched. I have found scores of dead birds with head and neck picked clean in this way; and once I watched for some months a Peregrine which had established itself near my home, where it made havoc among the Pigeons; and I frequently marked the spot to which it carried its prey, and on going to the place always found that the Pigeon's head and neck only had been stripped of flesh. The Burrowing-Owl has an analogous habit, for it invariably rejects the hind quarters of the toads and frogs which it captures. At the approach of the warm season the Peregrines are often seen in twos and threes violently pursuing each other at a great height in the air, and uttering shrill piercing screams, which can be heard distinctly after the birds have disappeared from sight. 304. FALCO FUSCO-CÆRULESCENS, Vieill. (ORANGE-CHESTED HOBBY.) +Falco femoralis+, _Burm. La-Plata Reise_, ii. p. 437 (Pampas). +Hypotriorchis femoralis+, _Scl. et Salv. Nomencl._ p. 121; _iid. P. Z. S._ 1868, p. 143 (Buenos Ayres); _Hudson, P. Z. S._ 1872, p. 536 (Rio Negro); _Durnford, Ibis_, 1877, p. 187, (Buenos Ayres), et 1878, p. 398 (Patagonia); _Salvin, Ibis_, 1880, p. 362 (Salta); _Gibson, Ibis_, 1879, p. 412 (Buenos Ayres); _White, P. Z. S._ 1883, p. 41 (Cordova); _Withington, Ibis_, 1888, p. 470 (Lomas de Zamora). +Falco fusco-cærulescens+, _Sharpe, Cat. B._ p. 400.