n form, of which Krider's hawk is the eastern
analogue; the ranges of the two forms overlap on the Colorado plains;
_calurus_ breeds from plains to 12,000 feet; not a few winter in the
State.

337d. =Harlan's hawk.= BUTEO BOREALIS HARLANI. Rare winter visitor; one
specimen; natural habitat, Gulf States and lower Mississippi Valley.

339b. =Red-bellied hawk.= BUTEO LINEATUS ELEGANS. Rare migrant; Pacific
coast species.

342. =Swainson's hawk.= BUTEO SWAINSONI. Common resident; breeds
everywhere below 11,000 feet.

347a. =American rough-legged hawk.= ARCHIBUTEO LAGOPUS SANCTI-JOHANNIS.
Somewhat common winter resident; arrives from the north in November and
remains till March.

348. =Ferruginous rough-leg.= ARCHIBUTEO FERRUGINEUS. Rather common
resident; breeds on plains and in mountains; winters mostly on plains
and along lower streams.

349. =Golden eagle.= AQUILA CHRYSAETOS. Resident; common in favorable
localities; breeds from foothills to 12,500 feet; in winter on plains
and also in mountains, often at 11,000 feet.

352. =Bald eagle.= HALLAEETUS LEUCOCEPHALUS. Fairly common resident;
mostly in mountains in summer; on plains in winter.

355. =Prairie falcon.= FALCO MEXICANUS. Not uncommon resident; breeds
from plains to 10,000 feet; quite numerous in more open portions of
western Colorado.

356. =Duck hawk.= FALCO PEREGRINUS ANATUM. Resident; not uncommon
locally; breeds up to 10,000 feet.

357. =Pigeon hawk.= FALCO COLUMBARIUS. Summer resident; not common;
usual breeding grounds 8,000 to 9,000 feet; some breed on the plains.

358. =Richardson's merlin.= FALCO RICHARDSONII. Rare summer resident;
not uncommon in migration; naturalists not quite sure that it breeds in
the State; has been taken in summer at an altitude of 11,000 feet.

360. =American sparrow hawk.= FALCO SPARVERIUS. Abundant resident; the
most common hawk from the plains to 11,000 feet; some winter in State;
breeds throughout its range.

360a. =Desert sparrow hawk.= FALCO SPARVERIUS DESERTICOLUS. Resident,
though rare; taken in Middle and South Parks.

364. =American osprey.= PANDION HALIAETUS CAROLINENSIS. Summer resident;
not uncommon locally; breeds as high as 9,000 feet; has been taken in
fall at an altitude of 10,500 feet.

365. =American barn owl.= STRIX PRATINCOLA. Resident; quite rare; a
southern species rarely coming so far north as Colorado.

366. =American long-eared owl.= ASIO WILSONIANUS. Common resident;
winters from pla