The Western Red-tailed Hawk 



breast, which is nearly immaculate. Immature birds frequently show strong melanistic 

 tendency, in which case the spotting of the underparts invades the breast and increases 

 elsewhere nearly to the point of confluence. Length of male (average of six adults 

 and full-grown immatures): 558.8-628.7 (22.00-24.75); wing 402.6 (15.85); tail 241.3 

 (9.50); chord of culmen 25.2 (.99); tarsus 91.6 (3.61). Length of female (6 adults and 

 near adults): 590.6-692.2 (23.25-27.25); wing 425.5 (16.75); tail 254 (10.00); bill 27 

 (1.06); tarsus 94 (3.70). 



Recognition Marks. — Crow to brant size; red tail when visible always distinc- 

 tive; stouter proportions and more regal bearing, as compared with B. swainsoni, but 

 not always distinguishable from that species afield. 



Nesting. — Nest: Of sticks, lined with bark-strips, usnea, or grass pulled up 

 by the roots; placed in crannies or ledges of cliff or high in trees. A large tree nest in 

 the M. C. O. coll. measures 3 feet long by 2 broad and 1 deep, and has a hollow 8 x 10 x 2 

 inches. Eggs: 2 or 3, rarely 4, 5 of record; white, or pale bluish white, lightly stained, 

 spotted, blotched, or smeared with reddish brown or, rarely, immaculate. The pig- 

 ment variations include tilleul buff, vinaceous buff, avellaneous, wood-brown, fawn- 

 color, Rood's brown, vandyke brown, chestnut-brown, tawny olive, and dresden 

 brown. Av. of 36 sets 59.9 x 46.2 (2.36 x 1.82); index 77. Extremes: 54-66.8 x 43.3- 

 49.5 (2.12-2.63 by 1. 70-1. 95). Season: Feb. I5th-May 1st, according to latitude 

 and altitude; one brood. 



Range of Buteo borealis. — North America, breeds from central Yukon, central 

 western Mackenzie, central Keewatin, and Newfoundland, south to Florida and the 

 Greater Antilles, Guatemala, and Cape San Lucas. 



Range of B. b. calurus. — Western North America, except the coast district of 

 southeastern Alaska, from. central Yukon and western Mackenzie south to Cape San 

 Lucas and central America; east to the western borders of the Great Plains and casually 

 to Ontario. 



Distribution in California. — Common resident of the widest distribution. 

 Breeds from Lower Sonoran deserts to the limits of Upper Transition, and wanders 

 into high Boreal. 



Authorities. — Gambel {Buteo borealis), Proc. Acad. Nat. Sci. Phila., vol. iii., 

 1846, p. 45 (upper Calif.); Coues, Birds of the Northwest, 1874, p. 352 (syn., desc, 

 crit.); Tyler, Pac. Coast Avifauna, no. 9, 1913, p. 41 (San Joaquin Valley); Wetmore, 

 Condor, vol. xviii., 1916, p. 112 (speed of flight). 



THE ALABAMA HILLS, in Inyo County, are reputed to be the 

 oldest geological formation in America. By this I suppose it is meant 

 that this modest escarpment of granite represents the core of a conti- 

 nental ridge older than the towering Sierras, which now dwarf them 

 into insignificance. The superficial details might be as recent as those 

 of any other granitic exposure; yet to the eye it is not so. It is rather as 

 though the authentic eld had been preserved intact. When one gazes 

 from above into the upper reaches of a certain canyon near Lone Pine, 

 the conviction is forced upon him that he beholds not the effects of wind 

 and weather, but those of wave erosion. These rounded and deeply 

 sculptured forms were left by the laving of a primordial sea, and they have 

 gone practically unmodified ever since. The panorama at the head of the 



