FALCO SPARVERinS. 579 



more need be said than tliat It occurs rrrn/irl/crc, in suitable places; at the 

 same time, we may remark that it is by far tlie most abundant of all the 

 Ijirds of prey, althoug-h i(s numbers vary greatly with the locality. At a 

 certain si)ot along the Carson River, not far from Carson City, stood, in 

 the spring of 1868, a clump of five large cotton-wood trees, the only ones for 

 miles around, and each of these trees was inhabited by a pair of these little 

 Falcons, who had nests in the hollows of the limbs. This is well known to 

 be the favorite location for their nests; but where there were no trees to ac- 

 commodate them, we found them adapting their nesting-habits to the char- 

 acter of the surroundings. Thus, in the precipitous canons of the Ruby 

 Mountains, tliey built among the crevices of the limestone clitiis, in com- 

 pany with the Prairie Falcon {F. poltjm/nis), the Violet-green and Cliff 

 Swallows, and the White-throated Swift ; while in some portions of Utah 

 they took possession of the holes dug by the Kingfishers and Red-shafted 

 Flickers in the earthy banks of the ravines. Among the cliffs of Echo 

 Canon, along the line of the Union Pacific Railroad, in Utah, we noticed 

 these birds in August swarming by hundreds about the brow of the preci- 

 pice, several hundred feet overhead. 



Lint of specimens. 



Co, S (1(1; Sacramento, California, June 20, 1867. lOg — 22g — 7f C| ^-— IJ 



5—4. Bill, bluisb-wbite, growing slate-black terminally; cere and angle of the mouth, 

 intense orange-red ; \v\s, very dark browu ; tarsi and toes, deep orange-chrouie ; ela\v.s, 

 jet-black. 



107, <? ad.; Big Bend of tbe Truckee (Camp 12), Nevada, July 20, 1SC7. 10— 

 223—7^— Oy— i-'g— IjL— 5§_3jJ^. Bill, pale blue basally, slate-black terminally; cero 

 and bare orbital region, pale dull yellow ; iris, vandyke-brown ; tarsi and toes, dull 

 yellow; claws, black. 



108, ? juv. (young of preceding) ; Camp 12, July 20, 18G7. lOf— 23— 7j%— 0^'^.— 

 h. — 1 — 5i — 3i. Bill, paJe fleshy blue, or Ulaccous-tchite ; cere and orbital region, pale 

 dull yellow ; iris dark brown ; tarsi and toes, very pale dull yellow. 



125, $ ad.; Camp 12, August 0, 18G7. 10|— 22^7f-6|-j%— i|-5|-3J L. Basal 

 half of the bill, pure pale blue, terminal portion slate-black; cere and bare orbital region, 

 dull yellow ; iris, very deep browu ; tarsi an<l toes, deep cLromcyellow ; claws, black. 



343, 9 ad.; near Fort Churchill, Nevada, December 0, 1S07. lli_24— 8''— 7— 

 fs — ]| — SJ — 3§. Same remarks. 



419, " 9 ad.; San Francisco, California, January 23, 1808. lli— 24i— {?)— 7^." 

 (Presented by IMr. II. G. Parker.) 



420, "9o«/.; San Francisco, January 23, 1868. llj— 237_(f)— CJ.'' (O. G. 

 Parker.) 



