ORNITHOLOGIST 



— AND- 



OOLOGIST. 



$1.00 per 

 Annum. 



PUBLISHED BY FRANK B. WEBSTER. 



Established, March, 1875. 



Vol. XIV. 



BOSTON, MASS., MAY, 1889. 



Single Copy 

 10 cents. 



No. q. 



A List of the Birds of Colorado. 



[All Rights Reserved.] 



116. Ilalkeetus leucocephalus (Linn.). Bald 

 Eagle. Resident. Breeds in the mountainous 

 portions of the state, and is tolerably common; 

 most abundant on the plains in winter; nests in 

 trees and on ledges of cliffs. Eggs, two to 

 "four," dull white and unmarked. Tarsi 

 naked in this species but feathered to the toes 

 in A. chryfKetos, a character which will dis- 

 tinguish the two species in any plumage. The 

 perfect plumage is not obtained until the third 

 year, hence the large number of local names 

 given this species. Reaches 12,000 feet in 

 spring and summer, retires to lower altitudes 

 in the fall and remains through the winter. 



117. Falco mexicanus (Schleg.). Prairie 

 Falcon. Transient visitant; rare. Observed 

 by Drew and Anthony, also by Allen and 

 Brewster.* Breeds as high as 10,000 feet, and 

 down to the plains. In winter this species re- 

 tires to low altitudes, but the bulk migrate 

 into New Mexico from Western Colorado. 

 Nests on shelves of the rocky wash-outs of the 

 prairies, and 1 have strong suspicions that it 

 breeds at times in holes in the ground as well 

 as in hollows of trees. Have not as yet found 

 its eggs, but they are said to be "grayish- 

 white, spotted and blotched with various 

 shades of reddish-brown running together so 

 as to obscure the ground color," but this, I am 

 told, is the exception, as more often the spots 

 and blotches are collected about the larger 

 half of the egg, leaving the ground color dis- 

 tinct. They are about 2.08 x 1.70. 



118. Falco peregrinvs anatum (Bonap.). 

 Duck Hawk. Transient visitant; tolerably 

 common. Reported by Drew and Anthony. 

 Reaches 10,000 feet. A more thorough inves- 

 tigation will no doubt prove this species to be 

 a resident. Nests on shelves of cliffs and in 



* B. N. O. O., Vol. VIII, Ni>. 4, p. 

 "A few pair seen." 



197. October, 1883. 



cavities of decayed trees. Eggs, three or four, 

 of "reddish-ochre, spotted and blotched with 

 reddish and dark chocolate brown, thickest at 

 large end." 



119. Falco coliimbarius (Linn.). Pigeon 

 Hawk. Transient visitant; tolerably common 

 (Anthony), also observed by Drew. I have 

 one set of its eggs taken near Ft. Lewis, on 

 June .3, 1887. The nest was of small twigs, 

 rather loosely put together, and lined sparingly 

 with dead grass and several feathers. The 

 number of eggs were Jive, the ground color 

 being white with just a slight pinkish tint, 

 this faded after blowing to chalky white, 

 sprinkled with fine dots of drab, about evenly 

 over the entire egg in three specimens, the 

 other two having the spots congregated near 

 the large end, showing signs of a wreath, but 

 not so thickly but that all were separate and 

 distinct. The nest was but eight feet from 

 the ground in a heavy clump of alders. The 

 eggs of this set average 1.60 x 1.30. 



120. Falco richardsonii (Ridgw.). Richard- 

 son's Merlin. Reported from Eastern Colorado 

 by Capt, Thorne. Its vertical range is given 

 by Drew at from 6,000 feet in spring up to 

 11,000 feet in summer.* Allen and Brewster 

 also met w4th it. I have received no record of 

 its breeding, but I think its nest and eggs will 

 be found in the heavy vegetation fringing the 

 mountain streams. 



121. Falco sparverius (Linn.), American 

 Sparrow Hawk. Summer visitant; common. 

 Breeds abundantly in hollows of trees and old 

 Flickers' holes; in the last case it generally 

 uses no lining but the chips left by the former 

 occupant, but sometimes it improves upon this 

 primitive mode by adding a scanty lining of 

 leaves, feathers or grasses. It also deposits 

 its eggs in holes in cliffs. The eggs of this 

 species vary greatly in markings and a large 

 series is necessary to show all the the varia- 



* B. N. O. C, Vol VIII, No. 4, Oct. 1883, p. 197. 



Copyright, 1889, by Frank B. Webster. 



