192 Birds of Colorado 



beyond a few weed stems ; he found the eggs, four to 

 six in number, arranged in two rows with a space between, 

 and believed the bird rests on the soUd floor and covered 

 the two rows underneath her wings. The same site 

 is frequently used, year after year. One brood seems 

 usual, though if robbed, a second or third set of eggs 

 may be deposited. Both birds incubate. Gale found 

 fresh eggs from May 12th to June lOtb, while Dille gives 

 May 1st as an average date. A set of five eggs, taken 

 by I. C. Hall, May 20th, 1902, at Greeley, and pre- 

 sented by him to the Colorado College Museum, are 

 whitish ovals, suffused and thickly dotted and blotched 

 with dark rufous. They average 1*38 x 1*15, but there 

 is much variation in shape and markings. 



Desert Sparrow- Hawk. Falco sfarverius phcdaena. 



A.O.U. Checklist no 360a— Colorado Records— Cooke 97, p. 205 

 {F. s. deserticoliis) ; Rockwell 08, p. 163 ; Warren 09, p. 14. Some 

 of the records under F. sparverius may refer to this subspecies. 



Description. — Very close to F. sparverius but larger, and with a 

 relatively longer tail and paler rufous coloration. In the female 

 the streaks are more numerous and more yellow below ; the bars on the 

 upper-surface are narrower, and those of the tail often incomplete. 



Distribution. — This subsj>ecies, which seems to be hardly distinguish- 

 able from the typical form, is found throughout western North America, 

 from British Columbia to Guatemala and east to the Rocky Mountains. 



Cooke found that some of the Sparrow-Hawks in the Carter collection 

 obtained in the Middle and South Parks, were more nearly allied to 

 this subspecies, and probably all the birds taken on the westerr slope 

 should be so referred, if the distinction between the two forms can be 

 maintained. I have examined a male taken near Yampa in Routt co., 

 and a female from Sulphur Springs, both in the Warren collection, 

 and cannot certainly distinguish them from those taken in El Paso co. 



Family PANDIONID^. 

 Feathers without after-shafts ; outer toe reversible. 



Genus PANDION. 

 Bill strongly hooked, but without any tooth or notch on the edge of 

 the upper mandible ; nostrils oval and oblique ; wings very long and 



