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 solid 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 10th, while Dille gives 
May Ist 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 sparverius phalena. 
A.O.U. Checklist no 360a—Colorado Records—Cooke 97, p. 205 
(PF. «s. deserticolus); 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 subspecies, 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-A. 
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 
