132 THE CONDOR Vol. XVI Astur. atricapillus atricapillus. Goshawk. I observed a pair of these birds June 29, 1911, in a heavy stand of spruce timber on Beaver Creek, in the Sun River country. I believe they had a nest in' the vicinity. I saw another bird on the West Fork of the Sun River September 3, 1912. Buteo borealis calurus. Western Redtail. Common summer resident. The commonest hawk in the mountains, but occurs rarely on the prairies. Nests occasionally in large firs, but much more frequently on rocky ledges on the faces of steep cliffs. Buteo swainsoni. Swainson Hawk. Common summer resident of the prairies, nesting in cottonwood groves. Also found along the base of the mountains, where it nests in the limber pines. I found one nest placed in a 'willow bush but six feet from the ground. Nesting begins late in May. Mi- gration dates: May 1, 1912, and September 27, 1911. Archibuteo lagopus sancti-johannis. Rough-legged' Hawk. I observed this hawk b.ut once: January 8, 1912. Archibuteo ferrugineus. Ferruginous Rough-leg. Summer resident; not common. A pair nest each year on the precipitous face of Priest Butte. Nest- ing begins early in May, and I was ihformed that this nest contained eggs and newly-hatched young on June 2, 1912. Aquila chrysaetos. Golden Eagle. Permanent resident. Most common along the bases of the mountains. Haliaeetus leucocephalus alascanus. Northern Bald Eagle. Rare. have seen it only in March and November, when there seems to b? a migration of this species along the foothills of the mountains. I have listed it as the sub- species alascanus on the strength of a mounted specimen in the Forest Service office at Choteau. This is a bird in juvenal plumage. It measures: wing, 27.5 inches, tail, 16.0 inches, and tarsus, 4.4 inches, measurements certainly large enough to class it with the northern subspecies. This bird came from a little outside this region, having been secured by Mr. W. H. Daugs of the For- est Service on the South Fork of the Flathead River, west of the continental divide. Falco rusticolus rusticolus. Gray Gyrfalcon. I observed a bird of this species very closely at Collins, January 8, 1912. Falco mexicanus. Prairie Falcon. Summer resident in the prairie re- gion. A pair nested on the side of Rattlesnake Butte in 1912. Falco peregrinus anatum. Duck Hawk. Rare summer resident. I saw a pair near the cliffs on Priest Butte several times in the summer of 1911, and believe that they nested there. They were not present in 1912, however. Falco sloarverius phalaena. Desert Sparrow Hawk. Summer resident in the prairie region. I found a nest in an old flicker hole in a cottonwood near Choteau, in 1912. The young from this nest were on the wing July 14. This hawk is less common here than in southern Montana. Migration dates: May 19, 1912, and September 28, 1911. Pandion haliaetus carolinensis. Osprey. Observed once, along the Teton River, near Choteau? May 19, 1912. Asio fiammeus. Short-cared Owl. Common summer resident of the prai- ries. I believe that at least four pairs nested within a radius of two miles of Choteau in 1912 (see CONDOR, XV, 1913, pp. 121-125). Bubo virginianus loallescens. Western Horned Owl. Permanent resident
