Ferruginous Hawk (Buteo regalis) 



Distribution: Breeds from eastern Washington, southern Alberta and Saskatchewan, and western 

 North Dakota south to northern Arizona and New Mexico. Locally common in Montana 

 (Bergeron et al. 1992) and western South Dakota (S.D. Omithol. Union 1991). Winters from 

 Nevada, Colorado, and Kansas south to northern Mexico. 



Habitat Use: This is a hawk adapted primarily to semiarid grasslands with scattered trees and 

 outcrops in the Great Plains. Less tolerant of agriculture than Swainson's Hawk (Schmutz 

 1984, 1987). Frequently seen in open terrain hunting for jackrabbits and ground squirrels 

 (Gilmer and Stewart 1983, Schmutz and Hungle 1989, Smith et al. 1981, Woffmden and 

 Murphy 1977); density of nesting pairs correlated with ground squirrel or jackrabbit 

 abundance (Schmutz and Hungle 1989, Smith et al. 1981) in Alberta, Canada and Utah, 

 respectively. Major foods in Carter County, Montana were Northern Pocket Gophers 

 {Thomomys talpoides) and White-tailed Jackrabbits (Lepus townsendii) (Wittenhagen 1992). 



Nest Sites: Uses the widest variety of nest sites of any of the raptors (Call 1978), including trees, 

 buttes and cliffs, chimneys, windmills, hay stacks, power poles, abandoned buildings, large 

 sagebrush, and sheepherder monuments. Of 45 nests in westem North Dakota, 21 were on 

 powerline towers, 15 on haystacks, 5 on the ground, and 4 in trees (Gilmer and Wiehe 1977); 

 in another study in southcentral North Dakota 123 nests were in trees, 39 on the ground, 7 on 

 haystacks, and 31 on powerline towers (Gilmer and Stewart 1983); for 27 nests in northern 

 South Dakota, 12 were on the ground, 13 in trees and 2 on haystacks (Lokemoen and 

 Duebbert 1976); of 29 nests in southeastern Washington 18 were on cliffs, 1 on a man-made 

 structure, and 10 in trees. South of Ekalaka in Carter County, Montana, most of 26 nests (2 

 years in a study area of 463 km^) were on the ground (Wittenhagen 1992). Over 70% of 24 

 nests in southcentral Montana were in willows (Restani 1991). Nest height is quite variable; 

 29 nests in southeastern Washington ranged from 2-56 m above the ground. This hawk will 

 use artificial nest platforms (Schmutz et al. 1984). Nests are bulkier than Swainson's Hawk 

 nests but can be confiised with Red-tailed Hawk {Buteo jamaicensis) nests when in trees 

 (Call 1978). 



Nest Success: Usually lays 2-3 eggs. Young fledged/successful nest in Carter County, Montana 

 in 4 years was 1.1 and 1.7 in 1981-82 (Ensign 1983), and 1.8 and 2.5 in 1990-91 

 (Wittenhagen 1992); nest success was 25-27% in the eariy 1980's and 75-93% in the early 

 1990's. Fledglings/active nest in 1987-88 was 2.2 in southcentral Montana (Restani 1991), 

 2.6 in southern Alberta in 1 975-77 (Schmutz et al. 1980), and 2.0-2.5 in southcentral North 

 Dakota in 1 977-79 (Gilmer and Stewart 1 983). 



Breeding Phenology: In the Sioux District area (southeastern Montana and northwestern South 

 Dakota), adults arrive in mid to late March, eggs are laid in mid-late April, hatching occurs 

 between mid-May and early June, and young fledge in late June through mid- July (Becker 

 1978, Wittenhagen 1992). 



Status: Breeds locally in the region. Numbers are up significantly in Montana, but only slightly 

 in North Dakota (Dobkin 1994); trends variable throughout the entire West (White 1994), 

 with large increases in the northern prairie provinces of Alberta and Manitoba. Olendorff 

 (1993) indicated stable populations in Montana, South Dakota, and North Dakota, with a 

 large increase in Wyoming. As with Swainson's Hawk, most (all?) pairs of this species 



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