LAND BIRDS. 277 



were taken between April 1st and 15th, one set April 21st, one April 18th, 

 two on May 5th, and the latest one May 13th. The nests are similar to 

 those of the^Red-tail and we know of no way in which they can be surely 

 discriminated. The eggs, however, average smaller and are more heavily 

 spotted, with a smaller proportion of entirely unspotted eggs. The usual 

 number of eggs is three, but four are often found. The ground color 

 varies from white to pale brownish and they are variously spotted and 

 splashed with brown of different shades. They average 2.13 by 1.69 inches. 

 It is difficult to discriminate between the call notes of this species and 

 the Red-tail, and still more difficult to put the distinctions into words. 

 Captain Bendire says "The note of early spring, especially in mating 

 season, is 'kee-yooh, kee-yooh,' the last syllable drawn out," and Dr. 

 Ralph says the call-note is "a loud whistle-like sound, resembling 

 'whee-ee-e,' with once in a while a 'ca-ac' added to or rather mixed with 

 it" (Bendire, Life Histories, I, 222). 



TECHNICAL DESCRIPTION. 



Four outer primaries distinctly notched (emarginate) on inner webs, the outer webs 

 spotted with white or buff. 



Adult: Upper parts mottled with reddish brown and blackish, the feathers often 

 with purplish reflections and sometimes tipped or margined with whitish; chin and throat 

 white or whitish with a few narrow dark shaft-stripes; upper breast with similar streaks 

 on a rusty ground, and more or less barred with white; lower breast, belly and sides regularly 

 cross-barred with rusty and white, with a few longitudinal streaks of dark brown; under 

 tail-coverts white and unspotted; shoulders (lesser wing-coverts) bright rust-red; tail 

 black with about four narrow white cross bars, the white tip making a fifth bar; iris reddish 

 brown. Immature: Upper parts similar, but with more numerous white edgings, the 

 shoulders duller red; under parts creamy to buffy white with numerous rounded, tear- 

 shaped or lance-shaped spots and streaks of brown, but with no trace of rusty and white 

 bars; tail pale brown (often quite rusty on outer webs of feathers near the base) with a 

 narrow white tip and about eight dark brown or blackish cross bars. 



Male: Length, 17.50 to 19.50 inches; wing, 11.25 to 13.50; tail, 8 to'9.50. Female: 

 Length, 19 to 22 inches; wing, 13.35 to 14.25; tail, 9 to 10. 



140. Swainson's Hawk. Buteo swainsoni (Bonap.). (342) 



Synonyms: Brown Hawk, Black Hawk, Hen Hawk. — Buteo swainsoni, Bonap., 1838, 

 Coues, 1866. — Falco obsoletus, Gmel., 1789. — Buteo montanus, Nutt., 1833. 



The adult in normal plumage is likely to be mistaken for the immature 

 Red-tail or possibly for the Red-shouldered Hawk, but it lacks the rufous 

 wing-coverts, and has a broad pectoral band of gray, brown, or cinnamon, 

 separating the white throat from the nearly white belly. The fact that 

 this hawk has only three primaries emarginate (cut out) on the inner webs 

 will separate it from either of the two hawks just named. 



Distribution. — Western Noi-th America from Wisconsin, Illinois, Arkansas 

 and Texas to the Pacific and south to the Argentine Republic. Casual 

 cast to Maine and Massachusetts. Breeds nearly throughout its range. 



Swainson's Hawk is a western bird which straggles eastward occasionally, 

 specimens having been taken in many of the eastern states. It has been 

 reported from Michigan a dozen times or more, but it seems probable that 

 in most cases the birds so reported have been improperly identified; at all 

 events in several instances specimens labelled and reported as Swainson's 

 Hawk have been examined and proved to be Red-shouldered or Red-tailed 

 Hawks. There are but two unquestionable records for the state, so far as 

 we now know. The first is a specimen taken by Norman A. Wood, 



