THE AMERICAN GOSHAWK. 161 



Distribution. — Abroad. — Europe generally, and north-west Africa, . 

 but replaced by allied races in various parts of northern Asia, 

 Sardinia, and North America. 



261. Accipiter gentilis atricapillus (Wilson) — THE AMERI- 

 CAN GOSHAWK. 



Falco atricapillus Wilson, Amer. Orn., vi, p. 80, pi. 52, fig. 3 



(181 2— Philadelphia) . 



Accipiter gentilis atricapillus W. J. Williams, Brit. B , xni, p. 31. 



Description. — Adult male and female. Winter and summer.- — ■ 

 Differ from A. g. gentilis in crown being slate-black ; rest of upper- 

 parts dark slate tinged brown (purer slate when freshly moulted) 

 feathers with blackish shafts and except when worn with very 

 narrow blackish edgings ; hind-part of ear-coverts blackish ; under- 

 parts not white barred black-brown, but each feather closely 

 mottled or irregularly barred brown-grey on whitish ground and 

 varying number with prominent black shaft-streak varying in 

 width and most prominent on throat and breast, brown-grey mark- 

 ings more definitely in form of bars in some examples than in others 

 and most prominent on tibia and flanks ; under wing-coverts white 

 barred blackish ; under tail-coverts white with varying amount 

 of brown-grey barring and often slight mottling ; central tail- 

 feathers and outer webs of rest and outer webs of wing-feathers 

 more slate-grey than in A. g. gentilis ; wing-coverts as rest of upper- 

 parts. Females are usually paler grey on upper-parts than males. 

 No moulting examples examined. 



Nestling . — (Not examined . ) 



Juvenile. — Like that of A. g. gentilis. 



First winter and summer. — As juvenile. 



Second winter. — Juvenile plumage appears to be completely 

 moulted in second autumn as in A. g. gentilis. Bird then becomes 

 as adult but feathers of breast have broad brownish shaft-stripes 

 and some broad barring varying individually but distinguishing 

 from adult ; some juvenile feathers usually retained on rump and 

 occasionally on lesser wing-coverts ; feathers of fore-part of crown 

 usually with buffish edgings. 



Measurements and structure. — (J wing 320-345 mm., tail 220- 

 250, tarsus 73-80, bill from cere 21-23 (10 measured). $ wing 355- 

 370. Primaries : 1st equals 9th, between 8th and 9th or shorter 

 than 9th, 4th longest, 5th 3-8 mm. shorter (rarely equals 4th), 

 3rd 5-12 shorter, 2nd 30-45 shorter, 6th 20-40 shorter ; 3rd to 6th 

 emarginated on outer and 1st to 5th on inner webs. 



Breeding-habits. — Haunts well-wooded districts, breeding in 

 both conifers and hardwoods. Nest. — Bulky, built of sticks with 

 shallow cup lined with a few green twigs, feathers and bark. Eggs. 

 — Varying from 2 to 5, but most frequently 3-4 ; bluish-white 

 in colour, rather rough and coarse in grain. Average of 30 eggs, 



VOL. II. m 



