650 BULLETIN 50, UNITED STATES NATIONAL MUSEUM 



FALCO PEREGRINUS ANATUM Bonaparie 



Duck Hawk 



Adult male. — Forehead dirtj- warm buff; crown, occiput, nape, 

 and anterior interscapulars deep neutral gray to dark neutral gray to 

 blackish plumbeous; the bases of the feathers of the nape whitish 

 or pale buffy, occasionally slightly visible; the interscapulars tipped 

 and crossed by a single band of slate gray; posterior interscapulars, 

 scapulars, back, rump, and upper tail coverts gull gray to deep gull 

 gray, generally palest on the rump and upper tail coverts, and each 

 feather with narrow blackish slate shafts and crossed by three or four 

 fairly broad blackish slate bars; upper wing coverts slate narrowly 



Figure 47. — Falco (Rhynchodoti) pcregrinus. 



tipped with gull gray to pale gull gray, the greater coverts obscurely 

 banded with slate gray; primaries slate black externally and ter- 

 minally (for about one-fourth to one-third their length), the inner 

 webs whitish to gull gray on their basal two-thirds to three-quarters, 

 barred with slate blacls: (about twelve to thirteen such bars on the 

 outermost primaries; fewer on the more inner ones; the primaries 

 (in fresh plumage) very narrowly tipped with whitish; secondaries slate 

 gray to dark dull gray, paling to white on the inner webs, and barred 

 (somev/hat obscurely on the darker, outer webs) with dark slate; 

 next to the outermost primary the longest, then the outennost, then 

 the thu'd from the outside, the outermost one abruptly indented on the 

 inner web about 40-50 mm. from the tip; rectrices light neutral gray 

 to slate gray, tipped with dirty whitish; paling on the inner margin 

 of the inner webs of the lateral feathers to dirty whitish, and crossed 

 by eleven or twelve bars of blackish slate, the bars narrow toward 



