The Pigeon Hawks 



by giddy swoops and sallies, or else took a turn around the sea-wall, 

 screaming frightfully. 



Given speed, courage, and good appetites, all of which these birds 

 undoubtedly possess, it is difficult to conceive of more Eden-like conditions 

 than those here provided for the Falcons. Sea-birds of eleven species 

 make Carroll Islet home, and it is in the highway of passage during 

 migrations. The Falcons had only to covet and kill morning, noon and 

 night. Indeed, so lavish was the provision made for them that their 

 presence did not seem to cause concern to the myriad sea-fowl. The 

 Falcon's choice appeared to fall oftenest upon the Cassin Auklets, and 

 most of the tragic feather-heaps discovered belonged to this species. Since 

 the Auklets fly only by night during the breeding season, we were forced 

 to conclude that the Falcons secured their favorite quarry after nightfall 

 or else very early in the morning. 



No. 321 



Pigeon Hawk 



A. O. U. No. 357. Falco columbarius columbarius Linnaeus. 



Description. — Old male: Above bluish gray or dark slaty blue; feathers with 

 black shafts (and sometimes pale or rusty edges); general color usually interrupted by 

 outcropping white or buffy on nape; tip of wing formed by 2nd and 3rd primaries, 1st 

 shorter than 4th, 1st and 2nd sharply notched on the inner web; the 2nd and 3rd 

 slightly emarginate on the outer web; inner webs of all quills barred or spotted with 

 whitish; tail black, narrowly white-tipped and crossed by four narrow, whitish bars 

 (slaty on middle pair), the anterior one concealed; chin, throat, and jugulum pale 

 ochraceous buff, nearly immaculate; remaining underparts tawny or ochraceous, 

 heavily streaked with dark umber, sometimes changing to bars on the flanks; sides of 

 throat and cheeks finely pencilled with umber; axillars and lining of wings dusky with 

 some admixture of tawny, and heavily marked with paired round spots of white. 

 Iris brown; bill and claws blue-black; feet yellow; cere and base of bill greenish yellow. 

 This high plumage is quite rare. Adult female and male in usual dress: Above dark 

 umber-brown, glaucous or not; the head and neck much varied, the back and scapulars 

 less varied by buffy or rusty edgings and blackish central or shaft-streaks; quill spots 

 ochraceous buff; the outer webs of primaries after second also ochraceous-spotted; 

 underparts not noticeably different from male in high plumage. Immature: Perhaps 

 lighter above and with more ochraceous buffy edging; otherwise not appreciably, or at 

 least constantly, different from adult. Adult male, length: 254-292.1 (10. 00-11. 50) ;. 

 wing 177.8 (7.00); tail 124.5 (4.90); bill 12.2 (.48). Adult female, length: 304.8-330.2 

 (12.00-13.00); wing 215.9 (8.50); tail 137.2 (5.40); bill 14.5 (.57). 



Recognition Marks. — Little hawk size; swift flight; sharp wings; stout pro- 

 163O 



