532 SYSTEMATIC SYNOPSIS. —BAPTOBHS—ACCIPITBES. 



178. FAL'CO. (L;it. faleo, a falcon or fauccm.) Characters as above, with minor modifications as 



follows : — 



Analysis of Subgenera and Species. 



Tarsus more or less featlicred above, eLsewbere irregularly reticulate in small pattern {no large plates 

 like scutelia); 2d primary longest; 1st longer tban 4tb, and decidedly emarginate on inner web. {Gyr- 

 falcons, tanners, and peregrines. ) 



Gyrfalcons : Tarsus fealbered fully ^ down in front and on sides, leaving but a narrow strip 

 bare bebind ; longer tban middle toe witbout claw ; 1st quill sborter tban 3d. Sexes alike. 

 Very large ; about 2 feet long. (Hiekofalco.) 



Prevailing color dark ; head and neck darker tban back sacer 498, 499 



Prevailing color dark ; bead and neck lighter tban back islandicus 500 



Prevailing color white candicans 601 



Lariner.^ : Tarsus feathered J w^ay down in front, broadly bare behind; longer than middle toe 

 witbout claw.; 1st quill shorter than 3d. Medium; grayish-brown above ; sexes alike. (Gen- 



NAIA.) mexicanus 502 



Peregrines: Tarsus feathered but a little way down in front, broadly bare behind; not longer 

 than ruiddle toe without claw; 1st quill not sborter tban 3d. Medium: slaty-bluish above; 



sexes alike. (Falco.) peregrinus 503, 504 



Tarsus scarcely feathered above, with the plates in front enlarged, like a double row of alternating 

 scutella (and often with a few true scuteila at base); 2d or 3d primary longest; 1st not longer than 

 4th ; 1st and 2d emarginate on inner webs. {MerVms and Kestrels.) 



Merlins: Tarsus longer than middle toe witbout claw. Sexes unlike ; young of both like adult 



female. Small; wing 7.50-8.50. (^Esalon.) columtxtrius 505,506,507 



Kestrels: Tarsus longer than middle toe without claw. Sexes very unlike at all ages. Smallest: 

 wing 7.00-7.50. (TraNCSCtrLUS.) 



Under jiarts white or tawny ; back of male and female rufous, barred or plain sparrerius ,508, 509 



Under parts rufous; back of male plumbeous, of female rufous sjinrrrrioides 510 



Hobbies: Tarsus little longer than middle toe witbout claw. Sexes alike; young little diflerent. 

 Medium; wing 10.00 or more (Khykchopalco.) fuscicfsrutescens 511 



498. p. sa'cer. (Lat. .sffcec, sacri-tl.) American Continental Gyefalcon. One of the largest 

 and most powerful of the Fiilconmce. Feet very stout ; tarsus rather longer than middle toe 

 without claw, feathered fully half-way dowTi in front and on sides, witli narrow hare strip 

 behind; elsewhere reticulate. Wing pointed by 2d quill, supported nearly to the end by the 

 3d; 1st rather shorter than 3d, only tlie 1st decidedly emarginate on inner web. Tail rounded. 

 Sexes alike. Young little different. Wing of (J 13.50-1J:.50; tail 8.50-9.50; w-ing of 9 

 15.00-16.00; tail 9.00-10.00. Adults: General plumage of the upper parts barred with dark 

 brown and pale ash, the former predominating, especially on the head and neck ; tail closely 

 barred with light and dark in about equal amounts. Lower parts white, immaculate on 

 throat, elsewhere streaked and variously spotted with dusky. Young darker than the adults ; 

 at an early stage, some of the lighter m;irkings tinged with ochraceous. Tliis is the stoek- 

 f(3rm of Continental N. Am., probably inseparable from F. gyrfalco of Europe ; the distinctious 

 from F. islandicus being moreover not very apparent. I suspect the truth to be, in respect to 

 all the gyrfalcons, that there is but a single circumpolar species ; that mtli specimens enough 

 an uninterrupted series could be esttiblished connecting the blackest " obsoletus " with the 

 whitest " candicans" ; and that the races even, which most ornithologists recognize, are not 

 coincident with geographical areas. But I defer in this case to those authorities who have 

 formed the contrary opinion, upon much furtlier investigation of the subject thtin I have 

 ever made. Gyrfalcons of the present kind, or of Nos. 499, 500, not infrequently visit the North- 

 em States in winter, sometimes even reaching the Middle States and Kansas. They reside 

 in summer beycnid the U. S., and abound in the Arctic regions, nesting in trees or cliffs, pireying 

 upon hares, grouse, ptarmigan, ducks, auks, etc. The eggs range from 3.25 to 2.50 in length, 

 X 1.60 to 1.90 in breadth, and are usually heavily colored with reddish and brownish pig- 

 ments in interminable variety. 



499. F. s. obsole'tus. (Lat. ohsoktus, unwonted.) Labrador Gtefalcon. A dark pliase of 

 the last, almost entirely dusky, the usual markings nearly obliterated ; from the foggy coast of 



