2C4 Mearns on the America// Spar/-o-v Hanjks. fj^'y 



tail, replaced bv dark plumbeous in the male, and both sexes deep rufous, 

 on the underparts. 



Sex/ial Differences. — In all plumages succeeding that of downy nest- 

 lings, the sexes are readily distinguishable. In addition to its larger 

 size, the female may be instantly recognized by the absence of plumbeous 

 on the wings. The regular transverse barring or spotting from the nape 

 to the extremity of the tail is diagnostic of the female in all but Falco 

 caribbcearit//i, in which the male is similarly banded, and F. sparveri/is 

 (pq/iatorialis, in which the rump of the female is immaculate. In all, the 

 plumage of the female is duller; and, as a rule, the markings of the under 

 parts (except in Falco caribbiEar/i/ii) are brownish instead of black, and 

 tending to longitudinal stripes rather than round spots. The female of 

 Falco spart<erins, except in the subspecies crq/iatorialis, usually lacks the 

 tawny ochraceous buft'of the underparts which distinguishes adult males. 

 The reddish crown patch is common to both sexes and all ages, though 

 often much reduced in size or entirely absent, except in specimens from 

 the interior region of North America, in which it is largely developed. 

 The feathers of the rusty crown patch are often more streaked centrally 

 with duskv or plumbeous in females than in males. 



Differences depending on Age. — The age differences in the American 

 species of this group are limited to slight modifications of the adult, a 

 marked peculiarity being the early age at which the perfect adult plu- 

 mage is acquired. All winter specimens from north of the equator are 

 practically in adult plumage, though young birds at that season are dis- 

 tinguishable by the paler yellow of the cere and feet, as well as by ana- 

 tomical conditions. I am inclined to the opinion that the oldest males, in 

 F. sparverius are those having the least number of spots on the under 

 surface, though Florida specimens show less spotting than those from 

 other regions on the continent of America (unless those from near the 

 coast in equatorial South America), thus approaching, as they sometimes 

 do in other respects, the (usually) unspotted West Indian Falco domini- 

 ccnsis. Specimens from the western United Stales, Mexico, Central and 

 Southern America, are all spotted below, though a few from Texas and 

 Arizona are slightly so. 



The series of young males of the year from east of the Mississippi 

 River comprises specimens taken in June, July, August, September and 

 October, those captured during the last month being mostly in the patchy 

 condition incident to the transition from the young to the adult plumage. 

 These young males differ from adults at the same season in having the 

 feathers edged with white or pale rusty, and the markings suffused. The 

 huffy ochraceous color of the underparts is much paler, usually cream- 

 buff, tho.ugh the intensity varies much with the individual, even in young 

 of the same brood. The spotting, which is chiefly confined to the sides 

 or flanks in old males, extends to the front of the chest, where the spots 

 have a linear instead of rounded form. In most very young birds the 

 ashy feathers of the crown and wing-coverts have rusty edges, the former 

 with narrow, dark shaft-streaks, also extending to the rusty crown patch 



