THE GENUS CHORDEILES SWAINSON OBERHOLSER. 27 



Adult female. — The female differs from the male in being of some- 

 what smaller size; in having the white wing-patch smaller and 

 usually more or less mottled with dusky ; the white subterminal tail- 

 bar almost always absent, but if present much narrower; the light 

 throat-crescent cream buff to tawny ochraceous, and often more or 

 less spotted with dusky; lower parts usually more brownish, and pos- 

 teriorly averaging much more buffy or ochraceous, the crissum rarely 

 if ever pure white. Some of these sexual differences are, however, not 

 so strongly marked in certain of the. subspecies as in others. 



First autumn plumage. — Although there is some difference in the 

 various races of the species, the first autumn plumage is more or less 

 intermediate between the juvenal and adult plumages. The male in 

 first autumn plumage exhibits the following differences from the 

 adult male: Upper parts with much more numerous pale mottlings, 

 and thus lighter; white speculum smaller; primaries more or less 

 broadly tipped with whitish or buffy ; tail without subterminal white 

 band; jugulum and upper breast much vermiculated with whitish, 

 grayish or dull buffy; white throat-patch smaller, less well-defined, 

 somewhat creamy or buff}'^, and much mottled, usually all over, with 

 dusky. The feTnale in first autumn plumage is similar to the adult 

 of the same sex, but has the upper parts much more mottled with 

 lighter; the upper breast and jugulum more vermiculated with paler; 

 the buff throat-patch much more heavily marked with dusky, some- 

 times almost obliterated. In this condition the female is much like 

 the male of the first autumn, but the throat is usually more deeply 

 buff and more heavily spotted with dusky. 



Juvenal plumage. — In this stage, which immediately precedes the 

 first autumn plumage and succeeds the natal or nestling plumage, 

 and which the bird wears for apparently only a short period, both 

 male and female are usually much lighter above than in the adult 

 plumage or that of the first autumn, the ground color being paler 

 and the light mottlings prevailing; the lower surface has its dark 

 areas also paler, the barring on breast more vermiculate and nar- 

 rower; the bars on the rest of the lower surface lighter and less dis- 

 tinct; the throat-patch not very strongly indicated, and buff or 

 ochraceous buff. 



Natal plumage. — Upper parts grayish or buffy white, everywhere 

 with coarse mouse gray, drab gray, or clove brown mottling ; or fawn 

 color with Front's brown markings; below, white or cream white, 

 mottled on throat and jugulum with gray or grayish brown; or pale 

 fawn color, mottled on throat and jugulum with Prout's brown. 



Seasonal variation. — The color differences due to season are very 

 slight, probably in part, at least, because of the little wear to which 

 the plumage is usually subject. What little there is consists chiefly 

 in the somewhat more brownish or lighter shade of the dark parts, 



