THE DUSKY THRUSH. 409 



paler ; tail as adult ; wing-feathers as adult but with considerably 

 less chestnut on outer webs ; greater coverts brown-black edged 

 chestnut -brown, inner feathers with narrow chestnut -brown shaft - 

 streaks ; median and lesser wing-coverts brown-black with narrow 

 pale buff tips and wide chestnut -brown shaft -streaks. Females 

 appear to be browner on upper-parts and have duller edgings to 

 wing-feathers and greater coverts. 



First winter. Male. Upper-parts and under-parts like adult 

 female ; amount and richness of chestnut on wing-feathers inter- 

 mediate between adult female and male, tips of inner secondaries 

 whitish ; inner greater coverts with outer webs more mixed with 

 blackish than in adult male, outer feathers with paler outer edges 

 than in adult, some feathers often with pale shaft-mark at tip ; 

 median coverts usually brown-black and buff with pale mesial 

 lines. Sometimes very difficult to distinguish from adult male. 

 The juvenile body -feathers, lesser and median, and varying number 

 of inner greater coverts are moulted Aug. -Oct., but not rest of 

 greater coverts nor primary -co verts, wing- or tail-feathers. 



First winter. Female. Upper-parts browner than adult 

 female, feathers of lower mantle and scapulars usually with pale 

 chest nut -brown or buffish marks ; breast more rusty-brown, not 

 so black ; flanks paler rusty-brown ; sides of belly and flanks often 

 with spots ; wings and tail browner and edgings of wing -feathers 

 and greater coverts more buffish, especially those of unmoulted 

 outer greater coverts, which usually have clearly defined shaft- 

 streaks ; median and most lesser coverts with chestnut -brown 

 shaft-streaks. 



Measurements and structure. <$ wing 128-137 mm., tail 87-96, 

 tarsus 29-34, bill from skull 21-24 (12 measured). wing 122-128. 

 Primaries : 1st 9-16 mm. shorter than primary -co verts, 3rd and 

 4th longest (4th rarely 1 mm. shorter), 2nd and 5th 4-7 shorter, 

 6th 15-21 shorter ; 3rd to 5th emarginated outer webs. Outermost 

 tail-feathers only very slightly shorter than rest, 12 feathers. 

 Other structure as in White's Thrush. 



Soft parts. Bill brown -black, base of lower mandible and 

 cutting edge orange ; legs and feet brown ; iris bright brown. 



CHARACTERS. No subspecies. T. naumanni is somewhat similar, 

 but always has considerable amount of chestnut on tail-feathers, 

 breast and flanks chestnut. Some examples are decidedly inter- 

 mediate and the two species appear to interbreed. Black of breast, 

 chestnut on wing -feathers, coverts and axillaries and conspicuous 

 eye-stripe distinguish it from other British Thrushes. 



BREEDING-HABITS. Popham found nests in small trees standing 

 alone, occasionally also on ground, but never more than 2 feet 

 from it. Eggs. 4-5, occasionally 6, once 7, ranging through same 

 variation as Blackbird and Fieldfare, markings being generally 



