472 BULLETIN 186, UNITED STATES NATIONAL MUSEUM 

 PHYLLOSCOPUS SCHWARZI (Radde) 



Thick-billed Willow Warbler 



Sylvia (Phyllopneuste) Schwarsi Radde, Reisen im Siiden von Ost-Sibirien, vol. 2, 

 1863, pp. 260-263, pi. 9, fig. 1 (Tarai-nor, Davuria, East Siberia). 



Herbivocula schwarsi, de Schauensee, Proc. Acad. Nat. Sci. Philadelphia, 1929, 

 p, 555 (Mae Rim) ; 1934, p. 229 (Doi Suthep, Doi Chiang Dao).— Deignan, 

 Journ. Siam Soc. Nat. Hist. Suppl., 1931, p. 149 (Mae Rim) ; 1936, p. 116 

 (Chiang Mai. Doi Suthep).— Riley, U. S. Nat. Mus. Bull. 172, 1938, p. 431 

 (Doi Suthep, Doi Langka, Lampang). 



Phylloscopus afflnis, de Schauensee, Proc. Acad. Nat. Sci. Philadelphia, 1934, 

 p. 229 (Doi Suthep). — Deignan, Journ. Siam Soc. Nat. Hist. Suppl., 1936, 

 p. 116 (Doi Suthep). 



The thick-billed willow warbler is a not uncommon winter visitor to 

 our area, where it has been noted from November 5 (Doi Mae Lai) to 

 April 2 (Doi Suthep) ; it occurs in the lowlands and also at suitable 

 places on the mountains to 5,400 feet. Two females taken by Smith at 

 Lampang, November 17, 1928, are the only examples yet known from 

 the districts east of the Khun Tan chain but the species is almost cer- 

 tain to turn up in every one of our provinces. 



This is a bird of the dry jungle, on the plains and lower slopes of 

 the hills haunting the same places as the forms of Phylloscopus ar- 

 mandii, at higher elevations keeping to the grass and undergrowth of 

 the oak and pine forests. 



Prenuptial molt is shown by a skin from the vicinity of Chiang 

 Mai, March 20. 



A male had the irides dark brown; the maxilla dark brown; the 

 mandible fleshy, yellow at the base ; the interior of the mouth yellow ; 

 the feet and toes fleshy yellow ; the claws horny brown. 



The present species appears with us in two types of plumage. One 

 has the entire upperparts olivaceous-brown ; the lores and postocular 

 streak blackish brown; the supercilium pale buffy; the underparts 

 whitish, sullied with pale buffy brown (especially on the breast) and 

 becoming pale rufous-buff along the flanks and on the under tail 

 coverts. The second, which probably represents the first-winter dress, 

 is similar but has the olivaceous-brown of the upperparts more or less 

 strongly suffused with ruf escent ; the underparts as in the other type 

 but with the ground-color pale yellow instead of whitish. 



P. schwarzi, in the latter livery, is likely to be confused with P. 

 armandii. Ticehurst says (Systematic review of the genus Phyllo- 

 scopus, 1938, p. 96) : "Immediately recognisable from armandii by the 

 fact that if there is yellow in the underparts this is uniform and never 

 ntreaked with brighter yellow" 



