THE BIRDS OF NORTHERN THAILAND 419 



Notodela leucura, de Schauensee, Proc. Acad. Nat. Sci. Philadelphia, 1929, p. 543 

 (Chiang Saen). 



Muscisylvia leucura, Deignan, Journ. Siam Soc. Nat. Hist. Suppl., 1931, p. 142 

 (Doi Suthep) ; 1935, p. 65 (Doi Ang Ka) ; 1936, p. 112 (Doi Suthep).— DE 

 Schauensee, Proc. Acad. Nat. Sci. Philadelphia, 1934, p. 210 (Khun Tan).— 

 Riley, U. S. Nat. Mus. Bull. 172, 1938, p. 405 (Doi Langka, "Ban Padieng"). 



The groundrobin occurs in dense, damp evergreen forest (rarely in 

 adjacent areas of thick bamboo), at elevations from the level of the 

 plains (Chiang Saen) to 5,200 feet (Doi Ang Ka). In addition to 

 the localities named above, it has been found at Doi Nang Kaeo, Doi 

 Chiang Dao, and Phu Kha. The sole record for Doi Suthep is a 

 female taken at 3,200 feet, February 24, 1931. 



This shy species keeps to the ground in heavy forest along streams 

 or in shady ravines and is not likely to be seen unless it comes out 

 for a moment onto some jungle track. On Doi Ang Ka, between 4,400 

 and 5,200 feet, in April, I often heard it singing ; the song, short but 

 sweet and strong, is reminiscent of the songs of the American thrushes 

 of the genus Hylocichla. 



A male of November 12 is in postnuptial molt ; others of September 

 2 and December 5 are in postjuvenal molt. Young birds of either sex 

 molt directly from the juvenal dress to that of the adult but the 

 change is not always complete the first year: a male of December 7 

 (not molting) is in wholly adult plumage except for the retention 

 of the juvenal greater upper wing coverts; another of May 6 (not 

 molting) has not only these juvenal wing coverts but the feathers at 

 the sides of the upper back colored exactly as in the adult female 

 and the feathers of the breast tipped full rufous. An old female of 

 February 28 has some of the scapulars blue, as in the male, and the 

 rectrices suffused with blue. 



An adult male had the irides brown ; the bill black ; the feet, toes, 

 and claws blackish brown. An adult female had the irides dark 

 brown ; the bill black, with the base of the mandible fleshy ; the rictus 

 and interior of the mouth yellow; the feet and toes horny violet; 

 the soles white; the claws horn. 



The adult male has the forehead, forecrown, eyebrow, and point 

 of the shoulder shining blue; the remaining upperparts (including 

 the wings) deep blue; the rectrices black, all except the central and 

 outermost pairs with a patch of pure white at the base of the outer 

 web (outwardly decreasing in extent) ; some of the feathers at each 

 side of the lower throat with pure white bases, to form two small, 

 concealed patches ; the feathers of the lower flanks with at least part 

 of the bases white, to form larger concealed patches; the remaining 

 underparts deep blue (so dark on the breast, throat, and chin as to be 

 almost black). The adult female has the upperparts olivaceous- 

 brown, suffused with rufous on the mantle; the remiges edged with 



