THE BIRDS OF NORTHERN THAILAND 365 



Khun Tan (whose summit is too low) and from Doi Chiang Dao 

 (which lacks suitable forest on the higher slopes). 



This bird travels in flocks of as many as 20 individuals, which keep 

 to the tops of the highest trees but attract attention by their constant 

 outcry and incessant flirting of the tail as they run along the branches. 

 De Schauensee observes (1929) that "their notes consist of a series of 

 jumbled whistles and squeaks and a rolling sound like krrr reminis- 

 cent of the winding of a large clock." Like other sibias, this species 

 congregates at flowering trees but may sometimes also be seen feeding 

 on berries. 



A specimen from Doi Ang Ka, April 15, had the testes greatly en- 

 larged. Examples in postnuptial molt have been taken at various 

 localities between November 12 and December 15. 



A breeding male had the irides brown-orange; the bill black; the 

 feet and toes dark plumbeous; the claws blackish brown. 



The long-tailed sibia has the entire upperparts deep slaty gray (the 

 wings and tail blackish) ; the outer secondaries with a large white 

 spot at the center of the outer web, forming a conspicuous speculum ; 

 the graduated rectrices broadly tipped ashy gray, above and below ; 

 the underparts ashy gray, somewhat albescent on the center of the 

 abdomen. 



LEIOPTILA CAPISTRATA MELANOLEUCA (Blyth) 



Tenasserimese Black-capped Sibia 



Sibia melanoleuca "Tickell" Blyth, Journ. Asiat. Soc. Bengal, vol. 28, 1859, p. 413 

 ("Mountainous interior of the Tenasserim provinces"; type specimen from 



Mount Muieyit, fide Tickell, Journ. Asiat. Soc. Bengal, vol. 28, 1859, p. 451). 

 Leioptila melanoleuca laeta de Schauensee, Proc. Acad. Nat. Sci. Philadelphia, 



1929, p. 470 (Doi Suthep, North Thailand). 

 Leioptila melanoleuca laeta, de Schauensee, Proc. Acad. Nat. Philadelphia, 1929, 



p. 534 (Doi Suthep) ; 1934, p. 194 (Doi Suthep, Doi Chiang Dao).— Deignan, 



Journ. Siam Soc. Nat. Hist. Suppl., 1931, p. 138 (Doi Suthep) ; 1936, p. 107 



(Doi Suthep).— Riley, U. S. Nat. Mus. Bull. 172, 1938, p. 357 (Doi Ang Ka, 



Doi Suthep, Doi Langka). 

 Leioptila melanoleuca melanoleuca, Chaskn and Boden Kloss, Journ. Siam Soc. 



Nat. Hist. Suppl., 1932, p. 244 (Doi Suthep). 



The present form is very common or even abundant in evergreen 

 forest at elevations in excess of 4,400 feet, on Doi Ang Ka occurring 

 from that altitude up to about 7,500 feet: it reaches its eastern 

 periphery of range on the highest peaks of the Khun Tan chain. 



At the summit of Doi Suthep, this delightful bird is rivaled in 

 numbers only by the bulbul, Pycnonotus f. vividus, and, thanks to 

 its complete lack of timidity, no species is more easily observed. In 

 small, loose bands (often accompanied by the other sibias) it explores 

 the epiphyte-laden trees, now ascending an upright trunk like a 

 Yuhi?ia, again swinging head-downward from the extremity of a 

 branch like a titmouse, in between running lengthwise along a bough, 



