THE BIRDS OF NORTHERN THAILAND 329 



In the mutant from which the misleading subspecific name is de- 

 rived, the breast, upper abdomen, and uppermost back are slaty gray 

 instead of golden-olive. This phase is known from Thailand by two 

 females taken in the neighborhood of Muang Chiang Dao, March 21, 

 1937 (Deignan), and April 26, 1937 (Greenway). 



In eastern Thailand certain individuals have been taken in which 

 the bright yellows are replaced by dull orange or yellowish green, and 

 such aberrant examples may also eventually be found in the North. 



Northern birds have the wing length varying in males from 82 to 

 82.8 mm., in females, from 79 to 81 mm., and thus just manage to ex- 

 ceed the lower limit of wing length given by Robinson and Boden 

 Kloss for their race major (Journ. Federated Malay States Mus., vol. 

 11, 1923, p. 55), here considered to be merely the normal yellow phase 

 of cinereoventris. 



PYCNONOTUS DISPAR MINOR (Boden Kloss) 



Thai Black-throated Yellow Bulbul 



Otocompsa flaviventris minor Boden Kloss, Ibis, 1918, p. 200 (Ko Lak [= Pra- 

 chuap Khirikhan], southwestern Thailand). 



Otocompsa flaviventris, Gyldenstolpe, Kungl. Svenska Vet-Akad. Handl., 1913, 

 p. 25 (Den Chai) ; 1916, p. 69 (Pha Kho, Khun Tan, Pang Hua Phong, Tha 

 Chomphu) ; Journ. Nat. Hist. Soc. Siam, 1915, p. 166 (listed). 



Otocompsa flaviventris flaviventris, Gyldenstolpe, Ibis, 1920, p. 492 ("Northern, 

 north-western . . . Siam"). — de Schauensee. Proe. Acad. Nat. Sci. Philadel- 

 phia, 1928, p. 568 (Doi Suthep) ; 1929, p. 540 (Doi Suthep, Chiang Mai, Chiang 

 Rai, Chiang Saen). — Deignan, Journ. Siam Soe. Nat. Hist. Suppl., 1936, p. 110 

 (Chiang Mai, Doi Suthep).— Riley, U. S. Nat. Mus. Bull. 172, 1938, p. 386 

 (Khun Tan, Mae Khan, Muang Pai). 



Eiathea flaviventris flaviventris, Deignan, Journ. Siam Soc. Nat. Hist. Suppl., 

 1931, p. 140 (Chiang Mai, Doi Suthep). — de Schauensee, Proc. Acad. Nat. 

 Sci. Philadelphia, 1934, p. 203 (Doi Suthep, Doi Chiang Dao). 



The yellow bulbul is very common or even abundant in suitable 

 territory throughout the northern provinces, from the level of the 

 plains to about 3,800 feet. It is most numerous in the mixed-deciduous 

 jungle, somewhat less so in the pa daeng of the foothills and plains. 

 At new settlements, where cultivated ground is of small extent and 

 surrounded by only partially cleared forest, it is likely to be as familiar 

 and fearless a dooryard bird as is Pycnonotus j. erythrotis in districts 

 that have endured human habitation over a longer period. 



Along streams and trails in the submontane regions it will be seen 

 in small, chattering flocks in the bamboos and lower trees. The crested 

 black head and yellow eye make it an unmistakable form. 



No definite information on the breeding season is yet available for 

 our provinces, but all adult specimens taken between July 22 and 

 October 28 are in postnuptial molt. 



