THE BIRDS OF NORTHERN THAILAND 545 



The scarlet-backed flowerpecker is very common throughout the 

 lowlands of all the northern provinces, occurring both in gardens and 

 in the dry, deciduous forest; in the latter type of growth it ascends 

 the hills to about 1,800 feet. 



Sharing with the sunbirds the name nok kin pli ("bird that eats 

 the banana flower"), this diminutive species of the treetops is well 

 known to all residents of our area through its rapid flight, sharp notes, 

 and striking color pattern. In the deciduous jungle it is seldom seen 

 away from the clumps of mistletoe. 



Specimens with the gonads active have been taken at Chiang Mai 

 between December 27 and May 25, but January and February seem 

 to be the principal breeding months there. Young birds still in post- 

 natal molt but on the wing were collected March 30 and April 21, and 

 others in full juvenal dress, May 24; postjuvenal molt directly into 

 adult plumage appears in a series taken between May 20 and July 26. 

 Postnuptial molt is shown by birds shot between May 25 and August 

 24. An adult male of April 22 is in body molt, but it cannot be decided 

 whether this represents a prenuptial molt or an unusually early case 

 of postnuptial molt. 



An adult male in breeding condition had the irides dark brown ; the 

 bill black; the feet, toes, and claws black. An adult female differed 

 in having the irides gray-brown and the basal half of the mandible 

 plumbeous. Juveniles have the irides brown ; the bill with the basal 

 half or more bright orange and the rest horny brown ; the rictus and 

 interior of the mouth bright orange ; the feet, toes, and claws brown- 

 ish slate. The bill of young birds assumes the colors normal to adults 

 during the postjuvenal molt. 



The adult male has the forehead, crown, nape, back, rump, and 

 upper tail coverts shining crimson -scarlet (with the black bases of the 

 feathers showing through in places) ; the scapulars, upper wing cov- 

 erts, remiges, and rectrices black, their exposed portions glossed with 

 metallic blue ; the lores, supercilium, and sides of the head, neck, and 

 throat slaty black, paling to slate on the sides of the breast and to ashy 

 on the flanks; the remaining underparts (including the under tail 

 coverts) pale buff or buffy white; the under wing coverts and axil- 

 laries pure white. The adult female has the rump and upper tail 

 coverts shining crimson-scarlet and the rectrices black, glossed with 

 metallic blue, but the remaining upperparts dull brownish olive (more 

 or less strongly suffused with rufescent), each feather of the forehead 

 and crown with a minute blackish central spot ; the sides of the head, 

 neck, throat, and breast olivaceous-ashy; the remaining underparts 

 pale buff or buffy white, suffused with olivaceous along the flanks; 

 the under wing coverts and auxiliaries pure white. The juvenile re- 



