THE BIRDS OF NORTHERN THAILAND 107 



of bamboo overarch ditches or quiet pools. It is highly tolerant of a 

 semiarid environment and, at Chiang Mai, I noted little diminution 

 in its numbers during even the driest months, when it was often seen 

 slinking across parched fields, where only the low bunds offered con- 

 cealment. It has a particular fondness for the thorny types of bamboo, 

 using them for roosting and nesting purposes, even when they are at 

 some distance from the nearest water, to and from which it travels 

 on foot. The vernacular name is derived from its song, the syllable 

 wak repeated many times in a loud, harsh voice, heard chiefly during 

 the rains and at night dominating even the unearthly din of the frogs. 

 The breeding season seems to coincide with the rainy months, during 

 which period I have often seen the black juveniles. 



An adult female had the irides garnet ; the frontal plate red ; the bill 

 green, with extreme tip violet-blue; the rictus violet-blue; the feet 

 and toes chrome-yellow ; the claws horn. A somewhat younger female 

 differed only in having the irides bright brown. 



The adult has the forehead, sides of the head, the throat, breast, and 

 upper abdomen white; the lower abdomen fawn color; the upper 

 flanks slate; the lower flanks and under tail coverts rufous; an in- 

 distinct black line bordering the white of neck and breast; the re- 

 maining plumage slaty olive, more slaty on the wings. 



GALLICREX CINEREA CINEREA (Gmelin) 



Chinese Watercock 



[Fulica] cinerea Gmelin, Systema naturae, vol. 1, pt. 2, 1789, p. 702 (China). 

 Gallicrex cinerea, Deignan, Journ. Siam Soc. Nat. Hist. Suppl., 1931, p. 169 

 (Chiang Mai) ; 1936, p. 81 (Chiang Mai). 



At Chiang Mai individuals in the brown nonbreeding plumage ap- 

 peared locally and in small numbers early in March, but the species 

 was really common only during the rains ; my extreme dates are March 

 5 (1931) and September 26 (1931). I have also seen the watercock 

 at Muang Phayao late in August, Doubtless it occurs throughout our 

 provinces during the wet weather. 



This large rail may be found in the flooded ricefields and in some 

 numbers amid the tangled vegetation of the larger marshes. When 

 open water must be crossed, it swims well, riding high and rather 

 resembling a duck. When alarmed it stretches up its neck and, at 

 short intervals, raises the tail with rapid jerks. Stomachs I examined 

 contained only seeds and other vegetable matter. 



Two males taken May 26 were in full nuptial dress and had the 

 gonads greatly enlarged; a juvenile collected July 25 is well grown 

 but completely lacks remiges and rectrices. 



The remarkable song is heard from the reedbeds all through the 

 summer, but only once, June 23, 1930, did I witness the curious per- 



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