THE BIRDS OF NORTHERN THAILAND 401 



Beyond the fact that it is less strictly confined to the immediate 

 vicinity of watercourses than its relatives and may often be seen run- 

 ning nervously along some forest track, especially one that crosses 

 and recrosses a small stream, the habits of this species are much like 

 those of schistaceus. 



Gyldenstolpe took juveniles at Doi Pha Sakaeng, July 16, and at 

 Khun Tan, September 13, while de Schauensee collected one on Doi 

 Suthep, July 18. 



My specimens had the irides dark brown; the bill black; the feet, 

 toes, and claws fleshy white. 



The adult has the forehead and semierectile feathers of the fore- 

 crown white ; the rest of the head (including the throat and neck) , the 

 breast, and upper back black; the lower back, rump, and upper tail 

 coverts white ; the wings black, the greater coverts broadly tipped with 

 white to form a Aving bar (which seems to be connected with the white 

 of the back) , the inner secondaries with broad concealed white bases 

 and narrow white tips; the deeply forked tail with the two outermost 

 pairs of feathers white, the others black with conspicuous white tips ; 

 the abdomen, flanks, and under tail coverts white. The juvenile dif- 

 fers in having the head, upper back, throat, and breast deep brown, 

 the feathers of the two last parts with fulvous shaft streaks ; the white 

 wing band suffused with buff. 



ENICURUS SCHISTACEUS (Hodgson) 



Slaty-backed Forktail 



[Motadlla (Enicurus)^ Schistaceus Hodgson, Asiatick Researches, vol. 19, 1836, 

 pp. 189-190 (Nepal). 



Henicurus schistaceus, Gyldenstolpe, Journ. Nat. Hist. Soc. Siam, 1915, p. 170 

 (listed) ; Kungl. Svenska Vet.-Akad. Handl., 191G, p. 49 (Khun Tan, Doi Pha 

 Sakaeng). 



Enicurus schistaceus, Gyldenstolpe, Ibis, 1920, p. 476 (Khun Tan, Doi Pha 

 Sakaeng). — de Schauensee, Proc. Acad. Nat. Sci. Philadelphia, 1928, p. 564 

 Doi Suthep); 1934, p. 209 (Doi Suthep, Doi Chiang Dao).— Deignan, 

 Journ. Siam Soc. Nat. Hist. Suppl., 1931, p. 142 (Doi Suthep). 



Enicurus schistaceus schistaceus, Deignan, Journ. Siam Soc. Nat. Hist. Suppl. , 

 1936, p. Ill (Doi Suthep).— Riley, U. S. Nat. Mus. Bull. 172, 1938, p. 401 

 (Doi Langka, Doi Hua Mot, "Ban Padieng," Huai Lak, Song Khwae valley). 



The slaty-backed forktail, known only from the provinces of Mae 

 Hong Son, Chiang Mai, and Chiang Eai (Kiu Chang Kong, on the 

 border of the French Enclave), is the commonest of its genus in our 

 area. It is numerous on Doi Ang Ka from 3,500 to 5,000 feet and on 

 Doi Suthep between 2,000 and 3,600 feet and, at least in winter, occurs 

 also where brooks debouch from the hills into heavy forest at the level 

 of the plains, just as does the preceding species. 



Within its range on Doi Ang Ka and Doi Suthep, pairs of this 

 forktail inhabited every stream, both where it tumbled torrentially 



