NOVTTATEa ZOOI^OOICAE XXVI. 1919. 



41 



FUETHER NOTES ON SOME DICRURIDAE. 



By E. C. STUART BAKER, F.L.S., F.Z.S. 



OicTurus annectens. 



IN the Ibis, 1918, p. 226, Kloss has recently separated the Siamese form of 

 the Ci'ow-billed Drongo as Dicrurus annectens siamensis on account of the 

 alleged smallness of the bill. This diagnosis is to some extent confirmed by the 

 material in the British Museum, but not to the same extent by two birds collected 

 by Mr. E. G. Herbert. 



Kloss 's birds, which include three adults and two juv., have bills which 

 measure 87 mm. in breadth at the nostrils, and 85 mm. in height at the chin. 

 There are four birds in the British Museum from Siam, and these have the bill the 

 same size in breadth as given by Kloss, but in depth at the chin they are just 

 under 10 mm., practically the same as other birds from other areas. Of Mr. 

 Herbert's two birds, one collected at Mi Nam Kabren, some 100 miles N.E. of 

 Bangkok, has a bill only 83 mm. in width, but the other from Keo Tung Song in 

 S.W. Siam, close to where Kloss's birds were obtained, has a biU 10 3 mm. in 

 breadth. 



The following table gives the measurements of D. annectens over the whole 

 of its habitat. The width of the bill is taken at the nostrils and the depth at 

 the chin in the same way as taken by Kloss, a method which obviates vaiiation 

 due to difference in make up of skin and loss of feathers. 



and 



Area. 

 Oude, Nepal. 



A33ain 

 Central and North 



Burma 

 Cen. Burma and 



Tennasserim . 

 S. Malay Pen. 

 Borneo 

 Siam . 



BiU, breadth. 



Bill, depth. 



Wing. 



So. of 

 spedouju. 



10-1 mm. ( 9'0toll-5) 105 mm. (100 to 110) 1430 mm. (132-147) 

 10-Omm. ( 90toll"0) 107 mm. (100 to U'O) 138 3 mm. (132-145) 



10-8 mm. (10-0 to 12-0) 



irOmm. (lO'O tol2 0) 



10-0 mm. ( 9'0 to 12 0) 



8-5mm. ( S'Sto lO'S) 



lO'Smm. (lO'OtoirO) 



10-7 mm. (10-0 to U'o) 



102 mm. ( 95 to II'O) 



9'5mm. ( S'Sto HO) 



140'0mm. ( 

 138-5mm. ( 

 139'1 mm. ( 

 144*5 mm. ( 



131-147) 

 129-145) 

 124-147) 

 137-156) 



12 



15 



5 



30 



9 



The variation in both depth and breadth of bill is very great, but in Siamese 

 birds the latter dimensions are very small, in every case but one being below 

 the minima in other areas. It must also be noted that though they have the 

 smallest bill measurements the birds themselves are the largest of all. Thus, 

 in spite of the paucity of Siamese material, Kloss's sub-species must be maintained, 

 at all events until more material either confirms or disproves his diagnosis. I 

 therefore recognize two races of this species. 



(1) Dicrurus annecteris annectens. 



Buchanga annectens Hodge., Ind. Rev. L p. 326 (1837). 



Type in Calcutta Museum. 



Type Locality. Nepal. 



Size a trifle smaller, wing averaging just over 139 mm. 

 broad, measuring at the nostrils about 105 mm. 



bill decidedly more 



