154 Mr. C. B. Tlcehnrst oi [Ibis, 



enormous area in AfohaDistan the status of the two birds is 

 unknown. 



Turning to winter distribution, differences are aoain found ; 

 Ij'icata is the bird of the whole of Baluchistan, eastern 

 Persia down to S.W. Persia and also Sind ; in this area 

 capistrata is very rare, I find one record from Seistan, one 

 from Baluchistan, and four or five only from Sind. My own 

 experiences of these birds in Sind show well the difference 

 in distriI)ution : picata is a very common bird everywhere 

 and I must have seen hundreds ; of capistrata I obtained one 

 female and thought I saw one male ! In the Punjab both 

 species occur^ but capistrata is by far the commonest in most 

 parts. In Rajputana both occur, but picata is far the 

 commoner ; in the United Provinces only p)icata has been 

 found. As Hume says (S. F. iii. p. 475), "as you go south 

 and east towards their limit of distribution capistratahQCome^ 

 rarer and rarer, and there is a belt of lUO to 200 miles wide 

 where capistrata is rarely seen ; on the other hand, in the 

 extreme north-west (of the plains) capistrata is much the 

 most common and there is an intermediate zone where both 

 are equally plentiful." 



In the N.W. Frontier Province there is only Whitehead's 

 statement that picata is fairly common round Kohat and that 

 capistrata is very abundant. Such differences in distribu- 

 tion both in summer and winter cannot be explained by the 

 supposition of dimorphism ; in other dimorphic Chats there 

 is apparently no distributional difierence. 



That the white- and black-headed birds are not the result 

 o£ age is quite certain. Biddulph (S. F. ix. p. 321) first 

 pointed this out, and as one can easily pick out first-year 

 birds from adults by their brown, not black, flight-feathers 

 and primary coverts, so one can easily see that both forms 

 occur in both ages. Biddulph and Scully got an enormous 

 series of these birds in the breeding-season at Gilgit, and 

 found that picata was far the commoner, capistrata was rare 

 and some males were intermediate in the coloration of the 

 crown ; from the examination of these in the British 

 Museum and the few others I have seen from the Punjab in 



