1902.] F.¥mn—Abricpt Variation in Indian Birds. 8'1 



V". — On some cases of Abrupt Variation in Indian Birds. — By F. Finn, 

 B.A., F.Z.S., Deputy Superintendent of the Indian Museum. 



[ Received February 26fch ; Read March 5th, 1902. ] 



I. Albinistic variation m Dissemurus paradiseuSy Jlilthiopsar fuscus, 

 Acridotheres tristis, AND Pavoncella pugnax. 



The albinistic and other varieties which so frequently occur every- 

 where among birds are too frequently passed over by ornithologists as 

 mere " freaks " unworthy of careful consideration ; yet every now and 

 then occurs an instance of sudden and abrupt variation, of a type which 

 when found constantly is unhesitatingly allowed the rank of a species. 



It is true that the majority of albinistic specimens belong to a 

 form which appears no more capable of maintaining itself in nature 

 than is the perfect pink:-eyed albino ; at any rate, just as no pink-eyed 

 species of bird exists in the wild state, so we also find that no species is 

 splashed, pied, or mottled in the irregular manner characteristic of many 

 domestic birds and of the usual pied variety which occurs in wild ones. 



Such a specimen is the pied Bhimraj {Disseniurus paradiseus) figured 

 on Plate I., in contrast with the type of the species named by me (J.A.S.B. 

 LXYIII, Pt. II. p. 119) Dissemurus alcocki ; I have been induced 

 torefigure the latter in order to show that it is no mere albinism. The 

 pied bird had the base of the bill partly whitish, and even some of the 

 rictal bristles white; it is the only pied specimen of this species I have 

 ever seen, and I have examined many, both alive and dead. 



A more interesting and much rarer type of variety, however, is that 

 in which the markings are similar to those occurring in a natural 

 species. Such an one is the specimen of the Jungle Mynah (^thiopsar 

 fuscus) figured on plate II ; and catalogued by Anderson (Cat. Birds, Mus. 

 As. Soc. interleaved Museum copy) as " 577, one, albino, Moulmein, Major 

 Tickell."* In this bird the general plumage is white, with the quills, 

 both primary and secondary, and the tail feathers normally coloured. 

 The greater coverts are partly white and partly normal, and thus I am 

 inclined to suspect that this is a similar case to one which I have 

 recently observed in the Common Mynah (^Acridotheres tristis). In tliis 

 bird the plumage was originally all white, with the eyes, bill and feet 

 normal. Mr. Rutledge kept it for some time, and it began to change 



* This colouration of white body and dark quills and tail is normal in the 

 Javan Graculipica melanoptera, a bird which I was able to study in life in the 

 London Zoological Gardens in 1901. Since writing this paper I have seen another 

 grizzled specimen of Dissemurus paradiseus. 

 J. II, 11 



