Unfortunately it is quite impossible to give any key which will 

 render it easy to discriminate these races one from another, as all the 

 differences are ones of comparative depth of colouring only, although 

 typical specimens are easily separable when laid alongside one another. 



Roughly speaking it may be said of the five subspecies that — 



Streptopelia turtur turiur is a very rare straggler from north Persia 

 and Asia Minor. 



S. turtur arenicola is an equally rare straggler into north-west India 

 from southern Persia and Arabia. 



S. turtur ferrago is a migratory bird, breeding in the Himalayas 

 and visiting almost every part of India in the cold weather. 



S. turtur meena is the common resident form over Continental 

 India, eastern India, and Burma. 



S. turtur orientalis is the resident species in the extreme north. 



From the key it is seen that I consider all the above birds to be 

 subspecies of Streptopelia turtur, whilst Hartert and others consider 

 S. orientalis m-ientulis and S. orientalis meena form another group. 

 To me, however, they all appear to be geographical races of the same 

 species, and if it is correct to say that turtur turtur grades into turtur 

 arenicola, and that again into turtur ferrago, so it seems to me that turtur 

 arenicola grades into turtur orientalis, and there are a few birds in the 

 British Museum Collection which form an excellent connecting link 

 between the two subspecies. 



