GRASSHOPPER-WARBLER 



the same colouring, or whether the variations are sexual or 

 sporadic, further investigation can alone show. 



GEOGRAPHICAL DISTRIBUTION. 



Owing to certain peculiar characteristics of this species, 

 naturalists acquainted with its habits are comparatively few, 

 and consequently our knowledge of its distribution is incom- 

 plete. We may, therefore, find that certain features in this 

 distribution, which at the present time appear to us anoma- 

 lous, may, as our knowledge increases, be partly or possibly 

 wholly explained. 



Great Britain is apparently one of the principal breeding 

 grounds, although over the whole area it can only be described 

 as locally distributed. We find it rare in Cornwall, but in the 

 remainder of the southern counties, including Devon, a regular 

 but local visitor. Further north it appears to be more 

 common, and in parts of Oxfordshire, Cambridgeshire, 

 Gloucestershire, Worcestershire, Shropshire, Yorkshire, Cum- 

 berland, Durham and Northumberland it is numerous. 



The greater part of Wales is unsuited to its habits, con- 

 sequently it is very local ; I have, however, frequently heard 

 it in Anglesey. Proceeding north, over the border, we find 

 it gradually becoming scarce ; south of an imaginary line 

 drawn from the mouth of the Eiver Clyde to the Firth of 

 Forth locally distributed, but north of this line rare, and we 

 lose sight of it at Arisaig on the mainland and in the north- 

 west of Skye. In the Orkneys, Shetlands and Western Isles 

 there is no record of its occurrence. Westward we find it 

 occurring in the Isle of Man, and then we come to a large 

 breeding ground in Ireland, where it is generally distributed, 

 but especially numerous in the counties of Antrim, Dublin, 

 Wexford and Waterford. 



The task of forming a systematic distribution outside the 

 British Isles is by no means an easy one, and the difficulties 

 face us directly we cross the Channel. 



