INTRODUCTION. ix 



followed shortly afterwards by the females, and lastly 

 by the young birds, which do not usually take so 

 long a flight, some perhaps not getting farther than 

 the European shores of the Mediterranean. Roughly 

 speaking, there are three lines of migration taken by \^ 

 birds whose route lies southward in autumn, namely, 

 the Spanish coast in the neighbourhood of Gibraltar, 

 the Italian coast by Sicily, and the Greek coast by 

 Cyprus. The first lands them on the opposite coast 

 of Barbary, the second on the shore of Tunis, the 

 last on the Asiatic coast at Tripoli. It is remarkable 

 that these three routes cross the sea where it is 

 narrowest and the most shallow, and were probably 

 dry land in comparatively recent times. 



Several birds, such as the Ring-Ouzel, Golden 

 Plover, &c., pass through Dorsetshire on their migra- 

 tion northwards to breed. The migratory line of 

 the Dotterel being outside our border, the bird visits 

 us rarely; its last occurrence was in 1883.^ A vast 

 number of birds push their way as far north as the 

 ice-line, a course which some naturalists assign to 

 an hereditary instinctive impulse to return to the 

 breeding-homes of their progenitors, which had an 

 equable climate before the rigours of the glacial 

 period had set in, and had forced them southward 

 to seek food and shelter. Thus it is supposed the 

 migratory habits of birds originated, and continue to 

 the present day. 



Seeing that the course of many birds on migration 

 lies far east of these islands, any casual visitor 



1 See Proc. Dorset N. II. Field Cluh, vol. vi. p. 29 (1885). 



