VIEWS ON MIGRATION. 23 



{JEgialitis minor) is a bird of passage in the 

 northern portions of its range, but resident in the 

 basin of tlie Mediterranean, the migratory indi- 

 viduals extending as far north as lat. 60° in summer, 

 and as far south as the Equator in winter. Even 

 the Common Sandpiper [Totanus liypoleucus) is by 

 no means uniformly migratory. Few birds are 

 more regular in their appearance in spring upon 

 our upland streams and pools than the dainty 

 " Summer Snipe," and yet in the basin of the 

 Mediterranean many individuals have dropped the 

 habit of migration altogether, and have become 

 sedentary. The Redshank {7'otanus calidris) is 

 even more irregular in this respect. In the north 

 of its area it is migratory, but in the basin of the 

 Mediterranean it is resident, and yet the winter 

 passage of many individuals of this species extends 

 south to the Cape Colony. Many individuals of 

 various species of Ducks have also ceased to 

 migrate, and have become residents in our islands 

 within comparatively recent times. Among these 

 may be mentioned the Tufted Duck {Fuligula 

 cristata) and the Pochard {Fuligula ferina). In 

 some cases the cessation of migration has led to 

 physical change, and the segregation of local 

 southern races. One instance of this I can here 

 call to mind is the small Indian race of the Little 

 Ringed Plover {jEgialitis Jerdoni). Another in- 

 stance is probably presented in the two races 

 of Ringed Plover {yEgialitis hiaticiila, and jE, 

 Idaticula major), the former migratory, the latter 



