STRANGERS OF THE SPRING. 45 



to frequent our islands for the purpose of repro- 

 duction. It should be remarked that spring is 

 the usual season for examples of rare Terns to 

 visit the British Islands birds which wander here 

 on their migration northwards ; just as autumn is 

 the time to expect stranger Gulls, which are driven 

 from their home in the Arctic regions by severe 

 weather. The Black Tern still visits the lowland 

 broads in spring, where it formerly used to breed ; 

 but the examples of the White-winged Black 

 Tern and the Whiskered Tern that reach this 

 country are lost and wandering birds, out of their 

 usual range. Of the Petrel family, the Dusky 

 Shearwater is an occasional wanderer to the 

 British seas in spring from its island homes off 

 the west coast of Africa ; and Wilson's Petrel, a 

 southern hemisphere species, though a stranger 

 of the spring to us, is in reality a winter wanderer 

 from its haunts in lonely Kerguelen Island in the 

 remote Indian Ocean. Our last stranger of the 

 spring is the Garganey. Many individuals of this 

 species, on their way north from their winter 

 quarters in the basin of the Mediterranean, visit 

 the British Islands, and some of them remain to 

 breed in districts where they are left unmolested. 

 This bird was much more plentiful with us before 

 the larger fens were drained. 



It is worthy of remark that all, or nearly all, 

 the birds that accidentally reach us in spring are 

 late migrants to Europe, and come with the last 

 wave of migration that spreads northwards at this 



