48 GEOGRAPHICAL DISTEIBUTION. 



one thousand miles from the nearest continental coast. Among 

 these are the kestrel, hoopoe, oriole, and snow-bunting, and not 

 improbably also swallows, larks, and grebes.* If, then, birds 

 may be drifted by accidental storms to a distance of one thou- 

 sand miles in a direction contrary to that of the prevalent winds, 

 it may be asked, Why may they not be thus drifted, at least 

 after their first landing-place, another one thousand or two thou- 

 sand miles further ? In other words, if European birds are carried 

 to the Azores, why are they not at intervals also transported from 

 there to the American coast? This question can, with our present 

 knowledge, not yet be answered. Three or four species of European 

 birds have been noticed in the Bermuda Islands — the wheat-ear f Saxi- 

 cola oenanthej, the sky-lark (Alauda arvensis), the snipe (Gallinago 

 media), and tlie land-rail (Crex pratensis) ; but three of these are 

 also found in Greenland or on the North American mainland, while 

 the fourth, the sky-lark, appears to have been brought over in, or 

 to have escaped from, a, ship.t In an ocean studded with islands, 



* Most of the resident land-birds of the Azores are identical with forms 

 found in Europe and North Africa, and it, therefore, becomes impossible to 

 ascertain how many of the individuals actually peopling the islands may not 

 have boon recently transported from the mainland. It is only under excep- 

 tional circumstances — barrinij the case of recognised stragglers — that such 

 wanderers can be determined. 



+ The total number of European birds known to have found their way 

 across the Atlantic to the American shores (including Greenland) is, accord- 

 ing to Freke ("Zoologist," 1881), thirty-seven, of which Greenland counts 

 about thirty, and the Eastern United States only twelve. This determination 

 naturally excludes all birds that have been artificially introduced. Of the 

 twelve species occurring in the Eastern United States, six aj-e swimmers and 

 five waders, and only one (and that somewhat doubtful, Buteo vulgaris, re- 

 ported to have been obtained in Michigan, in October, 1873) is a true land- 

 bird. The wheat-ear, referred to as occurring in the Bermudas, is considered' 

 a member of the North American fauna. The number of species of American 

 birds crossing the Atlantic in the contrary direction is, according to the same 

 authority (" Proo. Eoyal Dublin Soc," 18S1), sixty -nine, of which twenty- two 

 are swimmei-s, sixteen waders, and no les-; than thirty-one land-birds. The 

 last include, among other forms, representatives of the genera Turdus (four 

 species I, Galeoscoptes, Eegulus, Dendroeca, Hirundo, Loxia, Zonotricliia, 

 Ceryle, Coccyzus, Pious, and several species of birds of prey. The bald- 

 headed ea^lc has been recorded from Sweden. It is significant that, of the 

 forty-seven species of waders .ind land-birds, only two are known from Ice- 

 land (Falco candicans and Numenius Iludsonioua) and none from the Faroe 



