ISLAND LIFE 



35. Dolichonyx oryzivonis 



36. Pyrocephalus nanus 



37. P. minimus (Ridg.) ... 



38. Myiarchus magnirostri.- 



39. Zenaida galapagensis 



40. Buteo galapagensis .., 



41. Asio galapagensis 



42. Strix ])unctatissima 



ICTERID^. 



Ranges from Canada to Para- 

 guay. 



Tyraxnid.e. 



Allied to P. ruhincits of Ecua- 

 dor. 

 Allied to "West Indian species. 



Columbid.t:. 



/ A peculiar species of a S. 

 ( American genus. 



Falconid^. 



A buzzard of peculiar coloration. 



SXRIGIDiE. 



] Hardly distinct from the wide- 

 ■■■ \ spread A. hrachyotus. 

 . . . Allied to S. flammea but (juite 

 distinct. 



We have here every gradation of difference from perfect 

 identity with the continental species to genera so distinct 

 that it is difficult to determine with what forms they are 

 most nearly allied ; and it is interesting to note that this 

 diversity bears a distinct relation to the probabilities of, 

 and facilities for, migration to the islands. The excessively 

 abundant rice-bird, which breeds in Canada and swarms 

 over the whole United States, migrating to the West 

 Indies and South America, visiting the distant Bermudas 

 almost every year, and extending its range as far as 

 Paraguay, is the only species of land-bird which remains 

 completely unchanged in the Galapagos ; and we may 

 therefore conclude that some stragglers of the migrating 

 host reach the islands sufficiently often to keep up the 

 purity of the breed. Next, we have the almost cosmopolite 

 short-eared owl {Asio hrachyotus), which ranges from 

 China to Ireland, and from Greenland to the Straits of 

 Magellan, and of this the Galapagos bird is probably only 

 one of the numerous varieties. The little wood warbler 

 (Bendrceca aureola) is closely allied to a species which 



