180 MAMMALS OF THE PACIFIC WORLD 



creased enormously. For a while dogs lived on the island but 

 they have disappeared. 



The Galapagos Islands, situated more than five hundred 

 miles from the coast of Ecuador and separated from it by water 

 more than a thousand fathoms deep, have probably never been 

 in contact with the continent. Yet they are inhabited by several 

 rats of a tropical American group related to our rice rats 

 {Oryzomys). Although these rats have been isolated from one 

 another on the various islands for a long enough period of time 

 to allow a number of races and species to develop, they have 

 not diverged enough from the mainland forms to be considered 

 a separate genus. A bat (Lasiurus) closely related to the red 

 bats of the Americas and the Hawaiian bat, is also found on 

 the islands. Some species of this genus normally make long 

 migratory flights ; of all the American bats they are the most 

 likely ones to be carried far out of their usual range. The ships 

 of whalers and sealers used to put in at the Galapagos and for 

 many years a penal colony was located there. As a result house 

 rats and mice have invaded the islands. Liberated pigs, cattle, 

 and goats have gone wild, doing much injury to the native 

 vegetation. 



The Pacific islands from the Solomons and the Northern 

 Micronesian group to Hawaii, the Galapagos, and Juan Fer- 

 nandez are all truly oceanic. On a basis of their mammals they 

 cannot be related closely to the faunal regions used here. The 

 Galapagos and Juan Fernandez Islands may be considered Neo- 

 tropical or South American. 



