INTRODUCED RATS AND MICE 



Mus mascutus 



(W's^i^ 



"Mus miiscalus 





■>.»«w 



y*lfli'.-'- 



Distribution. — Practically all of North America 

 permanently inhabited by white man. These spe- 

 cies, native to the Old World, reached Alaska by 

 human transport, as stowaways on ships and 

 among food products. They have become estab- 

 lished and persist in the vicinity of human habita- 

 tions, where they are notorious pests. 



Races in Alaska. — The Norway rat, Rattus nor- 

 vegicus, occurs chiefly in or near the larger settle- 

 ments of southern and interior Alaska and at 

 Nome. After World War II, these rats were ex- 

 tremely numerous on Amchitka and other Aleutian 

 Islands. The house mouse, Mus my-seuhi-s domesti- 

 cus, exists in similar situations in southern Alaska. 

 It has also been introduced on St. Paul and St. 

 George Islands, in the Pribilofs; it has persisted 

 on St. Paul since 1872, but is apparently unable to 

 survive the winters on St. George. 



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