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Alaska Department of Fish and Game


Invasive Species — Norway Rat (Rattus norvegicus)
Impacts

Species Affected

Because rats have a very broad diet, they can have a harmful affect on many different wildlife species. In Alaska, some of the worst problems have occurred in seabird colonies. For example, an island in the Aleutians, known as “Rat Island” because of its rat infestation, suffered significant losses to its seabird populations after a shipwreck accidentally transferred rats to the island over two centuries ago. An eradication program for the rats on Rat Island (2007- 2009) was successful, and bird populations on the island are already improving.

Aside from the predation pressure of rats on Alaskan wildlife, they also carry parasites, pathogens and diseases that can be harmful to other species as well as humans.