Such a rapid expansion of range is unprecedented for a native vertebrate (though invaders from Europe, such as the house sparrow and the Norway rat, have managed similar feats).
The threats posed by some species are obvious; for example, Norway rats are decimating seabird colonies on islands in Alaska where mammalian predators were naturally absent.
Although Alcatraz has no feral cats, which would be a major threat to the nesting birds, Norway rats were seen recently for the first time.
Today, Norway rats (aka brown rats) can be found on every continent of the world except Antarctica.
Invasive rodents, such as the Norway rat, are known to cause major disruptions to isolated ecosystems.
Definition of Norway rat in US English:
Norway rat
nounˈnɔrweɪ ræt
another term for brown rat
Example sentencesExamples
Invasive rodents, such as the Norway rat, are known to cause major disruptions to isolated ecosystems.
Such a rapid expansion of range is unprecedented for a native vertebrate (though invaders from Europe, such as the house sparrow and the Norway rat, have managed similar feats).
Today, Norway rats (aka brown rats) can be found on every continent of the world except Antarctica.
The threats posed by some species are obvious; for example, Norway rats are decimating seabird colonies on islands in Alaska where mammalian predators were naturally absent.
Although Alcatraz has no feral cats, which would be a major threat to the nesting birds, Norway rats were seen recently for the first time.