

The Urbanization of the Eastern Gray Squirrel in the United States (2013) - Thevet
http://jah.oxfordjournals.org/content/100/3/691.full

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chestnut-tree
On a slight tangent...grey squirrels are considered an invasive species in the
UK. They were not originally native to the UK, but after their introduction
from North America they quickly outstripped the native red squirrels in
population numbers. They are heavier than red squirrels and outcompete them
for food. They also carry a virus which is harmful to red squirrels but
harmless to themselves.

Grey squirrels are absent from most of mainland Europe (red squirrels are the
native species). However, there is a small population of grey squirrels in
Italy. The concern is that these grey squirrels may spread into other
continental countries and affect the native red squirrel populations.

Earlier this year, Imperial College London revealed details of a study into
the genetic diversity of Italian grey squirrel populations:

 _" Genotyping of grey squirrels sampled from Italy and the UK shows a direct
link between genetic diversity and their ability to invade new environments."_

[http://www3.imperial.ac.uk/newsandeventspggrp/imperialcolleg...](http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_5-6-2014-14-51-16)

