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Friday, January 08, 2010

The Grey Squirrel

The Grey Squirrel gets a really bad press. It is blamed for the fall of the Red Squirrel and for eating the eggs of woodland birds.

Although I wish it wasn't here I have to accept it is and it is one of the first wild animals that many kids will see.

I was interested to read that a new survey from the British Trust for ornithology claims that the Grey does not have a significant impact on the populations of many of England's woodland bird species.

There is some evidence that grey squirrels may locally suppress the populations of some species but they do not appear to cause the birds any widespread or lasting harm.

The BTO's Dr Stewart Newson says:

Grey squirrels are very unlikely to have driven observed declines in woodland birds in recent years

Of the 38 bird species, a statistically significant relationship between grey squirrel and bird population sizes was found for 12 species.

Of those, squirrels appeared to have a positive impact on seven bird species, a correlation probably caused by both mammal and bird species benefiting from similar changes to their habitat.

Grey squirrels had a negative impact on just five: the common blackbird, Eurasian collared dove, green woodpecker, long-tailed tit and Eurasian jay.

Of these species, the most convincing evidence is for blackbird and collared dove.

The Grey Squirrel may be predating on these two species but the overall number of blackbirds and collared doves has gone even where grey squirrels are common (the increase is greater where there are no Squirrels).

If you are keen to read more.

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