White squirrels in the UK are a white version of the grey squirrel (sciurus carolinensis) or a white version of the red squirrel (sciurus vulgaris).
There are two types of genetic aberrations that cause the white coats. The first is:
1. Albinism - a congenital condition caused by an absence of melanin, which gives colour to the skin and hair, making the squirrel easily identifiable by the red eyes
2. Leucism - a condition which causes grey squirrels to have a partial loss of pigmentation affecting the skin and hair, but not the eyes, so while the squirrel’s fur may be white (or have patches of white), the eyes will remain dark.
There are significantly more albino squirrels in the UK than suggested.
I now have over 200 separate sightings recorded throughout the UK.
Online media searches throughout the UK claim that they are very rare, with statements such as 'wildlife experts estimate that there are just 50 in the UK' or 'the odds of seeing an albino squirrel is 1 in 100,000'.
In fact, using the wildlife experts ratio of 1:100,000 for a mammal giving birth to an albino, and the 2.4 million estimate of grey squirrels living in the UK , this would actually equate to just 24 albino squirrels in the UK.
White squirrels appear to be thriving in the UK.
You would, however, be right in thinking that given how conspicuous they are to predators, their chances of survival would be slim.
There are a few reasons why they may be thriving in the wild:
1. They are often found living in public places, such as parks, children's playgrounds, and cemeteries where predators tend to be low.
2. Within these parks and public areas, they have started to attract attention from local residents, who are making special trips to feed the squirrels and hope to see 'the white one'.
3. Scientific research carried out in 1997 by Glen Jeffrey (University College London) and Joana Visa Esteve (Barcelona University) showed that albino squirrels eyesight is not as defective as other albino mammals. They are thought to only have a 5% reduction in vision, compared to the non-albino grey squirrels.