A little squirrelly

The most common tree squirrel species in northeastern North America is Sciurus carolinensis (the eastern grey squirrel).  Typically, these squirrels are, well…grey!  But in a few of the places I have lived, a more unusual squirrel fur colour has dominated.

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Black Grey Squirrels!!

This dark morph is called a melanistic form.  The allele for the dark fur colour is an example of incomplete dominance, meaning that a breeding pair with one black adult and one grey adult will yield 25% black offspring, 25% grey, and 50% brown-black…you know, if they follow Mendelian inheritance.  (Which fur colour usually does, but I’m shooting from the hip here, so humour me.)

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Why are you following me around with a camera, human?

Some hypothesize that the darker colour is more effective in colder climates (because it absorbs more heat), but I have not found a scientific study to back up this claim.  Certainly, the squirrel is low on the food chain, and its camouflage is probably crucial to its survival.

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Where would the dark colour blend in better?

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On black drainage pipes of course! Its natural habitat!!

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Not so much in leaves?

And just for good measure, here is our grey grey squirrel friend.

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7 thoughts on “A little squirrelly

    • I did read something about black squirrels in the UK…I know that the grey squirrel is a terrible pest there. From what I can tell, it is not well understood why the black morph dominates in some areas and not others, even in its native range.

  1. Never seen one in the UK, but you get black ones or at least very dark ones, in NYC, e.g. in Central Park. It was a surprise the 1st time I saw them there – I’d never seen them before. RH

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