Answer to Freak of the Week #2


Black phase of the Eastern Gray Squirrel

Several of you got the right answer to this week’s Freak of the Week! Normally we don’t like red-eye in photographs but in this case it was perfect for the Halloween Squirrel! Read on for more info on this interesting squirrel.

Ohio has four native species of tree squirrels, the Eastern Gray Squirrel, the Eastern Fox Squirrel, the Red Squirrel, and the Southern Flying Squirrel. Though two of these are named after the coloration of their fur, this photo is actually of a black, or melanistic, phase of the Eastern Gray Squirrel (Sciurus carolinensis). The gray squirrel comes in a variety of coat colors, from the typical gray, to black, to white, or a combination of these colors. The white coloration is often called an albino, but albinism in squirrels is somewhat rare, and a white coat is more often simply a genetic color variance.
So why are some gray squirrels black!? Its been discovered that the black color phase is more common in the northern part of the squirrel’s range, and the dark color is believed to be involved in thermoregulation. The black phase has been shown to have an almost 20% lower heat loss in colder temperatures. Some feel that another factor might be the increased ability of darker squirrels to be camouflaged in the denser northern forests. One theory is that the black color phase was actually more common in the original old-growth forests, and loss of these forests has provided an advantage for todays gray coloration. Its interesting too that the Red Squirrel (Tamiasciurus hudsonicus) is normally found in thick forests and is a very dark red. It’s so dark that it appears almost black as it scurries through the deep shadows of the forest.

 

Posted October 25, 2013

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