Every few years I seem to get a melanistic squirrel who takes up residence in my back yard. I call them Ninja squirrels, they are stealthy little guys, and kinda cute, even taking into account that they’re really tree rats.
Black squirrels are one of those mutations that pop up from time to time. There must be some dominant gene in the local population. At first it doesn’t seem like being a black squirrel would have survival value. If you want to photograph them, you’ll quickly notice that in the harsh summer light, when the suburban woods are full of patches of bright sunlight and dark shadow, these guys can totally disappear in the deep shadows. Does that actually help them avoid their main predators, cats and hawks? Cats are naturally nocturnal hunters, and hawks prefer early morning or dusk, so yeah, maybe there is something there.
As usual, I get curious about such things and decided to at least hit Wikipedia to find out how this works. Turns out there is a dominate gene for pigmentation in lots of animals, and that it has some interesting side effects. Most research has been done on cats, but it most likely applies to other animals, perhaps even Ninja squirrels.
The camouflage theory certainly works for cats. The leopards which express this come from North and South America as well as parts of Malaysia. The same gene that causes the black color also conveys disease resistance. It’s believed the prevalence of black cats is at least partly the result of a viral plague somewhere in their genetic history. The disease resistance is likely the result of increased vitamin D production. Resistance to the effects of ultraviolet light is yet another bonus. Absorbing the extra heat during the day not so good, never having to worry about sunburn or skin cancer, that one is definitely a positive.
Black squirrels pop up all over North America, as far north as Canada. I guess these guys are always in the background, yet they’re not common enough to be seen on a regular basis. I’m not sure why I always seem to have one around, but I count it as a good omen.
This particular Ninja squirrel has been a great photo subject. He’s not very shy, even a little curious, but still that squirrel instant reflex time. A quick movement anywhere in the vicinity and he’s gone in the blink of an eye. I put out bird feed, and the squirrels in general always clean up anything that’s kicked out of the feeder. They have a particular affection for peanuts and sunflower seeds. Those little flakes flying about in the second shot are the husks of sunflower seeds. Ninja squirrel peels those things faster than you can see. All I’ve ever been able to catch with the camera is a few flying pieces. Since peanuts don’t grow anywhere near here, I have to put that skill down to some squirrel instinct. It’s just something they seem to know.
Just another great example of how having a camera helps you understand a bit more about nature.