Almanac: Black Squirrels

Black squirrel. Photo: flckr.com. Creative Commons

On a visit to Ottawa in the early ’90s I was walking with friends along the Rideau River when I spotted a jet-black animal climbing up a tree. I did a double-take. “Is that a squirrel?” I asked my friends. They sort of shrugged and said, “Well… yeah… of course.” I explained that where I was from (Rochester, New York, at the time) squirrels are grey, not black. My friends found this only mildly interesting and the conversation moved on, but I kept thinking about it. I had done an informal study of eastern gray squirrels as part of a course in wildlife biology and nowhere in the reading I did for that study were black variants of the species mentioned.

It was probably at least a decade ago now that I saw my first black squirrel in Amherst. Since then, I’ve seen quite a few in my neighborhood, adjacent to the Town center, although never in my own yard, which continues to be dominated by dozens of gray squirrels drawn to my large burr oak and black walnut trees.

I have a grudging admiration for these animals. Admiration because they’re obviously a successful, resourceful species honed to squirrely perfection by millions of years of evolution. Grudging because the varmints can be real pests. One year, at least one (though I suspect several) infiltrated my attic and stashed hundreds of walnuts there. The industrious little buggers proceeded to loudly gnaw on the hoard throughout the winter, which was highly disconcerting. No amount of banging and cursing persuaded them to leave permanently. I solved the problem the next spring by having the large hemlock adjacent to the house removed. The hemlock branches overhung the roof, providing the squirrels an easy on-ramp to my attic via some small holes gnawed through the eaves.

I believe removing the tree annoyed the squirrels mightily, and they decided to plot bloody revenge. It was only about a month after the tree was gone that I went out to my back deck to fire up my propane grill for the first time. I was just about to click the lighter when I smelled gas. A lot of gas. “What the…??” Bending down to take a look I saw that the rubber hose connecting tank to grill had been gnawed nearly all the way through, allowing the gas to spew forth in an invisible — and potentially disastrous — cloud. I imagined the furry demons watching from the trees eagerly awaiting my immolation, and then chattering ruefully among themselves when I narrowly escaped.

But back to the black squirrel story.

The local blacks squirrels did not, as I had thought, represent the leading edge of a slowly expanding population originating in Canada. There is some expansion of that population, but our black squirrels have a more interesting origin. In the late 1940s, the founder of Stanley Park in Westfield, the businessman Frank Stanley Beveridge, was given a gift of some black squirrels from Michigan. Set loose in the park, the squirrels thrived and have been expanding their range locally ever since.

The black squirrels are not a separate species—meaning they can mate with the native gray squirrels and produce viable young. The black fur is caused by the deletion of a gene involved in creating the fur color. The deletion is recessive, which means that jet-black squirrels will only arise from the mating of two black squirrels. But the details of the genetics appear to be complicated — or, at least, more complicated than I have the energy to untangle. I have read that an in-between brown/black fur color is possible due to mating of a black squirrel with a gray squirrel, and that this is due to “incompletely dominant” genes of the gray squirrel. But I have yet to observe any of these in-between squirrels. (If you’ve seen such critters, leave a comment below.) 

Whether there are any behavior differences between the two color variants remains unsettled. One study found that black squirrels were less likely to flee when they heard the sound of a red-tailed hawk, a major predator, leading the authors to suggest that black squirrels are “bolder.” (Seems to me you could argue, equally, that the black squirrels are more oblivious to danger.) Another study found no differences in the behavior of gray vs. black squirrels in response to simulated attacks by either humans or dogs.

Some evidence suggests that black squirrels can out-compete and displace gray squirrels, which may be happening here, although I don’t know of any research on the issue. In England, captive gray squirrels imported from the U.S. escaped and have been outcompeting the native red squirrels there since the late 19th century. Black variants have occurred naturally, and now the black variants are increasing their geographic range within the gray squirrel population.

Whatever their color, you can see squirrels being active all year, unlike their cousins the chipmunks, which hibernate during winter. By this time of year, the gray squirrels I see are looking pretty lean, having lost most of the fat they put on in the fall to help get them through the winter. Squirrels eat all sorts of things besides nuts: wild fruits and berries, bark, tender young tree buds, mushrooms, insects and their larvae, and occasionally even baby birds. Of course, they’re not above dining on human garbage and compost either.

The squirrels bury many of the nuts they gather in fall, finding them again in the winter with their extraordinarily keen sense of smell. Of course, they don’t find all the nuts, which is fortunate for the walnuts and oaks. Without the squirrels’ help, the nuts would fall to the ground under their parent tree — just about the worst spot for them to sprout.

Now, it’s possible that black squirrels are just as evil… er… I mean, cunning… as their gray counterparts, but I find them much more beautiful than the gray versions and so, for now, I’m rooting for them. I would welcome them to my yard if I could do so. At least until they try to kill me.  

Almanac is a regular Indy column of observations, musings, and occasional harangues related to the woods, waters, mountains, and skies of the Pioneer Valley.

Stephen Braun has a background in natural resources conservation, which mostly means he is continually baffled by what he sees on explorations of local natural areas. Please feel free to comment on posts and add your own experiences or observations. You can also email at: braun.writer@gmail.com.

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16 thoughts on “Almanac: Black Squirrels

  1. I agree with you that black squirrels are pretty adorable. But their grey cousins are evil geniuses that render the term “squirrel proof feeder” oxymoronic. Of course I might feel differently if it was actually black squirrels that were pillaging my feeders. We get the occasional one on the deck but I mostly see them elsewhere in town. As for your experience with the gas leak – I would bet that the sabotage was deliberate. Squirrels are retributive. Once, when I failed to fill our two bird feeders for a couple of days, both feeders disappeared. We found them a few days later in the woods behind our house, vandalized. It wasn’t bears. It was squirrels. Who among us doesn’t have a squirrel vandalism story? And while the squirrels you’ve been observing may have a lean spring look, those who visit my deck are surprisingly portly

  2. The Haverford College campus sports a scurry of the rare black squirrels: they eventually became the official mascots for the athletic teams. Western Kentucky University displays a dray of unusual white squirrels. But my late father was most vexed by a barnful of common grey squirrels, slowly chewing their way through the cardboard boxes stored there, and quickly shredding the contents….

  3. Ha! That’s great Rob…I didn’t know about either “scurry” or “dray” as names for a group of squirrels…thanks for sharing that. And you remind me that I have heard of some albino squirrels in the Mt. Warner area of Hadley…have you seen any?

  4. Here on Jeffrey Lane live a few black squirrels. One female has been here for about five years and each spring, after getting raped by a squadron of gray squirrels, has her litter in a giant oak tree on my neighbors front lawn. This past year two of the kits were gray, two black.

    For a few years now I have been training the neighborhood squirrels with voice commands to sit up and face me in a designated area. Those that learn the trick get a peanut. The range of squirrel personalities is interesting. Pesky, a gray squirrel, learns fast but pushes boundaries. Bronzie got bored with peanuts and now rarely stops by. Blackie, the female who lives in the oak, learned this trick in about five minutes, unlike most of the grays who take days or even weeks to figure out the routine. Whether this is a gender thing or it says something about the intelligence of the black mutation is being tested as one of her offspring, Baby Blackie (sex still undetermined), is now coming around and studying me carefully.

  5. We have black squirrels in our yard in Cushman. One was cited a few years ago and now we count four. We have since also noted two squirrels with dark brownish/black tails and dark gray bodies. We have way too many gray squirrels, in particular, because a number of them are too bold and clever for our liking. We once also had some of these in the attic and had to catch them 1st thing in the morning with a “Have a Heart” trap set there. It took three 6:00am rides up Route 63 (squirrels will find their way back home with 10 miles) where we released them and cutting down a birch tree and fixing the metal chimney flange (that they chewed through) to fix the problem. BTW-they get very nasty when caged. A red squirrel years ago chewed everything in site and was downright mean. We haven’t seen any since. Meanwhile, the black squirrels don’t bother the bird feeders and seem shy and content to stay out of trouble.

  6. Thanks for that comment Rita! Very interesting, your observations about the black squirrels’ behavior re: feeders. I think there’s a lot to be learned, still, about the behavior differences in these variants. The genetics are fascinating…for example, what if the gene coding for the black fur color also has some role to play in the brain? These things are possible…so fur color might be associated with behavioral differences. Or not. We just have to observe more!

  7. Black Squirrels are at a disadvantage; except that Human Hunters pass them up. Glad to see that the crew here understands that these squirrels were imported. My understanding was that they came from China. In general the Black Squirrels seem leaner; there are other differences, and or genes, other than color. The Black squirrels did not spontaneously evolve here or in Northern Canada. Westfield was not the only place they were released.

  8. Rita, what was your black squirrel cited for (I didn’t see it in Scott Merzbach’s weekly police round up ;-)?
    My dad’s squirrely “friends” were never convicted, but he resorted to more severe punishment than allowed in Massachusetts (strange that Pennsylvania, whose state mammal is a bigger cousin to the squirrel, would allow that — but of course, they still allow it for humans too).

    Steve, next time I bike near Mt. Warner, I’ll go up for a hike and see if I can see any albino squirrels there; at WKU, there were so many that I wasn’t sure if they were truly albino or simply an unusual subspecies —
    I don’t recall those white squirrels having pink pupils (I’ll search through my photos), but it seems that eye and skin pigmentation are “genetically” independent in albinism, so white squirrels with dark pupils may still qualify…. (By the way, while I’d suspected a funny group name might exist for squirrels, given their omnipresent cohabitation with humans, I laughed out loud when I was reminded of “scurry” — the etymology should be obvious, but I’ve yet to track it down — and never had heard the term “dray” which seems to apply more commonly to a mother squirrel and her young.)

  9. Ha Rob. Yes, I caught that after hitting send…
    (May just have been from too much “citing” back in the day.)
    Meanwhile, research result findings “published in BMC Evolutionary Biology, demonstrated that the black squirrel is the product of interspecies breeding between the common gray squirrel and the fox squirrel. The black squirrel is actually a gray squirrel with a faulty pigment gene carried over from the fox squirrel that turns their fur a darker shade. (Some fox squirrels, which are usually reddish-brown, are also black.)”
    “The white squirrel is actually a genetic anomaly due to a mutated gene from the common gray. It is called leucism, a different condition than albinism.”

  10. Thanks, Rita, for the info on white squirrel genetics — and thanks for laughing together: seems some students of squirrel society agree that scurries of the shredding stealers should serve some serious time somewhere — maybe they can be put to work on little chain-gangs re-planting forests cut down for “solar-farms” — oh, that’s right: they perform that important environmental restoration anyway — three cheers for the little monsters!!! 😉

  11. The first time I saw a black squirrel was in LaCross, WI. About 20 years ago. I live in NW IN. It has only been about 4-6 years since I saw any in our area. They are still rare around here. They are so beautiful. When in WI we saw a black and gray, top half was one color the bottom half the other. It looked as if was dipped in paint.

    Lonna Temkin

  12. Thanks for that info Lonna! Super interesting about the half-n-half squirrel! I’d like to know the underlying genetics of that–although the details are probably above my pay grade. 😉

    Steve

  13. The first time I noticed black squirrels was in the Brooklyn Botanic Garden and I just assumed they were sporting the classic NYC clothing option . . . ♥︎

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