The parking lot at work is lined with big old oak trees, and this time of year they are dumping thousands of acorns. In fact, every time there’s the least breeze you hear so many falling it might as well be a hail storm. (This is in the Boston area, btw.)
Normally the neighborhood squirrels do their best and pretty much keep up with the bounty. In fact, if you sit quietly in your car, you are likely to see at least a dozen squirrels at a time frisking about the lot.
This year – well, the paved area is almost solidly covered in acorns. It’s at the point where it is dangerous to walk if you have any heels at all, and even in flats your foot tends to slide a bit before your weight starts smashing the acorns. Crunch, crunch, crunch.
Since I noticed the acorns accumulating a few weeks back I’ve kept a special look out, and I have not seen a single squirrel! Not in that lot, not in my own yard, not anywhere. People I’ve mentioned the dearth of squirrels to tend to think a moment, then say they can’t remember when they last saw a squirrel.
Where have all the squirrels gone? There are a few coyotes known to live in the town, and a couple of fisher cats have been spotted. Could a handful of predators account for such a change? (Or maybe aliens have moved on from abducting humans?)
There are tons of chipmunks about, many more than usual. Is that related? Though if it’s predation, wouldn’t coyotes etc. be just as happy to munch on Chip and Dale?
Populations of many species are often cyclic, with periods of boom and periods of bust.
Squirrels are susceptible to a number of diseases such as Squirrel Pox and Squirrel Fibroma. Both of these have significant morbidity and mortality, are contagious by contact, and therefore tend to run swiftly through localized high density populations. After an outbreak the local population will be reduced in numbers, sometimes substantially reduced. Lower population numbers mean lessened contact between individuals, mitigating further spread of the disease. Resistant (or just plain lucky) survivors will rebuild the population over the next year or several, making use of the additional resources now available because of lessened exploitation. After some (usually variable) period, numbers will once again become high. High population density means that any new disease outbreak will be rapidly transmitted throughout the population. Lather, rinse, repeat. Cyclic population dynamics 101.
They’re certainly here in South Carolina. Yet another year where I didn’t get to eat a single pecan. (The first year I moved into this house we had a hawk and no squirrels. The hawk moved out and the squirrels moved in, so no pecan crop. Maybe you have a hawk.)
Judging by the number of baby squirrels that have fallen out of trees that people bring to us, they are doing quite well. I don’t know how the next generation will fare, though.
There are plenty of gray squirrels around here in Connecticut, but there were reports last year of limited acorn production in some areas. Fewer acorns last year, fewer squirrels to eat acorns this year. I had the impression that the acorn drought was limited to points south, though, and we had plenty around here.
I too am in CT. I noticed a couple of squirrels in my backyard the other day. One weird thing I noticed this year the acorns falling from my trees are tiny, really tiny about 1/2 the size of previous years.
our reds and grays are fine. but we’re real low on rabbits compared to 2+ years ago. but this spring we had bumper crop of baby bunnies. and so it goes.
NJ resident here: I believe that last year there was an acorn crash in the eastern US, oaks over large areas have been known to have cyclical ‘low acorn production years’. Last fall/winter everyone here was talking about the starving squirrels. http://www.stoweboyd.com/ground/2008/11/acorn-crop-cras.html
In a biology class some years ago I remember learning that it could possibly be a tree response to predation, a low year kills many squirrels, leaving many nuts around the next season. Don’t have any kind of cite for that, though.
I also have not seen the usual number of squirrels this summer, and last fall we had very desperate squirrels in our yard eating all of the pumpkins out as decorations. Hadn’t seen that before.
I used to keep (“own” isn’t the right word) a cat with a penchant for squirrels. All I ever found were tails. It’s amazing how thorough a hungry cat can be.
I attribute it to the resurgence of the falcon population in NJ. My yard used to be lousy with them. Then several years ago I was looking out my kitchen window and actually saw a falcon swoop down and snatch one right off the ground. It carried it to a log in a more deserted part toward the back of the yard and proceeded to chow down.
I don’t think I had really noticed prior to that but afterwards I notice that there didn’t seem to be nearly as many squirrels around. Now, on any given day when I look out my window, I almost never see one when maybe 5 years or so ago that would have been unthinkable.