Eastern Gray Squirrels continue their phenomenal, dramatic march across the Northeast this autumn. As reported by Kent McFarland in VCE’s Field Guide to September, this species, together with its feisty relative the Red Squirrel, is appearing in droves throughout the region, apparently in response to actual or perceived food shortages. Last fall’s super-bountiful crop of cones, seeds and nuts — referred to as mast — enabled seed predators like squirrels and mice to crank out the kids. But now, with mast at “normal,” if not meager, levels across the region, there are simply far too many animals to survive in a given patch of habitat. The result? A mass and seemingly chaotic exodus, most notably of Eastern Gray Squirrels. Food is scarce, and they’re on the move.
Some more adventurous squirrels are taking to our waterways, swimming across rivers and ponds, even attempting to cross Lake Champlain. No one has witnessed anything quite like this in recent memory, though there is historic precedent, as Kent noted published reports of “great hordes” of transient squirrels back in the early and mid-1800s. This late summer and autumn, the airwaves have been rife with accounts of wayward squirrels. From birding listservs to local newspapers like the Valley News to big-city broadsheets like the Boston Globe, people are taking notice.
Sadly, what most people are noticing is less the spectacle of a stunning, living mass dispersal, but the many thousands, if not millions, of squirrels that are ending up as roadside carcasses. I recently gained some personal perspective on this. Most people know that I like to count things. I’ll confess that my latest, albeit short-term, enumeration fetish involves road-killed squirrels. I doubt I’ll ever do this again, but on a recent trip to and from southern Maine, I decided to count squirrel carcasses along my interstate route. I divided up my “census” into four sections, and here’s what I found on my two travel dates, 21 and 24 September. Nearly all animals tallied (at least those I could confidently identify) were gray squirrels.
- I-91 Hanover-Norwich to I-89 exits — 22, 15
- I-89 from W. Lebanon to I-93 — 149, 112
- Route 101 from I-93 to I-95 — 349, 455
- I-95: north side of Piscataqua bridge to Wells-Sanford exit — 114, 188
Surprisingly, there seem to be very few scavengers like American Crows or Turkey Vultures opportunistically feeding on the abundant roadkill bounty. One has to wonder if we will see a “cascading effect” through the regional food web during the months ahead, as raptors and scavengers potentially benefit (and increase in number) from a surfeit of available food, live and dead. Certainly, bird feeders are likely to host large squirrel populations this winter, to the delight of some observers and the dismay of others!
For now, the Northeast’s current mass squirrel dispersal, despite its grisly consequences along our roadways, is yet one more example of the unendingly fascinating, dynamic ecological links that characterize our natural world.