Back Up and Running, and What's Up with all the Roadkill Squirrels?

Hello all,

It has been a bit since my last post but I am planning on getting back to my regular ways this year with a little twist. I will be keeping readers up to date on all of the happenings in the T.A. Forest as usual but am hoping to expand my posts to some of the big things going on with the T.A. Anglers' Society as well as my personal adventures afield in Maine throughout the year.

This fall marks the fourth year of the T.A. Squirrel Project in which my Maine Fish and Wildlife students assist in trapping and collaring gray squirrels (Sciurus carolinensis) around campus then monitor the population using trail cameras in the late fall/winter. Wildlife-minded folks around the state have been noting a big uptick in roadkill squirrels this season. It has been featured recently on local news outlets and the Portland Press Herald. Doug Hitchcox (@dhitchcox), a former classmate of mine and current staff naturalist at Maine Audubon, observed 311 roadkill squirrels on I-295/95 north/south in a 293 mile round trip on Tuesday. That level of road mortality is unheard of in a normal year here in Maine. There are multiple factors coming together to create this perfect storm. First, two years in a row of large acorn crops have allowed high reproductive success, or recruitment, in our local squirrels. Second, this time of year the squirrels' second batch of offspring are beginning to strike out onto the landscape naive to many dangers including road crossing. Finally, add in a fall with notably fewer acorns hitting the ground and you have a booming population forced to move around the landscape more in search of food.

A collared squirrel hit on Fairfield Street adjacent to campus last winter. 

Irruptions, or marked increases in the occurrence of a species, happen naturally, most commonly with migratory birds. Snowy Owl populations in the arctic are cyclical and are tied closely to recurring rises in lemming numbers. When lemming populations are high, snowy owl recruitment ramps up leading to irruptions of young owls here in Maine during the following winter as lemming numbers begin to decline and individuals strike out in search of food. Squirrel irruptions have been documented occasionally around the country since the 1700s. Famed naturalist, James Audubon, presumed that the "migratory" squirrels he observed during a particularly large irruption in the mid 1800s must have been an entirely separate species. He named it Sciurus migratorius. It turns out they were just eastern gray squirrels and he was one of the earliest observers of a natural boom and bust cycle in a species tied closely to tree nut production. So keep your eyes peeled for squirrels in the road and do your best to give them a break. We are lucky not to have to dodge vehicles to grab breakfast.