Why Did The Flying Squirrel Cross The Road?

In 2002, concerned scientists noticed that northern flying squirrels were unable to cross a stretch of scenic highway in the Unicoi Mountains of western North Carolina. This was a problem because the flying squirrels, which are declining in numbers, were unable to access foraging sites and get to others of their species for mating.

The Carolina northern flying squirrel is an endangered species that inhabits mountain forests of North Carolina, Tennessee, and Virginia. The nocturnal squirrels glide by launching themselves from a tall tree, and can typically cover distances of up to about 80 feet. But the highway, along with an adjacent treeless area on both shoulders, created a space 125 feet wide, too much distance for the squirrels to cover.

Northern Flying Squirrel Gliding

Fortunately, biologists from the North Carolina Wildlife Resource Commission and North Carolina State University came up with a creative solution to this problem, and it seems to be working. The scientists have installed three pairs of wooden poles about 46 feet high, with launching platforms at the top of each pole. The poles in each pair are situated about 49 feet apart, on each side of the road. This gives the squirrels the means to launch themselves across the highway to find food, den sites, and mates.

A Northern Flying Squirrel at a Bird Feeder

To test whether the flying squirrels were using the platforms, the research team set up cameras at the poles for a 15 month period in 2009 and 2010. During this time, they captured 14 instances of the squirrels using the poles. Here is a video showing one of these instances:





It would be nice if the success of this project could lead to similar efforts in other locations. I have written about the squirrel bridges in the town of Longview, Washington, a very successful example of helping squirrels to avoid the dangers of road crossings. Unfortunately, not every effort has been so successful. In 2010, a proposal to erect rope bridges across two highways in Arizona to help the endangered Mount Graham red squirrel was defeated by that state's legislature, due to protests from right-wing politicians who objected to the cost. Hopefully Arizona's politicians will have a change of heart before it's too late for that threatened species.