Just before the snow on 12 March, I took this photograph of an American Red Squirrel, Tamiasciurus hudsonicus. Red squirrels are found across much of northern North America, venturing further south through the Appalachian and Rocky mountains. Red Squirrels are common and their range is expanding in our region. Although their diet specializes on conifer cones, the species has moved into deciduous forest, and even into prairies of southwestern Minnesota.
As I explored the Internet for something new to write about American Red Squirrels, I discovered an article by Ed Yong in the November 2016 issue of The Atlantic. I discovered that Eurasian Red Squirrels carry leprosy. I thought that armadillos are the only animals aside from humans to carry this disease. Armadillos got leprosy from European human explorers to the New World. Much of the world’s leprosy research takes place in Louisiana, where armadillos are abundant.
Luckily for our red squirrels, the European squirrels do not overlap with ours—and the two squirrels are not closely related. Eurasian Red Squirrels, Sciurus vulgaris, are in a different genus than ours. Armadillos can pass Leprosy back to humans, Although Eurasian Red Squirrels carry the same strains of Leprosy that infected medieval Europeans, there is no evidence of their passing the disease to humans.
Although once common, Eurasian Red Squirrels are endangered in Britain. Gray Squirrels, introduced from North America, have outcompeted them. The remnants of the British red squirrels are now mostly found in Scotland. Gray Squirrels also carry squirrel pox, a viral, tumor-producing disease that often kills the red squirrels. Squirrel Pox is also found in eastern North America, but here many infected squirrels survive the disease (Michigan DNR).