Transition zones are attractive to many mammals, so we set this camera trap up on an edge where a stand of spruce met a stand of maple. Over the next few nights we captured images of skunks, fishers, and deer, but most noteworthy was this unfortunate fox, who’s afflicted with a bad case of sarcoptic mange. He looks even more pitiful when compared to the healthy red who visited around the same time.
Mange is caused by tiny mites, Sarcoptes scabei, which are passed from animal to animal by close contact or in bedding. The mites infest the animal’s skin, and their excrement invokes an intense immune response. The poor foxes scratch and scratch, and their broken skin becomes infected. Most eventually die. You can learn more about mange in this story we published a few years back.
There’s no steadfast rule for how quickly mange spreads through a population, though common sense suggests that when populations are high, den sites get more use and there’s more fox-to-fox contact, which would mean more afflicted foxes. We’ve since gotten another picture of a different fox puppy in the same area with a bad case of mange. In our region we’ve had three good mast years in a row, and basically a year without a winter. Mouse, chipmunk, squirrel populations all seem very high, and fox populations seem to have risen with them. Mange, canine distemper, rabies, and starvation are the default ways that fox populations are managed. We’ve noticed very little hard mast on trees this summer, so if a disease isn’t already in the works in the rodent population, a lack of food this winter could lead to a correction there, too.