Northern Prairie Wildlife Research Center
Are there changes other than policy that can affect red fox and coyote distributions? The answer is maybe.
Pelt price changes have some effect on fox and coyote mortality. Generally, the higher the price, the higher the harvest, as more people are out hunting and trapping. But we don't see pelt prices as something that will alter distribution of either species for very long.
Another factor that has a greater possibility of changing distributions, at least in the short run, is disease - specifically mange.
There are several types of mange, but in North Dakota we are especially concerned about sarcoptic mange. We have been aware of sarcoptic mange, mainly in coyotes, along the Canadian border counties since 1988.
Sarcoptic mange, a skin disease caused by a species of mite (a member of the spider family) causes lesions in the dermal layers of the skin, accompanied by intense itching.These lesions open to the surface and extrude a nasty looking mess with an odor similar to dirty sweat socks. The lesions eventually cover most of the infected animal, somewhat similar to leprosy. Death is almost always the result, often from a secondary infection or possibly hypothermia or frostbite.
Until recently, mange has been fairly coyote-specific, not because the mites are specific to coyotes, but more likely because coyotes and red foxes don't have a great deal of direct contact where all the participants survive the meeting.
We have recently seen evidence that mange is spreading into the red fox population, as we expected it would. We don't know exactly how the disease will affect coyote and fox distribution; however, we do expect major changes.
We could see mange around for 15 years or so, and maybe longer, until relatively mange resistant animals repopulate vacant areas, but this is really a short time in the history of physiographic regions.