Great question. Here is a reply from the Illinois Department of Natural Resources.
Laws differ depending on the activity. Wildlife rehabilitators are allowed to return animals to the wild after they are in good health. In Illinois, Nuisance Wildlife Control Operators are allowed to relocate any species except striped skunks and raccoons. Striped skunks are a major reservoir for rabies in the Midwest, and, given the deadly nature of this disease, we do not want to take any chances on moving and releasing a skunk that is carrying the disease but not showing obvious symptoms. A study in the Chicago metro area showed that raccoons captured as nuisances in residential areas and moved to more natural habitats soon left those preserves in search of residential areas like the ones they started out in (some eventually became nuisances in the new neighborhoods where they settled). There are also concerns about moving raccoons that have diseases that can be transferred to humans, pets and other wildlife. And there are concerns about the effects of “dumping” raccoons in areas where numbers are already high, disrupting natural controls on their populations and possibly overwhelming other wildlife that raccoons like to eat. Last year, Nuisance Wildlife Control Operators captured more than 25,000 raccoons. Re-locating them might make us feel better, but it’s not the responsible thing to do given biological and practical risks associated with this activity.
