New research on how far deer travel each year may help state wildlife managers predict how far and fast Chronic Wasting Disease will spread. The results of tracking 80 radio-collared deer in the CWD hot zone this year found most adult does and bucks stay within one square mile. Young bucks travel about five miles from their birthplace. Researchers say that means the CWD hot zone could expand by about five miles a year.

But the research by University of Wisconsin wildlife ecologist Nancy Mathews also found a few young females make long exploratory round trips. In one case, a young doe walked more than a hundred miles from Mount Horeb to Freeport, Illinois and back. Mathews says that kind of movement could spread the disease further. She says if these deer are infected, then the potential for the spread of the disease is as far as these deer actually move. However, it’s not known whether the wayward deer in the study are infected. Scientists still aren’t sure whether CWD is spread by saliva, urine, feces or infected soil.

Mathews says her research also shows a significant number of deer are staying on land owned by people who oppose the state’s efforts to fight the disease by drastically reducing the deer herd. She says ultimately, if this pattern continues, the deer that remain on the landscape will be on land that is not being harvested as intensively and by default they become refuges. Mathews says such refuges could become safe harbors for infected deer making it more difficult to eradicate the disease.