Iowa DNR research project: tracking gray fox

DES MOINES — Experts in the Iowa Department of Natural Resources are asking Iowans, including trappers, for help in research that may explain why there are a dwindling number of gray fox in Iowa.

Vince Evelsizer, a furbearer biologist at the DNR, says gray fox are pretty secretive, not very vocal and live primarily in wooded areas of eastern and southern Iowa. “For the past 25 years or so their population trend has been downward, however we don’t know a whole lot about the gray fox. We know much more about the red fox than we do the gray fox,” Evelsizer says. “…Our ‘guess-timate’ is that there would be 10-20% of the gray fox out there that there used to be and that might be a generous estimate.”

The DNR is offering $400 to trappers who catch a gray fox in a cage and turn the live, healthy animal over for the DNR’s research project, so it can be fitted with a neck collar that has a tracking device. Evelsizer says Iowans who are certain they know where gray fox may be in their area can call the agency, because he and another staffer who’re working on the project might be able to catch the fox and put a GPS collar on it.

“Also if they find a fresh dead gray fox this fall and winter, we’d even like to have that for study as well. We can look at the health of that dead gray fox as far as what kind of shape was it in, what was the reason it died,” Evelsizer says, “so live foxes and dead foxes are helpful for our study.”

The DNR conducted a survey between 2018 to 2021 and found “next to zero” gray fox had been trapped in Iowa, according to Evelsizer, so it’s unlikely the population decline is because they’re being captured for their fur. “What we think the likely causes are for their population decline are other things such as disease, changes to habitat and competition with other predators such as coyotes and bobcats,” Evelsizer says, “and even domestic dogs, too.”

The state of Indiana has a similar project to track gray fox there. Evelsizer says the gray fox population is declining steadily in Midwestern states.”However, in the southeastern U.S., the gray fox population is doing fine and then, also of interest, the gray fox are doing pretty well in the northern half of Minnesota,” Evelsizer says. “Why are they not doing well in the Midwest? We have some ideas, but we’d like to figure it out and get the answers through research so that we have a science based approach to it…knowing whether or not there are any kind of solutions we can implement.”

Gray fox are native to Iowa. An adult gray fox typically weighs between 10 and 12 pounds