On the outskirts of Keokuk, a city in Iowa鈥檚 southeastern tip, Dave Hoffman descends into a brushy, wooded ravine to check a trail camera.
It鈥檚 mounted low on a tree, pointing straight at a half-buried, four-inch black plastic drainage pipe. This unassuming hole in the forest floor also happens to be one of the den sites of a gray fox 鈥� a secretive and exceedingly rare species in the state.
Walking along a cedar thicket, the wildlife technician with the Iowa Department of Natural Resources points out bird droppings and other animal signs.
鈥淚 was seeing lots of feathers here a couple of weeks ago on the snow,鈥� Hoffman said. 鈥淭his gray fox can climb these trees and actually get some of these birds roosted in some of these trees here.鈥�
Gray foxes are canines in the world known to climb trees; their and help them scoot up trunks to hunt and escape predators. The unique canine can be found throughout nearly all of the U.S., north into the eastern edges of Canada and south through Central America and the northern part of South America.
Yet their numbers have steadily dropped in several Midwestern states. In Iowa, for instance, historic and wildlife observation surveys conducted by DNR staff and volunteers indicate a steady, downward trend over the last 25 years.
鈥淚t鈥檚 to the point now that it鈥檚 a pretty big concern because the population is so low that we鈥檙e at risk of losing this wildlife species out there,鈥� said Vince Evelsizer, an Iowa DNR furbearer biologist. 鈥淎nd on top of that, there really isn鈥檛 very much research that has been done about the gray fox in the Midwest.鈥�
Wildlife biologists from Illinois, Indiana and Ohio have noticed a similar decline and are looking for answers. Now researchers at state agencies in all four states are conducting studies, hoping to share what they learn to better understand regional trends.
Leading the way
Indiana was the first of the four states to launch a gray fox study, .
Geriann Albers, Indiana DNR鈥檚 furbearer and turkey program leader, said people were noticing fewer gray foxes in certain parts of the state
鈥淲e were hearing some concern from the public, especially from licensed trappers, that they weren鈥檛 seeing them anymore where they used to, and that spurred us to start looking into and put some funding toward this big research project to find out what was going on,鈥� Albers said.
Indiana partnered with the nonprofit Wildlife Ecology Institute to gather and analyze field data from two multi-county study sites 鈥� a highly forested area along the southern border with Kentucky and a more agricultural area farther north.
With the help of local trappers and trail cameras, they captured, radio-collared and released 28 gray foxes, most of which were in the southern site.
Dawn Reding, a wildlife geneticist and associate professor of biology at Luther College in Iowa, is leading the lab work. To understand the prevalence of certain diseases, Reding tests blood samples for bacteria and viruses, and antibodies, which indicate the fox鈥檚 immune response to recent or past infection. She鈥檚 also looking for environmental toxins in the blood, like lead and rodenticides.
By analyzing DNA, Reding is learning more about the gray foxes鈥� genetic diversity and diet. This includes samples from animals that were killed by vehicles or died over the course of the project.
鈥淲hen I see a carcass, I see gold,鈥� said Reding. 鈥淎ll the different pieces of information that you can gather from that carcass is amazing in terms of genetic material.鈥�
That information may help researchers determine what鈥檚 behind the decline in gray foxes 鈥� and address it.
As Indiana's gray fox study wraps up later this year, Albers says the DNR can use the research findings to make recommendations, whether for new regulations or population re-introduction.
鈥淲e can evaluate all of those things once we have this data to help us inform those decisions to figure out what tool is the right tool for the job or what suite of tools are the right tools for the job,鈥� she said.
Possible causes of decline
While , , and have hunting and trapping seasons for gray foxes, it鈥檚 unlikely that these activities are the largest threat to the species, at least in Iowa, according to Evelsizer.
The DNR conducted a fur harvester effort survey from 2018 to 2021 with a subset of predator hunters and trappers. Participants kept track of what they caught in a season and what they were targeting.
鈥淟ess than 1% of the fur harvesters targeted gray fox. I think the importance of that is that while their numbers are low, we do not feel that trappers are driving their population down,鈥� Evelsizer said.
According to the DNR鈥檚 鈥溾�� logbook, one gray fox was harvested during the 2021-2022 season compared to an all time high of 3,093 during the 1979-1980 season.
Evelsizer says factors that may play a bigger role in the decline of gray foxes are habitat loss, disease and competition with other wildlife. have documented coyotes and bobcats harassing and killing gray foxes in or near their territories.
While there鈥檚 still a lot of data to dig into with the Indiana project, Reding said one of the causes for the decline in gray foxes may be a highly contagious disease.
鈥淐anine distemper virus seems to be a major source of mortality for gray foxes in our study area, and this is important: they鈥檙e not the only species that can get canine distemper virus,鈥� said Reding.
Infected coyotes, racoons, skunks and unvaccinated dogs and cats shed the virus through respiratory droplets, saliva, urine and feces. Feeding from the same carcass or pet food bowl, grooming or simply coughing in the vicinity of another animal can quickly spread the disease between individuals and across different species.
The Midwest has a big population of racoons that may be serving as a reservoir of distemper, according to Tim Hiller, the founder and executive director of Wildlife Ecology.
鈥淲e have a video of a gray fox den and very close interactions with racoons that were harassing that gray fox,鈥� Hiller said. 鈥淪o, undoubtedly, the question may be at what level these two species are interacting 鈥� not whether they鈥檙e interacting.鈥�
A 2022 from North Carolina State University highlights how tree cover may affect another interspecies interaction.
While gray and red foxes are native to North Carolina, coyotes arrived within the last . The study鈥檚 lead author, Arielle Parsons, says the timing offered a unique opportunity to track potential impacts on foxes. Specifically, the researchers wanted to know if coyotes and foxes were using the same habitat and at the same time.
Over 300 trained citizen scientists helped set up camera traps along the urban, suburban and rural gradient around Raleigh. Among the findings, gray foxes in rural areas used the same sites as coyotes, at roughly the same time 鈥� if there was enough tree cover. Without it, gray foxes avoided areas that had recently been used by coyotes or shifted to being active later at night.
Parsons said this suggests that gray foxes are climbing trees to temporarily avoid coyotes.
鈥淚 do think that what is happening in North Carolina and kind of this result of the tree cover can be extended to the Midwest,鈥� Parsons said.
She sees it as a hypothesis that could help researchers determine what is happening to gray fox populations.
鈥淏ecause we鈥檙e all seeing indications that coyotes are playing a role,鈥� she said, 鈥渂ut clearly habitat is an important factor, and likely there鈥檚 an important interaction between the two.鈥�
Volunteers help in Iowa
In Iowa, DNR officials asked for the public鈥檚 help to find, and even capture, live gray foxes for its pilot study.
Evelsizer said he鈥檚 been 鈥減leasantly surprised at the amount of public support and interest.鈥� People have shared trail camera photos and sightings from around the state.
Then last November, Evelsizer and Hoffman received a call from a trapper near Keokuk who had captured a 10-pound male. They traveled with the state wildlife vet to put a tracking collar on the fox, called GF1, as well as take measurements and a blood sample.
"We released him and he took off and he stayed in the area,鈥� said Hoffman. 鈥淗e seems to be doing really well.鈥�
Now Hoffman is able to use an antenna and radio receiver to narrow down GF1鈥檚 location. Once he鈥檚 within range, he can then connect with the gray fox鈥檚 GPS collar and download all of the fox鈥檚 movement data.
鈥淭his will tell us about his den sites and the habitat that he鈥檚 using here,鈥� said Hoffman, flipping open a laptop to reveal an aerial map and a web of green lines.
Since Hoffman is based over four hours away from Keokuk, he said he relies on 鈥渁 small army of volunteers鈥� to help collect data on GF1. One of them, Harry Brackenbury, drives up to Hoffman鈥檚 parked truck to discuss GF1鈥檚 latest movement data.
Brackenbury checks the fox鈥檚 tracking signal several times a day and records weather conditions.
鈥淏eing an avid outdoorsmen and hunter myself, it鈥檚 not all about the taking of an animal all the time. It鈥檚 preservation,鈥� said Brackenbury.
So far, GF1 is the only gray fox the Iowa DNR has caught for the project, but the researchers hope to collar more in the coming years to learn about the canine鈥檚 habitat use and range, behaviors, genetic diversity 鈥� and what鈥檚 behind their decline.
This story was produced in partnership with a collaboration of public media newsrooms in the Midwest. It reports on food systems, agriculture and rural issues.
