IWF Partners with Iowa DNR on Gray Fox Study

It was Mid-May, and spring birding was at its peak.  With sunrise still a half hour in the offing, I was standing in a narrow strip of public timber extending from the western edge of Clear Lake’s Lekwa Marsh.  Although the predawn light was dim, the woodland was already bursting with song.  In addition to camera and binoculars, I also carry a turkey call on spring outings.  Always fun to elicit a gobble or have a nearby hen answer my yelps.

Leaning against a large maple, I sounded a few calls and waited.  No turkeys responded, but almost immediately I detected the movement of an animal moving down a trail in my direction.  Low to the ground, the predator was ‘traveling on its belly’ and moving fast.  The body language was unmistakable.  This animal was on the hunt.

At first, I thought it was a large tom cat.  But as it continued to draw closer, I could see that it was a fox.  Not especially unusual since the region currently hosts a large and healthy population of red fox.  I see them all the time.  The animal continued to move closer until, by the time it had come to a distance of just 15 or 20 feet, I could suddenly see that it wasn’t a red at all but instead was a beautiful gray fox – a species that unfortunately has become one of Iowa’s rarest mammals.

Suddenly sensing that something was amiss, the approaching gray hit the brakes and became a crouched statue.  The wind was in my favor, and the fox began bobbing its head in an effort to determine exactly who or what I was.  As its suspicion grew, the fox suddenly rose to its feet and then quickly disappeared into the newly emerged spring foliage.

Memory can be inaccurate, but I think that this was the first gray fox I had seen in 15 years – maybe longer.  In days gone by, I would spot grays on a semi-frequent basis while bow hunting from tree stands or driving gravel roadways.  I would also spot their tracks atop snowy woodland blowdowns.  Where I live near the south shore of Clear Lake, there was an active den just fifty yards from my house.  Another den was located under a barn less than a mile away.  But that was in the late 1980s.  The fox are gone and those dens are now occupied by woodchucks.

The close up, nearly face to face, gray fox encounter described above took place four years ago.  I have not seen, or even heard of another since.  Not surprising, really.  During recent decades, the gray fox has gone from somewhat common, to rare, to an unofficially endangered species.

To better understand – and hopefully reverse — the fox’s alarming spiral, DNR biologists began a gray fox research project in 2022.  One of the study’s primary objectives was to equip [cage trapped] fox with tracking collars.  Once installed, the collars would allow biologists to remotely monitor fox activities without further human contact.

“One of our major objectives for the collaring program was to identify specific causes of fox mortality,” says DNR Furbearer Resource and Wetland Specialist, Vince Evelsizer.  “We also wanted to determine what effect diseases – particularly canine distemper – might be having on the species.  Through the use of tracking collars, we also hoped to identify specific habitat use and determine home range.”

But obtaining live specimens of a rare species for study has been an uphill struggle.  So challenging, in fact, that no gray fox were captured during the study’s first year.  During the project’s second year [2023], only one fox – a male — was successfully captured and collared.  Although an additional pair of gray fox was located at Mason City, the animals repeatedly eluded capture.  In mid-May, the [nursing] female was killed in a tragic accident.  The male was never seen again.  Although Evilsizer conducted an extensive search for the den and its pups, the site was never located. 

“By now it was clear that Iowa’s gray fox population had declined drastically,” said Evelsizer.  “Numbers have apparently become so low that the male we collared in 2023 did not find a female to mate with during the entire breeding season.  For me, that was a red alert.” 

“At this point we began asking the public for help – first person sightings, reporting discovered fox carcasses, trail ‘cam photos — anything and everything that would add to our data.” 

“We also gained a valuable partner when the Iowa Wildlife Federation stepped up and offered a $400 reward for anyone who could capture a live [gray] fox,” said Evelsizer.  “There was no red tape, and if a fox was captured, a check could be cut on the spot.  That was a wonderful incentive for someone to try and catch a fox.”

That incentive proved to be worth the money when an Amish trapper reported that he had captured a second gray fox in southern Iowa last Monday.

“The fox was caught in a snare and was totally unharmed,” said Evelsizer.  “The trapper had heard about the reward being offered by the Iowa Wildlife Federation and called us right away.  Despite being bitten in the hand, he did his best to keep the animal calm and safe.”

Next on the scene was DNR Conservation Officer, Bob Stuchel who successfully transferred the fox to a safe holding cage.  Once researchers obtained weight, measurements, and blood samples, the fox – this time a female — was fitted with an activated tracking collar and released at the capture site.  

“There is much more we hope to learn about gray fox and most likely there are a variety of factors leading to their decline in Iowa,” says Evelsizer.  “It’s likely that things like ongoing habitat loss, competition with other predators, and disease are all playing a role.”

Historically, gray fox were found around old farmsteads, brush piles, brushy fencerows, and woodlands containing thick understory.  Today, many of those habitats have been eliminated.  Farmsteads have been removed, maturing woodlands have become more open, fencelines have disappeared, brush piles burned.

“Gray fox also face competition from larger predators, even raccoons,” said Evelsizer.  “We already know that gray fox and raccoons are in direct competition for denning and daytime resting spots.  A raccoon can weigh up to 35 pounds, while a mature gray fox will only weigh ten to twelve pounds.  It doesn’t take much imagination to guess who will win that contest.”

Disease is an additional concern.  Gray fox – much more so than their close cousin the red fox – are genetically predisposed to contracting canine distemper.  The incidence of distemper has shown a steady increase over the past thirty years.  As the number of potentially infected raccoons has soared, the number of gray fox has waned.  Coincidence?  Maybe.  Maybe not.

“The fact that only two fox have been successfully collared in three years of study shows just how few are left out there”, notes Evelsizer.  “For the first time since record keeping began in 1930, there were no gray fox pelts reported during Iowa’s 2023 fur harvesting season.  Only single digits were reported for gray fox during the preceding six years.”

DNR researchers are currently expanding Iowa’s gray fox study with the launch of a pilot ‘camera trap survey’ across four counties in northeastern Iowa.  The survey is conducted by placing movement triggered cameras in line with suet feeders baited with meat and doused with salmon oil.  In addition to gray fox, the survey routes will also record the number of raccoons, red fox, coyotes, and fishers visiting the bait sites.