A collared wolf died in the wild, triggering a search and analysis. ‘It’s like CSI.’
By Scott Stowell
Special to the Star Tribune
IN THE SUPERIOR NATIONAL FOREST – Short of outlining the body at the scene, the responsibilities of wildlife biologists require an eye of a detective. Life — and death — deep in the forest can bewilder like a whodunit at the back of a dark city alley. When wilderness mysteries need explaining, enter the experts to sort out how it all went down.
Sometime in July, the radio collar of a wolf tagged No. 7263 triggered into mortality mode. The collar’s signal sounded on a telemetry receiver with rapid beeping pulses, indicating the wolf had stopped moving and could be dead.
It was time for Shannon Barber-Meyer, a research wildlife biologist for the U.S. Geological Survey in Ely, to get to work to find Wolf 7263. She is engaged in the agency’s long-running Wolf and Deer Project headed by David Mech in St. Paul, tracking collared animals of both species.
Unlike street detectives where the scene is often known before the investigation, wildlife biologists must uncover it every time. Barber-Meyer uses aerial telemetry about once per week as a way of locating collared animals and monitoring their mortality. She said aerial telemetry is faster than tracking multiple locations by land and has no road limitations. Yet, owing to a variety of circumstances in July, Barber-Meyer didn’t hear Wolf 7263’s collar in mortality mode until Aug. 2.
Searching for the canid on the ground, she used a directional antenna to locate its general area. Then she pointed an antenna toward a likely spot in the woods. The receiver beeps became louder and offered the first clue that the wolf was on that directional line. But even with that, finding it isn’t always easy.
“Wolves don’t die in convenient places,” she said.
Barber-Meyer leaned on radio signals to find Wolf 7263 in August in the Superior National Forest.
Investigating for 50-plus years
Mech, a senior research scientist with the USGS and an adjunct professor at the University of Minnesota, is one of the foremost experts on wolves in the world. He has studied wolves and their prey since 1958, and founded the International Wolf Center in Ely.
The Wolf and Deer Project began in 1964 as a long-term demographic study within Superior National Forest. Monitoring wolves and deer via radio telemetry started in 1968. Mech said it’s the longest, mainland wolf-prey study ever conducted. The study has elicited valuable information, he added, such as tracking the variations in wolf densities year to year, wolf-prey ecology, and behavior. These findings don’t happen in a year or two of study, he said. One takeaway has been the resiliency of the wolf-prey dynamic.
“Over the half-century of the study, the wolf population has survived despite drastic changes in habitat, forest management, prey populations and such diseases as canine parvovirus [parvo] and mange,” Mech said.
The project currently has eight radio-collared wolves and 13 deer. However, that’s fewer wolves than normal. Barber-Meyer said researchers will attempt to capture and collar more wolves this winter.
Project requirements include necropsy, the procedure for examining an animal carcass to determine its cause of death. Barber-Meyer, 43, said it’s similar to a human autopsy only the checklist of causes is more basic.
“It’s like ‘CSI,’ only we don’t use all the tools they would,” she said. “They have unlimited budget.”
In 2017, researchers gathered data from necropsies on eight wolves and five deer.
On the ground
The plot thickened before Barber-Meyer entering the bush to try to find Wolf 7263.
For some reason, the radio signal re-entered active mode, indicating the collar had moved. Barber-Meyer was unfazed. She said misleading information can pose as solid evidence. Though exceedingly rare, the collar may have malfunctioned. It could also have been kicked by another animal.
However, this situation came with a twist. In her experience, reactivated collars were normally on deer caused by wolves tugging at the carcass. “But this is on a wolf,” she said. “So, it’s a little more interesting.”
She also had an accomplice. A turkey vulture flew above the road near where the radio signals had become strongest. She guessed it was looking to feed on the wolf.
Barber-Meyer’s nose helped, too. Deeper into the woods, she began smelling the decay of an animal. Shortly thereafter, she found Wolf 7263 dead on the ground.
When approaching any carcass, Barber-Meyer takes photos before disturbing the scene. She also inspects the area to determine if the animal died naturally or from human causes.
“Once you get in there and mess it up, you can never go back,” she said.
Broken vegetation, blood trails and scattered remains can indicate a fight. She said an animal’s body position also offers clues. If it’s curled up, it may have starved to death or perished from disease. Other times, it may appear to have fallen instantly on its side as if it was shot.
For Wolf 7263, a female, Barber-Meyer performed the entire necropsy in the field. She only brings out carcasses if they’re fresh, intact, and might be used for education. However, Wolf 7263 had begun to decompose. Barber-Meyer couldn’t check her weight, find superficial skin wounds, blocked intestines and a variety of other pertinent information or abnormalities. But the researcher was intent on giving the wolf due diligence.
Barber-Meyer said there weren’t apparent signs of a tussle with other animals. A hole in the female wolf’s ribs looked to be postmortem, like an avian scavenger pecked it, rather than, say, an entry wound from a bullet. No broken bones were discovered, and its deteriorating fur showed no road rash. However, roadkill was still a possibility; there could have been undetectable internal bleeding. Then upon examining the collar, she discovered the trachea pulled to the side.
“That’s probably what caused the collar to go on active mode,” she said. “Maybe the vulture, but who knows?”
With wildlife, death isn’t always criminal and the perp is often the harsh realities of nature. Barber-Meyer said with so much inconclusive evidence, a cause of the demise of Wolf 7263 was tricky.
She ruled out mange because the wolf’s entire underside was furry and there were no obvious signs of disease. It also could have starved. But having died 200 feet from a road might indicate human causes.
“My best guess would be that maybe it was clipped by a car,” Barber-Meyer said. “But the way I’ve categorized it for the [record] is ‘unknown.’ I can’t even categorize it as natural or human cause.”
Upon leaving the scene, she pondered mysteries in the wild and how people often drive down dirt roads without second thoughts. Even biologists get only a glimpse.
“What else is all around here that we have no idea about?” she asked.