Paul A. Smith Milwaukee Journal Sentinel
Gray wolves have long been known to possess deep reserves of stamina, typically used to pursue and take down prey.
But that physical asset can also allow for long-range travel.
How far? Thousands of miles, according to several studies in the U.S. and Europe.
Modern technology — especially GPS tracking devices — is increasingly allowing scientists insight into the movements of all animals, including wolves and other large carnivores.
Case in point: an adult male wolf fitted with a GPS collar earlier this year in the Upper Peninsula of Michigan.
The animal was captured in an offset jaw trap Jan. 30 by a recreational trapper. Because wolves are currently protected in the Upper Midwest under the federal Endangered Species Act, the trapper had to release the animal.
The trap design, used by researchers as well as recreational trappers, allows animals to be released uninjured.
Rather than just let the animal go, the trapper called the Michigan Department of Natural Resources, which routinely communicates its desire to place GPS collars on wolves and other non-target species captured incidentally by trappers. The agency immediately dispatched a biologist to the site.
The wolf was fitted with a GPS collar and released. The animal was estimated at 85 pounds in weight and in good condition, according to Cody Norton, MDNR large carnivore specialist.
The data provided by the GPS collar over the coming months provide a fascinating tale of the distances and habitat preferred for dispersing wolves in the Upper Midwest.
The GPS device provided locations to the MDNR every two hours, Norton said.
The adult male wolf stayed in and around Mackinac County, Michigan, for about six weeks after it was collared; from Jan. 30-March 15 it covered 81 miles.
Then it decided to set out beyond the horizon.
It moved southwesterly and crossed the Menominee River into Wisconsin, traveling west of Marinette, Green Bay and Appleton before heading more westerly across the Badger State.
It negotiated the concrete ribbons and potential traffic hazards of I-39 and I-94 then turned south toward La Crosse, before reversing course and heading northwesterly.
On April 15 it was captured on a trail camera near Arcadia in Trempealeau County.
The trail cam time stamp and GPS data match perfectly, Norton said. In addition, the wolf had unique coloring that allowed the individual to be identified.Get the Coronavirus Watch newsletter in your inbox.
From there the wolf continued toward Hudson, where it again survived I-94 and crossed the St. Croix River into Minnesota.
Norton said the wolf crossed the Mississippi River just north of Little Falls, Minnesota.
It then trekked across Minnesota, made a brief foray into North Dakota and moved north into Manitoba.
The international border, it must be noted, was closed to human traffic due to the coronavirus pandemic.
As has often been stated by scientists, wildlife does not recognize geopolitical boundaries.
After venturing nearly to Winnipeg, the wolf turned south and re-entered Minnesota.
Sadly, it was illegally killed Aug. 2. Norton said his agency received a mortality signal from the GPS collar and contacted the Minnesota Department of Natural Resources.
Minnesota DNR law enforcement officials recovered the animal and are working on the case.
After the animal dispersed from the U.P. of Michigan, it covered a minimum of 1,973 miles, Norton said.
Since the signal was only received every two hours, the total distance the wolf traveled is unknown but in all likelihood greater that the minimum documented by the GPS logger.
Why do wolves move such distances?
Dave Mech, a world-renowned wolf researcher with the U.S. Geological Survey and University of Minnesota, said wolves typically leave the security of their natal area to find mates and a new territory.
The movement helps the gene pool by increasing the odds of finding an unrelated mate. It also helps wolves, which were targeted in extermination programs until the 1960s in much of North America, re-establish packs in historical regions.
Although the topic has been fairly well researched, in a paper published June 1 in Mammal Review, Mech addresses three movement patterns of some natal-dispersing wolves that remain unexplained: long-distance dispersal when potential mates seem nearby, round-trip travels from their natal packs for varying periods and distances and coincidental dispersal by individual wolves.
Would the 2,000 miles covered by the male wolf from the U.P. be a record movement for a wolf dispersal?
Not according to several wolf experts and studies.
A young female wolf in northern Europe traveled an estimated 6,200 miles from southern Norway to northeastern Finland, close to the border with Russia, over the period of June 2003 to March 2005, according to a paper published in 2007 in the Journal of Wildlife Management.
The European researchers later also recorded a similarly-long dispersal from a male wolf born in southeastern Norway in 2012 that traveled to northern Karelia in Russia.
Closer to home, a 2000 paper by Samuel B. Merrill titled “Details of Extensive Movements by Minnesota Wolves” cited one case of a wolf that traveled a minimum of 2,641 miles.
Where was the Michigan wolf headed when it was illegally killed in Minnesota? Was it, for example, heading back to the area it was born in the U.P.?
Such questions will never be answered.
But Norton said the GPS technology does provide wildlife managers with a treasure-trove of information, including the travel routes preferred by dispersing carnivores.
In many cases, riparian — or river — corridors are key for animals on the move.
As an example, Norton said when mountain lions disperse easterly from the Dakotas, they most often follow rivers. Then when the animals hit the forests of Minnesota they “blow out” in several directions, no longer confined to the riparian cover.
As human development continues apace into the future, data provided by animals such as the Michigan wolf could allow wildlife managers to protect critical habitat linking discrete groups of animals.
In so doing, the researchers can parlay the life histories of the animals, offered in high resolution by modern technology, from a fascinating travel tale into tangible programs to sustain the species.