Radio collared wolf that left Isle Royale by way of ice bridge makes incredible journey
The 4-year-old, 30 kg female known as W003F logged thousands of kms in Minnesota and Ontario
In January 2019, the Polar Vortex arrived across much of the northern United States and Canada and Lake Superior began icing over between Isle Royale, on the Michigan side of Lake Superior and the Ontario coast.
A rare ice bridge formed and for a recently re-located wolf made her escape off Isle Royale.
Wolf 003 F — a four-year-old, 30 kilogram female originally live trapped and radio collared on the Grand Portage Reservation in Minnesota — made her move.
On Jan. 31, 2019, W003F removed herself from the world's longest running predator-prey study.
The wolf crossed the 30 kilometre ice bridge and left the island she had been brought to by the National Park Service just four months earlier.
Beth Orning is the lead author of a research paper, recently published in the Northeastern Naturalist, which tracks W003F's incredible journey.
Orning said W003F had been brought to the island in October 2018 to kill moose and breed, but that was not how it turned out.
Whether it was a high female to male ratio or just an urge to go back to the mainland, W003F chose not to hang around.
Of the nearly 20 wolves captured and brought to the island to resurrect the wolf packs, W003F has been the only wolf to use an ice bridge as a means of escape.
Ironically, it is thought ice bridges were responsible for the arrival of wolves on Isle Royale in the 1940s.
Orning said it was a bit of a surprise that W003F left the island, since there was no shortage of food. However, she said many factors can come in to play.
"Being a new animal to the island, wolves that are introduced into a situation like that are essentially put into a dispersal state," Orning said."Which basically means that they don't have local knowledge of food resources, and so, while there was a lot of moose, it's also a challenge to take down a moose as a single wolf."
Orning said in 2018, the National Park Service began capturing wolves on the mainland, in Minnesota, Ontario and Michigan and then releasing them on the island.
This was to add new genetics to the existing wolf population on Isle Royale.
That wolf population had been shrinking since 2006 and a rapidly growing moose population threatened to overrun the island if unchecked.
Orning said initially W003F moved back to an area within 20 to 30 km. of where she had been captured, but then she got moving.
Because W003F was wearing a tracking collar, researchers could keep track of her location and movements by satellite. Orning said W003F ended up spending the next year wandering the region, crossing the international border at least twice and logging thousands of kilometres in the process.
"She continued traveling around Minnesota and into Ontario, until deciding to remain there from July to September 2019," Orning said. "From September to October 2019, W003F ventured back to Grand Portage Reservation for a month. Although she has spent most of her time in Ontario since October 2019, she did make two excursions to Voyageurs National Park in Minnesota during February and March 2020."
At the end of 2020, the GPS portion of the radio collar died and quit transmitting. Orning said at that time W003F had been spending most of her time northwest of Thunder Bay.
Although the collar does have a VHF frequency that will only last for another year, Orning said no one is sure where W003F is now.
"The collars have a secondary beacon you can hear from an airplane or even from the ground," she said." So we're hoping that maybe some local biologist will have some additional information for us at some point in the future."
Orning said that during her recorded travels W003F covered nearly 1.5 times the daily distance of her counterparts back on the Isle Royale. Yet Orning said even that does not make W003F super unusual in the wolf world.
"They certainly can and do make these kinds of long-distance movements and can spend upwards of two years moving around," said Orning. "Which is what she did after she was released. But it's also not the most common thing. So it's not completely normal. She's a little bit of a rare wolf."