Three otherwise healthy bison were found dead in the snow in a remote Yukon valley, their bodies unmarred by any signs of a hunt, human or otherwise.
An unusual sight, for sure, but a mystery that was quickly solved by the Haines Junction conservation officer who was sent to the scene via a 40-minute helicopter ride in early February, after the bison were reported by a contractor who happened to be flying by.
Turns out, much like a winter hiker without cleated boots, bison hooves and icy, slippery slopes don’t mix too well, either.
“I had suspicions of what happened as soon as we could see the scene,” conservation officer TJ Grantham said in an interview, who went to investigate the odd discovery after it was called in Feb. 9.
“The report was just that there were some dead bison on a hillside which, in itself, is a little unusual, and we wanted to ensure they hadn’t been, you know, shot and wasted … we wanted to go in and find out what the cause of death was.”
Disembarking from the helicopter near the bodies, Grantham said he could immediately see slide marks on the side of a nearby hill, which had a build-up of ice about three centimetres thick thanks to the rain followed by freezing temperatures earlier in the winter.
“You could see the tracks, there had definitely been a herd in the area feeding up on the ridgeline, and it looked like they just started working their way down the hill face and due to the ice that was on the hill itself, it caused them to start sliding,” he said.
Unfortunately for three members of the herd, their slide ended at a cliff’s edge, followed by a fall into a clearing below.
“I mean, their path was pretty clear on the hill side, you could kind of see what had happened, so then you just want to backtrack and see where they’d been when they started,” Grantham said, adding that he was also looking out for signs like snowmobile tracks or footprints to see if human activity could have contributed to the bisons’ demise.
“Nobody had been in the area that we could tell, and you could see how slippery the hillside was and you could just piece the story together,” he said. “It just makes sense.”
Grantham said he spent about an hour on scene before determining it was the fall that had killed the three bison and that nothing suspicious had taken place. The three carcasses were left on scene.
Investigations into bison deaths are “relatively uncommon” in the Yukon, animal health unit chief veterinary officer Mary VanderKop told the News, mostly due to the fact that the animals tend to reside in areas far away from humans.
“The herd originally, when they were first in Yukon, did spend time around the roadways where there’s potential for public to be seeing them more often and there were instances then where things might be reported, but once harvest started, they located pretty quickly up into the more remote areas of the territory and particularly up into the alpine and so the possibility of them dying and being reported was much reduced,” she explained.
“Certainly in other territories, bison deaths and higher death losses of bison are much more often reported than what they are here. Northwest Territories has recurring problems with bison die-off, but that’s not something we see here.”
Generally, the most common cause of death for bison in the Yukon is predators like wolves picking off young members of a herd, VanderKop said. The unit is also aware that bison can meet their ends falling off cliffs or breaking through thin ice over bodies of water, but its not known how often those things happen because no one’s around to witness the incidents or to find the bodies.
Further hindering the reporting of bison deaths is the fact that their bodies are a prime target for scavengers and quickly taken care of, especially in the warmer months when grizzly bears are active.
VanderKop added that for her, this case is particularly interesting not just because of the rarity of the discovery, but also because of its link to a piece of history down south.
“I spend a lot of time in Alberta, southern Alberta, and Head-Smashed-In-Buffalo-Jump is located there,” she said. “It was means of harvest of the Prairie bison herd by First Nations on the Prairies, that (the herd) would be driven over the cliff and the animals that died at the bottom were all harvested. That was a mechanism of harvest there, so it’s kind of interesting that it happens by accident as well.”
Contact Jackie Hong at firstname.lastname@example.org