Yukon species list shows climate change in action

When asked how biodiversity is changing in the North, Yukon botanist Bruce Bennett has a ready answer — "rapidly."

"Things are happening so rapidly and we are at the forefront, especially of species' range expansions," he said.

Bennett spent the weekend in Whitehorse at a biodiversity forum talking with botanists, biologists and other people who study and track northern species. The forum is an annual gathering, where Yukon researchers share their work.

A big emphasis in the last few years has been updating and adding to the list of species known to occur in Yukon, which is maintained by the Yukon Conservation Data Centre ("kind of like a library on biodiversity," Bennett says.)

This past year, a whopping 1,973 species of plants, insects and animals have been added. Some of it is simply catch-up work — for example, Bennett says they added a number of "lesser-known groups, including beetles, micromoths, and true bugs" to the list, this past year.

Other newer additions track recent changes — like the appearance of cattails in Yukon.

They're a common wetland plant in southern Canada, but Bennett says they're novel in Yukon and their range is expanding rapidly.

"People from southern British Columbia or Ontario are very familiar with them and may not think anything of it, but currently there's only about 10 sites that we know of cattails [in Yukon]," he said.

Two of those sites were new, last year.

Other recent additions to the Yukon species list include the brown thrasher (a bird), the navigator water shrew (a mammal) and plant species such as a variety of goosefoot and Alaskan Jacob's ladder.

Walrus in Yukon

Mammals make up a tiny fraction of Yukon's known species list, so it's significant when another is added.

This year, the walrus is added, in addition to the shrew.

Bennett says people have talked of seeing walrus on Yukon's northern coast in the past, but there was never any definitive documentation. He says he was in Inuvik recently and mentioned that to a local woman he knew.

"She said, 'oh, I've got a photo of a walrus from Yukon,' and picked up her phone and showed me a walrus that was from Moose Channel, in Yukon."

That sighting was not necessarily odd or shocking; Bennett says some species have just been poorly reported in the past.

'Things are changing so violently'

A stranger recent sighting in Yukon was the willow ptarmigan, found breeding in an area burned by forest fire, "many, many kilometres from where we would expect ptarmigan," said Dave Mossop, a professor emeritus at Yukon College.

"Ptarmigan are a tundra bird and this is a population that's occupying a valley bottom that's burned. So it was shocking ... being a skeptical biologist, I simply didn't believe it at first," he said.

Mossop says researchers are "perplexed" and need to do further work to figure out how many of the birds are there and whether breeding is a common thing there now.

"It's one of those things that is troubling — in the North, things are changing so violently, it's amazing," he said.

"The old idea that there is some kind of debate about climate change — there's no debate in the North about climate change, there's no question it's happening. And some of these changes are actually quite troubling."

Critical details to track change

Bennett says maintaining and updating the Yukon species list is crucial for tracking ongoing change, such as "shrubification, loss of lands, change of ranges, species using novel habitats."

He says all Yukoners can help, by reporting any unusual or unexpected plant or animal sightings to the Yukon Conservation Data Centre.

Some of the most interesting and valuable information, he says, is the first and last known sightings of a particular species in a given year.

"Those sort of details, those are going to be really critical for the future as we follow the changes of climate change," he said.

"People are interested in the land, people are seeing the land change, and we are there to try and at least capture some of your observations," Bennett said.