Caribou 'story map' shows tale of recovery, expansion in Southern Lakes herds

Twenty-five years ago, Lars Jessup would have had to chase faint radio signals from an airplane, just to find out where the caribou he monitors had roamed.

Today, thanks to new GPS collars, he can download that data daily, to his phone.

Now, Jessup, Environment Yukon's Southern Lakes regional biologist, says his department has put that data to use in developing a new set of interactive online tracking tools they're calling a "story map." The interactive map tells the story of the herds' tentative recovery, and the efforts of researchers to collect new data on their health and movements.

"It's an effort from my branch and our section to share some of the really interesting work we're doing on the Southern Lakes caribou," he said.

The Southern Lakes caribou include four woodland herds that live near the lakes that cluster around the Yukon-B.C. border, including Lake Laberge, Atlin Lake, and Teslin Lake.

These caribou have been under a recovery plan since 1993, when the population of some herds fell to just a few hundred animals amid increasing human settlement in the area.

That plan, whose iconic logo is seen on many bumpers in the region, banned hunting the caribou, and six First Nations in the area voluntarily suspended their harvest. Since then, the numbers have rebounded.

The map shows more than just the southern caribou. It includes approximate ranges for all of the territory's caribou herds, including the migratory barren-ground herds of the North.

But it's in Jessup's own backyard where the use of the new GPS technology has yielded the greatest surprises.

"The extra thing about collars is they give you all of the great information … about caribou and how they use the landscape," he said. "We're learning where they winter, where they rut, [and] how they get … between them." 

That's especially important for the Carcross herd, which clusters on land between the busy Klondike and Alaska highways south of Whitehorse.

"So, where do they cross highways? How do subdivisions or gravel pits or other human development impact their use of the land?" asked Jessup.

"I'm hoping that people find this interesting, but also, this is an opportunity for people to see just how the caribou … are using the landscape in relation to their own activities," he said.

The interactive website also includes information on how and where wildlife officers have collared the caribou — accompanied by mugshots of the tagged animals.

Jessup says the GPS collars allow the department to use a more accurate "mark-resight" method of counting the herds, which uses a ratio between collared and uncollared caribou in an area to estimate the size of the population.

In the case of the Ibex herd, which was GPS collared for the first time just last year, the data is already showing encouraging results.

The herd, which roams the land southwest of Whitehorse, has seen its numbers rebound, and has expanded its range west of Kusawa Lake and further into northern B.C.

"We have a lot of longtime Yukoners who have experience with that area who have never seen caribou there before," he said.

Jessup says the department should have updated population estimates for the Southern Lakes caribou — the first in more than 10 years — sometime this year.

That will be followed by more detailed reporting on the herds' movements, particularly around areas of human settlement, in a few years' time.