If you’re reading this on the web or someone forwarded this e-mail newsletter to you, you can sign up for Globe Climate and all Globe newsletters here.

Good afternoon, and welcome to Globe Climate, a newsletter about climate change, environment and resources in Canada.

Today, we’re looking at the Arctic migration of a famous boreal rodent and the change the animals are bringing with them.

Note: There will be no newsletter on Monday, May 18 as the team takes a break for Victoria Day. However, our website will be staffed throughout the long weekend so please visit us online at globeandmail.com. We’ll be back in your inbox on May 25. Enjoy your long weekend.

Now, let’s catch you up on other news.

1. Weather: Wildfire season already affecting B.C. and Alberta
2. Wildfires: New push to set national standards for wildland firefighting protective equipment
3. Resources: Fertilizer shortages and rising fuel prices could trigger food crisis across Asia
4. Ecojustice: Community leaders ask judge to overturn B.C. regulator’s support for $12-billion pipeline plan
5. Oil and gas: Ottawa suggests letting cabinet green-light pipelines before technical assessments happen
6. Regulations: Rhino rancher seeks South African court’s approval to export 479 rhino horns to Canada
7. Arts: Six environmental artists win this year’s Rewilding Art Prize

For this week’s deeper dive, the spotlight is on beavers and their transformative migration into Canada’s Far North.

The signs were unmistakable: gnaw marks on trees and shrubs, rapid and lasting change to local waterways. And of course, numerous sightings of the semi-aquatic mammals who typically live in warmer climates.

Inuvialuit communities have long witnessed beavers moving into the Far North in rapidly growing numbers. Now, research published in the journal Ecosphere is supporting those observations.

Jenn Thornhill Verma’s feature on the famous rodents’ northward migration details how researchers traced their path and how the critters have transformed the landscape.

The beavers’ journey was driven by climate change, the study found, and they’ve travelled as far as the Arctic Ocean in the Inuvialuit Settlement Region, or ISR – the westernmost region of Inuit Nunangat.

Almost a decade ago, residents of lower Mackenzie Delta communities started raising concerns about the impact the influx of beavers was having on their fishing and travel routes, and on drinking-water quality. By 2020, people described seeing beavers in almost every waterway in the area.

A few years later, the animals had been sighted by the Beaufort Sea. One man, a local resident who was part of the research team, described being stunned when he saw a beaver swimming in the ocean off the coast of Yukon.

To trace the beavers’ path, researchers worked with local community members to survey 60 beaver lodge and dam sites along a 130-kilometre stretch of the Inuvik–Tuktoyaktuk Highway.

The work used tree-ring analysis, examining gnaw marks in shrubs, combined with satellite imagery of changes to surface water from beaver dams.

They compared the gnaw marks on willow and alder shrubs against growth rings of undisturbed shrubs to date the beaver activity. Through that comparison, they found evidence of continuous beaver presence in the region from at least 2008, as far north as the tip of the Northwest Territories.

The migration has been picking up its pace, the study found. Satellite imagery and gnaw marks near one large lodge-dam complex showed a significant increase in beaver activity between 2015 and 2019.

It’s part of a larger trend of boreal species migrating into the Arctic as the climate warms. Moose, snowshoe hare, river otter and muskrat have also pushed further north in recent years.

But according to the lead researcher on the study, beavers leave uniquely visible traces of their activity and the ecological change they bring about.

“Beavers effectively write their history into the landscape with each shrub they cut and every pond they create,” Georgia Hole of Durham University said in a news release about the findings.