A Bathurst caribou bull near Contwoyto Lake in the Kitikmeot Region of Nunavut, Canada. Photo credit: Petter Jacobsen
A striking decline
New maps show shrinking caribou migrations
For centuries, the migrations of massive herds of caribou defined the ecosystems and lifeways of Indigenous People across the vast Canadian Arctic. Migratory caribou connect tundra, boreal forest, predators and people—enriching landscapes ecologically, sustaining the region’s carnivores, and shaping the cultures of the Indigenous communities that have harvested them for generations. But today, these migrations and the large herds they sustain are hanging in the balance.
As JANEY FUGATE writes, new maps are drawing attention to looming changes to the Bathurst caribou’s migratory range and highlighting opportunities to protect the connections that hold this system together.
The Bathurst herd of barren-ground caribou, named for their historic calving grounds near Bathurst Inlet, once ranged from Nunavut all the way to northern Saskatchewan. Some caribou travelled more than 500 kilometres on their yearly migrations. The annual pulse of their movements across the landscape provided food and sustenance for humans and other wildlife alike.
Today, the herd is declining. The population, which numbered about 400,000 in the 1980s, had fewer than 4,000 members in 2025, according to recent surveys. But it’s not just their numbers that are dwindling. The herd’s migratory range has also contracted. In response, the Global Initiative on Ungulate Migration partnered with WWF-supported researchers and Indigenous stewards to map the Bathurst caribou migration in new detail.
A broad goal of the initiative is to promote connectivity across migratory landscapes—and we’ve found that maps based on tracking data are powerful tools for identifying the areas that must stay connected for migration. Our new maps document critical habitat, show the historical extent of movements, and pinpoint emerging threats.
This map shows migration routes and seasonal ranges of the Bathurst caribou herd alongside roads, mines and land-use boundaries in Canada’s North. Map credit: The Global Initiative on Ungulate Migration (GIUM
A ROAD RUNS THROUGH IT?
The Bathurst’s range sits within the recently designated Arctic Economic and Security Corridor, a proposed $40 billion Canadian infrastructure project to build an all-season road from the Northwest Territories to a new deep-water port at Grays Bay, Nunavut. The project has received heightened attention from the Canadian government, with the prime minister recently adding the initiative to a list of “nation-building projects,” meaning it may be fast-tracked.
But our new maps illustrate how the road would cut straight through the Bathurst caribou’s core migration area, passing very close to the herd’s calving grounds and effectively bisecting the herd’s current range.
Three diamond mines already operate in areas known to be preferred by the herd. Indigenous stewards and researchers have documented large-scale caribou avoidance of these areas. Winter ice roads that service the mines can also act as barriers, limiting where and how caribou move across the landscape. When migration routes are disrupted in this way, animals may be delayed or diverted from critical feeding and calving grounds, contributing to further losses.
Caribou tracking data and detailed maps can help inform how development is planned, including where infrastructure is located and how it is designed. When used in this way, these tools can support decisions that reduce disruption to seasonal migrations.
Indigenous-led restoration and management
The caribou herds of the Arctic are among the only wild, migratory ungulate populations in the world to which Indigenous communities still maintain strong traditional ties—and their migrations are among the longest among ungulates in the world.
“The steep decline of the Bathurst herd is not just a biological concern. It represents a profound cultural and ecological loss,” says Orna Phelan, a wildlife biologist with the North Slave Metís Alliance (NMSA).
The Bathurst caribou herd now occupies a much smaller annual range than it did in the 1990s. Map credit: The Global Initiative on Ungulate Migration (GIUM)
Facing multiple threats
As one of the Indigenous communities that stewards the caribou, NMSA has said that conserving this herd also means safeguarding their history, their identity and the health of the land we all share.
The Bathurst herd is emblematic of the pressures facing migratory caribou worldwide. As a species, barren-ground caribou have declined by 65 per cent over the last 20 to 30 years.
They face multiple threats:
- rising temperatures
- increased insect harassment
- declining vegetation quality
- more frequent rain-on-snow events that lock away lichen—their primary winter food source—under thick ice
Need to move freely
In the Bathurst’s migratory range, Indigenous-led guardians, harnessing traditional knowledge and on-the-ground observations, are intensively monitoring traffic and caribou behaviour on and around roads and mines.
Working in close partnership, researchers are trying to understand how the caribou are responding to various kinds and levels of disturbance, with an eye toward specific mitigation solutions that can make linear infrastructure, such as roads, more caribou friendly.
Mapping methods tested in the Bathurst caribou’s range could prove useful for the other large caribou herds that still inhabit the circumpolar north, allowing these regions to avoid stark population declines and preserve the long-distance movements that caribou require.
“Among all the caribou’s astonishing adaptations to not only survive, but thrive, in the Arctic, perhaps none is more important than the ability to move freely across large landscapes,” says Elie Gurarie, a wildlife scientist who has studied caribou for a decade. By working closely with First Nations, Inuit, territorial governments and nongovernmental organizations, we’re not only documenting change, but shaping solutions.
Bathurst cows and calf. Photo credit: Petter Jacobsen
By Janey Fugate
JANEY FUGATE is a Project Manager for the Global Initiative on Ungulate Migration, a consortium of scientists building an open access tool that makes migration maps available for use in spatial planning.
