Canada’s migratory caribou are under threat. Will we act before it’s too late?

Delegates are gathering in Campo Grande, Brazil, for the 15th Conference of the Parties (COP15) on the Convention on the Conservation of Migratory Species of Wild Animals. The meeting aims to address growing threats to migratory animals — from birds and whales to large land mammals. The outcome could matter for caribou — one of Canada’s most recognizable wildlife species, immortalized on the country’s 25-cent quarters. Canada has not ratified the convention, but COP15 still matters here: it sets global norms and shines an international spotlight on a crisis unfolding in Canada’s North. Every year, migratory tundra caribou travel hundreds — sometimes thousands — of kilometres across the Arctic and subarctic. These journeys are the longest known terrestrial migrations on Earth.

As large herds of caribou migrate between the boreal forest in winter and the tundra in summer, they move nutrients across vast landscapes and shape vegetation, soils and food webs. Their migrations also sustain Indigenous cultures and ways of life across the Arctic. For Inuit in Kugluktuk, caribou are part of a relationship of respect and reciprocity that supports physical, cultural and spiritual well-being. Generations of lived experience on the land have produced an deep understanding of caribou. But today, caribou migrations are in peril. Once numbering around 470,000 animals, the Bathurst caribou herd has collapsed by more than 99 per cent since the 1980s. Today, only about 3,600 remain. Within a single human lifetime, one of the great migrations of the North has nearly disappeared, a decline witnessed first-hand by people in Kugluktuk. Other herds across the North American Arctic tell similar stories, with devastating effects on Indigenous communities. Navigating the perils of a changing Arctic Animals learned to migrate because it helps them survive. For caribou, travelling long distances to calving grounds offers major advantages. First, migration allows females to time giving birth with the brief burst of nutritious spring vegetation, when plants provide the protein levels needed for females to nurse growing calves. Second, when tens of thousands of females gather to give birth within a short window of time, predators such as wolves and bears can only consume a small fraction of calves — a phenomenon ecologists call “predator swamping.” But the ecological conditions that once made caribou migrations so effective are changing. New research indicates caribou populations could decline 80 per cent by 2100

Arctic warming is altering vegetation growth in northern ecosystems. In many regions, plants growth is starting earlier in spring. Migratory animals like caribou may not always adjust their movements at the same pace, potentially creating mismatches between migrations and peak food availability. Climate change may also be reshaping species interactions. Grizzly bears appear to be increasingly present in parts of the tundra where they were historically less common, potentially increasing predation during the calving season. We recently conducted research into this trend, along with colleagues, using a large network of camera traps. We documented substantial overlap between grizzly bears and Bathurst caribou during calving. If predators are increasingly present where calves are born and climate change affects the timing of resources available to mothers, migration may no longer be as advantageous. Infrastructural barriers to migration Migration depends on something deceptively simple: space. Caribou must be able to move freely across vast landscapes. Around the world, roads, fences and other human infrastructure have fragmented migration routes and limited the space available to animals. The Arctic remains one of the last places where large-scale terrestrial migrations still unfold largely intact. But that distinction is increasingly under pressure. Proposed infrastructure projects such as the Arctic Economic and Security Corridor in northern Canada and the Ambler Road Project in Alaska would cross hundreds of kilometres of key caribou migratory routes. For Indigenous communities, the stakes are high. People from these communities have repeatedly raised concerns about the potential impacts of such projects. Their voices, and the land-based knowledge that informs them, must be central to planning and consent processes. Too often, consultation occurs only after major decisions have already been made and local voices are muted. Where development proceeds, Indigenous Peoples must also be meaningful beneficiaries rather than communities left to bear the ecological and cultural costs of projects that threaten the wildlife they depend on. Studies of caribou and other migratory ungulates show that roads and industrial activity can disrupt movements, reduce landscape connectivity and affect survival. These concerns have led some Indigenous organizations to oppose new road construction and resource development in caribou habitat, citing the long-term risks to herd viability. Together, Inuit and scientific knowledge contribute to wildlife co-management, and under Nunavut’s co-management system, Inuit are a strong voice for wildlife — especially caribou. Protecting migrations in a changing world Globally, migratory species are declining at alarming rates. A recent United Nations report found that nearly half of migratory species are experiencing population declines. This week, governments from around the world are in Brazil for the Convention on the Conservation of Migratory Species of Wild Animals. As a non-party to the convention, Canada is not bound by its outcomes — but the moral and diplomatic pressure to act is no less real. Indigenous-led conservation aims to rekindle caribou abundance and traditions

The tools exist: transboundary protections, migratory corridor designations and co-ordinated limits on industrial development in critical habitat. What’s lacking is the political will to apply them at the scale the crisis demands. For these measures to succeed for caribou, they must also incorporate Indigenous land rights alongside practical mitigation measures — such as seasonal traffic restrictions — that allow caribou to move freely across their migration routes. Protecting caribou migrations also requires confronting the broader climate crisis driving Arctic change. The Arctic is warming nearly four times faster than the rest of the planet, and the phenological mismatches and shifting species ranges that threaten caribou will only intensify as greenhouse gas emissions rise. That means saving caribou migrations ultimately demands a rapid and genuine reduction in our collective carbon footprint. As delegates gather in Brazil, the fate of Arctic caribou migrations should serve as both a warning and a test. Caribou migrations are among the great natural wonders of our planet. Whether future generations will still witness them depends on decisions being made right now — and on whether those decisions finally centre the peoples who live with, and for, the caribou.

Benjamin Larue receives funding from the Liber Ero Postdoctoral Fellowship, the World Wildlife Fund and the National Geographic Society. Allen Niptanatiak and Amanda Dumond do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.