Rennes population reductions could be devastating

REindeer is almost synonymous with the North Polar. Recognized for their woods of imposing, their thick winter coats and their ability to survive in difficult environments, these majestic creatures are from Tundras and icy forests in North America, Siberia and Northern Europe. Historically, reindeer played a huge role in helping humans regulate these icy latitudes, and are vital for ecosystems and cultures in the place where they live and wander. But a new analysis suggests that they are in serious danger.

The world’s world populations (also known as Caribou) have already dropped by two thirds in the past three decades. This prompted a team of researchers from Denmark, the United States and Australia to try to map what the future looks like. Using a wide range of data on the dynamics of the population and the geographic range over 21,000 years, including fossil recordings, old DNA, recordings of human migration, as well as Paleo reconstructions and historic climate and climatic projections – the team has created cards where reindeer could survive in the future.

Changes in the environment due to climate change are wreaking havoc.

These cards suggest that reindeer populations could decrease up to 80% in certain parts of the world between today and 2100. “Unfortunately, some of these caribou populations will suffer a lot from future climate change, whether from a road scenario or a worst scenario of the worst case,” said Elisabetta Caneri, an ecologist from the University of Adelaïde and the University of Copenhage. The document is published in the journal Scientific advances.

North American populations seem to be in particular dangers, due to more limited areas of appropriate land and greater changes planned in the use of land on the continent than in Europe or Asia, explains Canceri. This means that the populations of Rennes who find themselves in difficulty will find it more difficult to find new territories to which they can migrate.

Rennes population drops could be devastating not only for reindeer but also for plants, animals and human communities that depend on it. Rennes and caribou eat small young divers, which helps prevent forests from overflowing and listening to other flora species, which in turn helps to mitigate global warming. They are also an important species for indigenous communities – which use animals for transport and food, their woods and their bones for tools and their fur for clothing. Animals are also symbolically important for indigenous cultural identity. A death of some of these Rennes populations could be “really stressful” for people who depend on it, explains Canceri.

REindeer evolved around 21,000 years ago to the last glacial maximum – and they survived other previous episodes of rapid warming, explains Damien Fordham, an environmentalist at Australia University of Adelaide who co -written research. But today, temperature changes are aggravated by other threats focused on humans and the number of populations already exhausted. “With global populations already reduced by almost two thirds in just three decades, other losses of Rennes and Caribou will destabilize the biodiversity of the tundra, decrease carbon storage and intensify climatic comments.”

The animals are only adapted to a set of colder and drier conditions – and changes in the environment due to climate change are wreaking havoc. Summer thermal stress, which occurs more often with climate change, can have them arrested to eat To avoid overheating, explains Eric Post, an environmentalist at the University of California in Davis, who co-written research. “When they stop, they don’t eat, and that means they enter winter with less body mass,” he said.

In addition, hot winter spells melt the upper snow layer, which then goes up when it is cold again, creating a layer of ice that can be difficult or impossible for Caribou to dig to find food. Families of mass can result. “Add to these other factors such as disease, parasites, human encroachment and other forms of loss of habitat and you consider climate change as a threat multiplier,” explains Post.

The reindeers that find themselves in difficulty will find it more difficult to find new territories.

Elie Gurarie, environmental biologist at Suny’s College of Environmental Science and Forestry which has not been involved in the new research, says that new research is an “innovative and very important look at the engines of the populations of Caribou and Rennes since the last glacial period combining a vertiginous range of data types”.

There is still a great uncertainty in the models, however, says Gurarie. “Caribou populations fluctuate considerably during multi-decade cycles, and despite a century of intensive western scientific research, and many generations of experiences lived by the Aboriginal peoples of North America and Eurasia, the ultimate causes of these fluctuations are very badly understood.”

He adds that in addition to climate change, the caribou is faced with unprecedented pressure of industrial development, in particular roads and ports – across the Arctic. “This type of development threatens to undermine this very superpower which allowed them to prosper: their large -scale mobility and their ability to move or disperse.”

Anne Gunn, an independent expert who worked with the government of the Northwest Territories as a field biologist, says that collectively, scientists know less about conservation status and landscape changes in Russia – she therefore says that the context should be a priority for research rather than North America.

For Canceri, advice on the future are still in the past. “The past can really be good to inform for the future,” she says. “The fact of continuing from the past to the future will be very important for conservation measures and to better predict what will happen to species.”

While their figures decrease, royal reindeer can become an increasingly rare spectacle in the far north – a recall to much older and colder times.

Image of lead: Zaclaharia / Shutterstock

• Katharine Gammon

  Published on August 27, 2025

  Katharine Gammon is an independent scientific writer based in Santa Monica, California, who writes on the environment, science and parenting. You can find it on X (formerly known as Twitter) @kategammon.