Interdisciplinary effort to understand caribou challenges

An interdisciplinary team of scientists and Indigenous people are working together to study how climate change and human development are impacting declining caribou herds in Canada and Alaska.

The team, including caribou researchers, vegetation ecologists, remote sensing specialists and representatives of native communities, hopes to be the first to look at caribou trends “across continental scales,” said Logan Berner, an assistant research professor at Northern Arizona University’s School of Informatics, Computing and Cyber Systems, who is helping lead the research.

“Caribou populations across the Arctic have declined by about 56% over the past few decades,” Berner said, citing a NOAA 2018 Arctic Report Card. “Some herds have declined by 90%.”

Funded through the National Science Foundation’s Navigating the New Arctic program, Berner and his colleagues plan to look at the movements and demographics of 10 barren-ground caribou (Rangifer tarandus) herds across the Hudson Bay to western Alaska in a standardized way. Their goal is to find out how a variety of factors are influencing caribou populations.

“Overall, we hope to better understand how climate change and human development impacted caribou populations across the North America Arctic over recent decades. This information can inform conservation of the populations to help ensure they persist over the coming centuries,” Berner said.

Although different herds may be affected in different ways, Berner said, researchers suspect climate change and land use are affecting caribou numbers. Warmer temperatures are allowing deciduous shrubs to outcompete lichen, a critical winter food source for caribou. Hotter summers are leading to more fires and drought. Industrial activities, like oil and gas development and mining operations, also impact the species.

“The Arctic is getting warmer, busier, and potentially riskier for caribou,” he said.

The team plans to tap into GPS data from caribou collared over the past two decades and satellite data to develop vegetation maps showing food availability. Part of the project will also include working with Indigenous people in the north who have observed changes in caribou populations and behavior.

“It is crucial that we consider and value the deep knowledge of people who have lived in these northern landscapes for many millennia,” Berner said. “We try to combine that deep knowledge with the strengths of western science to better understand the world in a more holistic manner. There’s so much intimate understanding that’s gleaned from living in a landscape. It’s the sort of thing we can’t see with a satellite.”