Aerial photos show 11,000 beavers ravaging Alaska’s tundra like wildfires.
- Beavers invade Alaska’s arctic tundra like heathers, changing the landscape like wildfire.
- Satellite images show rivers turning into trains of watery ponds as beavers build their dams.
- Animals benefit from climate change, but their mothers can also accelerate warming.
- For more stories, visit Business Insider.
Beavers are encroaching on Alaska’s tundra, completely altering its waterways and accelerating climate change in the Arctic.
The changes are so sudden and drastic that they are clearly visible from space.
As the Arctic tundra warms, trees grow along its rivers and streams, creating perfect habitat for beavers.
As the furry rodents move through these waterways, they settle in doing what they do best: chew and carry wood to build dams, dam rivers and creeks, and fast rivers to create watery ponds.
What was once a thin line of water through the tundra has become a train of bulbous beaver ponds:
“There aren’t many other animals that leave a footprint that you can see from space,” Ken Tape, an ecologist at the University of Alaska Fairbanks, told Insider. “There is one and they are called human. “The funny thing is that people couldn’t get permission to do what the beavers are doing now in this situation.”
The occupation of this free-swimming, furry rodent in the North American tundra is mixed. Beaver ponds create lush oases that can boost biodiversity, but they also play a role in accelerating the climate crisis.
11,000 new beaver ponds
Tape and his colleagues evaluated aerial photographs from the early 1950s and found no signs of beavers in Alaska’s arctic tundra. The first signs of beavers appeared in pictures from 1980. Beaver ponds doubled in satellite imagery from the 2000s and 2010s.
In total, satellites reveal that more than 11,000 beaver lakes have appeared in the tundra.
“All of western Alaska is now very densely populated with beaver ponds,” Tape said.
This is consistent with what indigenous peoples in the region have observed. That’s especially evident in towns like Kotzebue, where beavers were absent 20 years ago and are now everywhere, Tape said.
The researchers published their findings in May in the journal Scientific Reports. Tape presented the research at the fall meeting of the American Geophysical Union in December, just as the National Oceanic and Atmospheric Administration released its annual warning on how quickly the Arctic is succumbing to climate change.
From space, Alaskan beavers are as effective as wildfires
Tape previously used satellite imagery to look for changes in vegetation—slow, subtle changes in the appearance of the tundra.
So he was shocked to see beaver engineering projects that were completely transforming Alaska’s landscapes.
“It was like hitting the ecosystem with a hammer.
Tape said the weight and speed of beaver tracks in the landscape seen from space is more like a forest fire.
Satellite images answer two key questions for studying any animal population: Where are they? And how many people?
The most interesting question is yet to come: how exactly do beavers change everything around them?
From fish and vegetation to water flow and quality and its downstream effects, there is still much to learn.
Champions of the New Arctic
Beaver ponds are warm oases in the tundra because the calm, deep water holds more heat than the once-flowing rivers.
Tape expects these pond areas to begin to look more like boreal forest than tundra. Calm water will likely attract waterfowl and new species of fish.
“If you like the Arctic like the old Arctic, beavers are bad for it. But if you’re kind of embracing the new Arctic, beavers are one of your champions,” Tape said.
One thing that’s impossible in the new Arctic is the thawing of permafrost—layers of land that normally remain frozen year-round. Permafrost covers about a quarter of the northern hemisphere, including about 85% of Alaska.
As temperatures rise, permafrost melts and releases greenhouse gases, carbon dioxide and methane into the atmosphere.
The only beaver effect Tape’s team is sure of is this: Beaver ponds are melting the surrounding permafrost, exacerbating the climate crisis. How much is not yet clear.
New Frontiers for Pioneer Beavers
As the Arctic warms, more beavers will spread across the tundra in the future, continuing to move northward.
The northernmost strip of Alaska, north of the Brooks Range, is still largely beaver-free, Tape said. But it may not stay that way for long. Dense beaver populations are found on the edge of the mountains.
“All they have to do is swim downstream,” Tape said. “If they find a habitat there—in other words, if it’s warm enough, if the bushes are tall enough, if there’s enough unfrozen water in the winter—then they’ll change it forever.”
