If you were to walk in the Arctic tundra and came across an Arctic fox den, you’d probably see it a mile away. Not because the fox itself is visible (they’re masters of disguise) or because their den is visible (it’s usually well-hidden), but because there’s a lot of green vegetation around it.
We tend to think of gardening as a truly human endeavor, but other animals may also do it — though they may not necessarily realize it. All predators provide ecosystem services such as nutrient cycling when they hunt other creatures, but in the case of Arctic foxes, the effect is more pronounced.
For starters, these foxes live in nutrient-poor areas like the Arctic tundra, so when they recycle nutrients through their prey, the effect is much stronger. But it goes even deeper.
Foxes tend to reuse their dens over multiple generations; some are hundreds of years old. This means that the effect is also amplified over multiple generations. Over time, the land around their dens become greener and greener, contrasting with the barren land around them.
For Arctic foxes, their den is their lifeline. They use it to hide prey, rear their young, and hide from predators, as well as the fierce Arctic cold and wind. In a single season, they can catch hundreds of goose eggs along with other prey.
In the rugged lands which Arctic foxes call home, bringing this many nutrients can enrich the soil. Researchers used satellites and trackers to trace this effect, documenting the greening effect that Arctic foxes have on the surrounding environment. But since GPS updates are slow (researchers received an update every 3 days) and foxes move quickly. In the end, the researchers used a fixed-wing aircraft to get a better view of this greening.
“In conclusion, our study shows that Arctic foxes engineer Arctic ecosystems on local scales,” the researchers write. “By enhancing nutrient dynamics locally, Arctic foxes could have an important role in providing ecosystem services in the Arctic tundra landscape.”
So the foxes act as engineers, or gardeners, making sure the area around their den is green and lush.
Polar foxes are often overlooked when it comes to Arctic creatures — and the Arctic itself is often overlooked as an ecosystem — but these foxes show a remarkable ability to influence the environment around them.
However, Arctic foxes are in trouble. As climate change is reducing its habitat, the Arctic fox is also losing ground to the larger red fox. In some areas of northern Europe, some programs are in place to hunt red foxes, allowing Arctic foxes to remain in place. The Arctic is nothing if not unforgiving.
The study was published in Nature.