Polar bears aren't the only beloved Arctic animal threatened by climate change. Scientists believe reindeer are at risk as a warming world makes their main winter food source disappear.
But reindeer on one Alaskan island are surprising researchers.
And that surprise doesn't just come from the fact that the reindeer are hard to spot.
On St. Paul Island, Lauren Divine of the EcoSystem Conservation Office was not having luck seeing a herd of 400 reindeer, even on this treeless island with tundra as far as the eye can see.
Divine helps manage the reindeer on the island, but on this windy day, she's hunting them.
Reindeer aren't native to Alaska. They were brought to rural villages across the state in the late 1800s.
In communities like St. Paul, where grocery prices are astronomical, Divine says residents depend on reindeer to feed their families. And to make it through winter, the reindeer need something as well.
"Reindeer all over the world depend on lichen," Divine says. "They're very high in sugars and starch, and they're considered like a Snickers bar for reindeer in the winter."
But the reindeer on this island ate the lichen faster than it could regrow. Now, it's gone.
Without lichen, reindeer experts would expect to see malnourished or starving animals. And in some places, that's already happening. But the animals on St. Paul Island are thriving.
Greg Finstad, with the University of Alaska Fairbanks Reindeer Research Program, came to study and evaluate the island's reindeer and environment.
On a visit to the island last year, he saw something he had never witnessed before.
"The reindeer are doing something really very interesting," he says. "They have managed to find other things to eat. They've gone underground."
Finstad discovered that instead of lichen, the reindeer are digging up roots and grazing on grass. He says that's good news.
Lichens thrive in arctic climates, but the Arctic is warming faster than the rest of the globe. These higher temperatures mean more wildfires, erratic rainfall and better conditions for other plants that can crowd out the lichen. All of this could mean less lichen for reindeer.
On top of that, a warmer climate means what used to be snow is now rain. A few years ago in Russia, that created an icy barrier so thick the reindeer couldn't stamp through it to get to the lichen. Tens of thousands starved to death.
That's why Finstad thinks it's important that the reindeer in St. Paul are finding something else to eat.
"There's a lot of scientists, researchers, reindeer producers waving their arms in the world [saying] 'Oh climate change, it's the death of reindeer and caribou,' " he says. "But you know what, we have forgotten to tell the reindeer and caribou. Things change, and they change with it."
But ecology professor Mark Boyce of the University of Alberta is not convinced.
"It's an island population, and a very small sample of our global populations of reindeer and caribou and the general pattern has been one of decline," he says. "So I guess I'm not very optimistic."
Still, on this island, reindeer are doing just fine for now. And hunting them is more popular than ever.
This report comes from Alaska's Energy Desk, a public media collaboration focused on energy and the environment. Zoë Sobel is a reporter for member station KUCB in Unalaska, Alaska.