Churchill, Manitoba, is a town built on polar bears. Slightly over 900 of the massive predators roam the nearby tundra, forming the basis of a tourism industry that every fall draws thousands of visitors (and millions of dollars) to this fly-in hamlet on the southwestern shore of Hudson Bay. But with sea ice disappearing at a record pace, scientists estimate that the ursines could become extinct by mid-century. When the bears go, what will happen to the people who depend on them?
Churchill's association with polar bears goes back to at least 1619, when Norwegian explorer Jens Munk and his crew shot and ate one while wintering over in the area. "It was of good taste and did not disagree with us," Munk wrote in his journal. Most of his crew would later die of a combination of scurvy and trichinosis, likely from eating undercooked bear meat.
Polar bear encounters are most common in October and November, when the region's bears gather on the shore of Hudson Bay to wait for the annual freeze.
Tourists and film crews view the bears from buggies, huge all-terrain buses that are constructed almost entirely in Churchill. Equipped with plush suspension, low-pressure tires, and massive 460 International Diesel engines, buggies are designed to float effortlessly across mud and snow.
A polar bear sits on the shore of Hudson Bay. Churchill's bears depend on the bay's annual freeze to hunt their main prey, ringed and bearded seals. The average bear consumes about 43 seals a year.
Polar bears' vulnerability to climate change has made them a bellwether species for global warming. Researchers estimate that western Hudson Bay's bear population could disappear within the next 30 years.
While some people hope that polar bears will be able to adapt to a warming world, researcher Andrew Derocher of the University of Alberta says that's fantasy. "The problem is, they're a highly-evolved species to deal with an extremely specialized habitat," he says. "They make their living eating the fat of seals. You take that away from them, there's no way they can persist."
A dog protects its food from a polar bear at a kennel outside Churchill. Conflicts between humans and bears have increased over the past decade as sea ice has diminished.
Polar bears that can't be frightened away from human settlements are captured and housed in a "jail" run by Manitoba Conservation until they can be relocated.
A sign warns pedestrians away from an area frequented by polar bears. Conservation officers from Manitoba's Polar Bear Alert Team are on call 24 hours a day to scare off or capture bears that wander into populated areas.
Churchill's port has been suggested as a possible export point for oil from Alberta's tar sands, and could be one of the few possible sources of revenue to the town if a decline in the polar bear population causes the local tourism industry to collapse.
Two polar bears spar. These playful matches rarely end in injury, and prepare male bears for the brutal fighting that goes on during mating season
A mother bear and her two cubs wander through the tundra.
Two polar bears spar as tourists watch. Polar Bears International and Explore.org stream the polar bears' annual migration from a specially-equipped buggy that can stay out on the tundra for a week at a time.
A young bear peers through a grate in a buggy's floor.
A ptarmigan camouflages itself against the snow. Besides polar bears, various species, including belugas, arctic owls, bearded seals, red and arctic foxes, and wolves, call the Churchill area home.
While Manitoba doesn't have a polar bear hunt, traditional and sport hunting in other areas has a significant impact on populations. Thirty-seven bears were taken by hunters in the western Hudson Bay region in 2011.
With males reaching weights of 1,500 pounds, polar bears are the world's largest terrestrial carnivores.
A pair of bears spar in the snow.