A weekly feature named ‘The Hunter’s High Road.’ Each Tuesday check back to see an animal that represents the apex of predatory evolution. Carnivores come in a range of shapes and sizes, using a variety of tricks to catch their prey. Some are powerful, some are beautiful. All are deadly.
Strength plays a large role in a carnivore’s ability to take down prey. And few others match the strength of a polar bear when it’s in the middle of a hunt. Considered the largest land predator alive, the polar bear is actually a marine mammal because it spends months of the year at sea. Powerful limbs ensure it is capable of covering miles on foot in wintery lands such as Canada, Alaska, Greenland, Russia and Norway.
Adult male polar bears reach up to 7-9ft long and weigh between 350-700kgs. They are perfectly adapted to their environment with large feet to distribute weight when walking on snow and ice, or to provide propulsion in water. The pads of their paws are covered with small dermal bumps which are beneficial for traction. Their claws are short and stocky in order to grip prey. The scooped nature of the claws helps the polar bear to dig and shift ice rapidly.
A thick, 4 inch layer of blubber provides superb insulation along with a strong hide and fur. Polar bear fur is made up of dense underfur and an outer layer of guard hairs which appear white but are actually transparent. The hair usually turns yellow as the bear ages. As expected, polar bears are exceptional swimmers who will swim for days at a time. One female was recorded to have swam for 9 days in the Bering Sea and travelled 400 miles. The bear’s blubber provides buoyancy and it swims in a dog paddle fashion using the large forepaws.
Polar bears subsist mostly on seals, hunting them across the ice with a highly developed sense of smell. They are able to detect seals from nearly a mile away, even when they are buried under 3 feet of snow. The long muzzle and neck help the bear search in deep holes in which it practices a still-hunting technique. The bear waits in silence over a seal breathing hole and when the prey surfaces it drags the seal out. Polar bears are also known to prey on beluga whales and walruses but they are difficult to subdue due to size and weight.
Mating takes place on sea ice between April and May. Males fight viciously with each other to earn breeding rights. Partners stay together and mate repeatedly for a week. Once the cubs are born they are helpless and are typically nursed for two and a half years.
Despite their fearsome appearance, polar bears are normally cautious in confrontations and prefer to escape rather than fight. They don’t normally attack unless provoked, yet hungry polar bears are unpredictable and may hunt humans if they are desperate. Japanese wildlife photographer, Michio Hoshino, observed a hungry polar bear running after him in Alaska. He was able to reach his truck and drive away as the bear ripped off one of the doors.
Like many animals living in Arctic regions, polar bears are under threat from climate change, pollution and habitat loss. Rising temperatures cause sea ice to melt and bears are forced to shore before they have built up sufficient fat reserves to survive periods of scarce food. Statistics on the global population of polar bears has been recorded as 18,349 in July 2013 by the IUCN Polar Bear Specialist Group.
Polar Bears International is a charity that campaigns to reduce the destruction of sea ice and help preserve bear habitats. They include such things as a petition you can sign addressed to leaders attending the 2015 United Nations Climate Change Conference held in Paris this December.
Polar bears are awe-inspiring for their strength and reputation. Protecting them is easy – all you have to do is reduce the risk of climate change. Recycle, replace lights, use water responsibility, spread the word. Every little bit helps.