Grizzly Bears: Drama of the Alaskan Salmon Run

During the Alaskan salmon run, grizzly bears concentrate on the rivers in huge numbers. But as they group to hunt the cubs must be protected.

Grizzly bears are among the world’s largest land predators. These animals are perfectly adapted to their environment with keen eyesight, an acute sense of smell and incredible strength and power.

I flew to Katmai National Park to see the bears as they feasted on red salmon, known as sockeyes. These fish swim in from the pacific ocean each summer to reach their breeding grounds. In places, the river is pink with salmon.

Salmon are a vital food source for grizzly bears. They are rich in fats and high in calories. Just one fish provides around 4,500 calories, and they can eat over 20 a day. That’s a staggering 100,000 calories, 40 times what I eat!

During the salmon season grizzly bears go into a phase of hyperphagia; which means they have an insatiable appetite, but never feel full. This drives their need to continually feed and helps them build the fat reserves they need to get through winter hibernation.

I watched up to eight bears at any one time and quickly noticed their individual hunting techniques. One would hold his paw up just before he dashed into the water, whilst another preferred to stay up on the bank with her cub as she watched the summer, ready to pounce.

Because the salmon are so abundant; the bears can afford to be selective. They prefer female fish for their nutrient rich eggs and can easily tell them apart since the males have larger heads and a hump on their backs. The bears only eat the fattiest parts of the fish, but there are always gulls to swallow what they discard so nothing goes to waste.

Mother bears can have as many as four, but two is the norm. Born in winter, they spend their first months tucked away in a den before emerging in spring. Grizzly bear cubs will spend their first two years with their mother, before setting off on their own. In their first year, these youngsters will grow 10 times their spring weight.

Male bears sometimes kill cubs to force the females into oestrus. The mother bears are therefore wary and tend to keep their cubs away from the rest of the hunting bears. Watch the film to see one mother bear quickly call her two young away when she spots two males approach. It’s been a real privilege to spend time out here with the bears… and I can’t wait to come back to Alaska, to experience this again!

#bears #grizzlybears #robertefuller