THE GRIZZLY BEAR

BRIEF INFO Sub species of brown bear Endangered Most adult female grizzlies weigh 130– 200 kg (290–440 lb), while adult males weigh on average 180–360 kg (400–790 lb)

WHY IS IT A KEYSTONE SPECIES? In North America, the grizzly bear is a keystone species—not as a predator but as ecosystem engineers. They transfer nutrients from the oceanic ecosystem to the forest ecosystem. The first stage of the transfer is performed by salmon, rich in nitrogen, sulfur, carbon, and phosphorus, who swim up rivers, sometimes for hundreds of miles. The bears then capture the salmon and carry them onto dry land, dispersing nutrient-rich feces and partially eaten carcasses. It has been estimated that the bears leave up to half of the salmon they harvest on the forest floor

GEOGRAPHY Brown bears are found in Asia, Europe and North America giving them one of the widest ranges of bear species. North America, the species is now found only in Alaska, south through much of western Canada, and into portions of the northwestern United States including Idaho, Montana, Washington and Wyoming, extending as far south as Yellowstone and Grand Teton National Parks