By Researchers for The Living Edens: Glacier Bay, Alaska's Wild Coast
Alaskan Brown Bear
Steller Sea Lion
Alaskan Brown Bear
(Ursus arctos horribilis)
The Alaskan brown bear is one of the largest North American land mammals. Adult males will occasionally weigh in at over 800 pounds. It is the same species as the grizzly, whose historic range covered much of western North America south to central Mexico. Today, they are found in only about two percent of their original range in the lower 48 states, but Alaska and Canada remain a stronghold.
Throughout most of their range, brown bears and grizzlies need a very large home range (50 to 300 square miles for females; 200 to 500 square miles for males), but in some parts of southeast Alaska, where the rich coastal environment provides an abundance of food, the bears have been know to live at densities as high as one per square mile.
Winter hibernation is usually spent buried in a snow or rock cave in the highlands. In March or April, they emerge and head for the coast, feeding on sedges, nuts and berries, clams, and anything else they can dig up. As midsummer approaches, the bears gather around the salmon creeks to fatten up on the spawning fish -- their ability to store fat being vital to their winter survival. In October or November, they return to the highlands in search of a den. One to three cubs are born during hibernation, and remain with the mother for two to three years.
The bald eagle is the national bird of the United States and the only eagle unique to North America. It is one of the larger eagles, with an incredible wing span. Once widespread throughout the continent, it is now only abundant in Alaska, the Pacific Northwest, Great Lakes region and Florida. Southeast Alaska probably has the greatest concentration, with one active nest found per mile of shore in some places.
Each fall, thousands of bald eagles gather along the Chilkat river near Haines, Alaska, where they fatten up for the winter on a late run of salmon. They feed on many small animals, but fish is a favorite food, and they spend much of their time near water.
A pair lays a clutch of one to three eggs in the late spring, which hatch about five weeks later. Usually, only one chick survives to adulthood. They are highly territorial, and a breeding pair shares guarding the nest and hunting duties. Life expectancy in the wild is not known.
Widest ranging of all seals, the harbor seal inhabits coastal waters throughout much of the northern hemisphere, where they feed on fish, squid, octopus and other small marine animals. They are one of the smaller members of the seal family, averaging five feet in length and weighing about 200 pounds. Normally solitary creatures, they gather in large concentrations in the spring to give birth to their pups.
In southeast Alaska, the icebergs in front of glaciers are the favored pupping grounds. One pup is born to most adult females each year, usually in early June. Pups learn to swim at just a few days old, and are weaned in four to six weeks.
The humpback whale is a widely distributed species, occurring seasonally in all oceans from the Arctic to the Antarctic, with distinct populations located in virtually every sea. All populations of humpback whale undertake vast migrations between breeding and feeding grounds, the most famous -- and longest -- of which is probably made by the Hawaii humpbacks, which travel to the Bering Strait and Alaska's Glacier Bay every year to feed.
Humpbacks average about 45 feet in length, with females tending to be slightly larger. They are characterized by stout bodies and very long flippers that have bumps, upon which barnacles may grow. The tail flukes are large and almost "wing-shaped." The underside contains patterns of black and white that vary from individual to individual.
Humpback usually feed within 150 feet of the water's surface, taking krill and shoaling fish such as herring, sandeel, capelin, and mackerel. They feed by engulfing tons of water, and then filtering food from it with their baleen plates. They have many methods of feeding, including bubble-netting, in which the whale dives beneath a shoal of prey and slowly begins to spiral upwards, blowing bubbles in a circular shape (and emitting a steam-engine sound) as it does so. These bubbles tend to congregate the prey in the center of the circle, and the whale swims up through the bubble-net into the center, with its mouth open to gulp up the prey.
Humpback whales often congregate in large, loose groups of tens of animals for breeding and feeding, but within these groups, they move individually or in the companionship of a few others. The most acrobatic of large whales, humpbacks are well-known for their breaches -- one was recorded breaching 200 times in a row -- lob-tailing, and flipper-slapping. Some humpbacks in Alaska have been seen rolling over icebergs in play.
The sockeye salmon, also referred to as red salmon, occurs in the North Pacific and Arctic oceans and associated freshwater systems. They range south as far as the Klamath River in California and northern Hokkaido in Japan, to as far north as far as Bathurst Inlet in the Canadian Arctic and the Anadyr River in Siberia.
While breeding, both sexes turn from silver to brilliant or dark red on the back and sides, and olive-green on the head and upper jaw. Males develop a humped back and elongated, hooked jaws filled with sharp teeth. Sockeyes are anadromous, meaning they live in the sea and enter freshwater systems to spawn, usually during the summer months. After hatching, juvenile sockeyes may spend up to four years in fresh water before migrating to sea as silvery smolt weighing only a few ounces. They grow quickly in the sea, usually reaching a size of four to eight pounds after one to four years. Mature sockeye salmon travel thousands of miles from ocean feeding areas to spawn in the same freshwater system where they were born. Little is known about the navigation mechanisms or cues they use on the high seas, although some evidence suggests that they may be able to use cues from the earth's magnetic field. Once near their natal freshwater system, sockeye salmon use olfactory cues to guide them home. Like all Pacific salmon, sockeye salmon die within a few weeks after spawning.
Aboriginal people considered sockeye salmon to be an important food source and either ate them fresh or dried them for winter use. Today, sockeyes support one of the most important commercial fisheries on the Pacific coast of North America, are increasingly sought after in recreational fisheries, and remain an important mainstay of many subsistence users.
Steller Sea Lion
Steller sea lions, also known as Northern sea lions, are the largest members of the Otariidae family, with adult males reaching nearly 10 feet long and weighing over a ton. They live throughout the rim of the North Pacific Ocean from California to northern Japan. They are highly gregarious creatures, gathering by the hundreds around haulouts and rookeries on offshore islands. Breeding season is from mid-May to mid-July.
Dominant males arrive early to establish territories on the rookeries, located on exposed rocks and beaches. After a yearlong gestation, females give birth to a pup usually about three days after arriving at the rookery. About two weeks after giving birth the mother mates. Most pups are nursed for a year, but in some cases are nursed for up to three years. Steller sea lions are opportunistic feeders, foraging mostly near the shore and over the continental shelf for fish, including walleye pollock, herring, capelin, mackerel, rockfish and salmon, and cephalopods such as squid and octopus.