The bearded seal (Erignathus barbatus) is the largest true seal normally found in the seas adjacent to Alaska. It inhabits areas of the Bering, Chukchi, and Beaufort seas where sea ice forms during the winter.
Eskimos who speak the Yupik language refer to this seal as mukluk, and Inupik-speaking Eskimos call it oogruk. Oogruk is the most common name. These general names are not used when reference is made to bearded seals of certain age groups or seals engaged in characteristic activities. For example, a young oogruk is called oogruarokh; an oogruk hauled out on the ice is called kamugituk.
The term mukluk has, apparently by accident, come to mean a certain type of footwear made of skins. The story was told that when white men first came to western Alaska, someone asked a local resident what he was wearing on his feet. The Eskimo, thinking he was being asked what his boots were made from, said that they were mukluk (meaning from a bearded seal). Today almost all types of eskimo-made footwear are called mukluks.
General Description: Bearded seals are heaviest during winter and early spring when they may attain a weight of more than 750 pounds (341 kg). From June through September adults usually weigh from 475 to 525 pounds (216-239 kg). This seasonal loss of weight results from decreased feeding during spring and summer and is most obvious in changes of the thick layer of blubber under the skin. Measured from nose to tip of tail (not including hind flippers), adults average about 93 inches (2.4 m). Color varies from a tawny-brown or silver-gray to dark brown. Unlike other Alaska seals, adult bearded seals have neither spots nor bands. They have comparatively long whiskers (mystacial vibrissae), rounded foreflippers of which the middle one of the five digits is longest, relatively small eyes, and four mammary teats rather than two as on other Alaska seals. Bearded seals normally have 34 teeth—six incisors on the upper jaw and four on the lower, two canines upper and lower, eight postcanines on upper and eight lower, and two molars on the upper and two on the lower jaw. Teeth are small and their wear is rapid; most bearded seals older than 9 years appear toothless, although roots persist beneath the gum line.
Life history: Females bear a single pup, usually during late April or early May. The average weight of pups at birth is around 75 pounds (34 kg), and average length is about 52 inches (1.3 m). By the end of a brief nursing period lasting from 12 to 18 days, pups increase their weight almost three times, to around 190 pounds (86 kg). This gain is due mainly to an increase in thickness of the blubber layer.
Most females breed again within two weeks after their pup has been weaned. Embryonic development is delayed for 2½ months after conception, until mid- to late July when implantation occurs and the embryo begins to develop rapidly. The reproductive cycle is annual and the gestation period is about 11 months, including the period of delayed implantation.
Some female bearded seals begin to ovulate at 3 years of age, but reproductive maturity (the ability to conceive successfully) is not attained until they are 5 or 6 years old. Males become sexually mature at 6 or 7 years. Bearded seals commonly become reproductively active before they attain maximum growth. The incidence of pregnancy in adult females is about 85 percent, and the sex ratio of Alaska samples consistently shows slightly more females in the population.
Food habits: Bearded seals eat a wide variety of invertebrates and some fishes found in and on the rich bottom of the shallow Bering and Chukchi seas. The main food items are crabs, shrimp, clams and snails.
Seasonal movements and distribution: Bearded seals usually are solitary animals. They make seasonal migrations as they follow the movement of sea ice. The density of animals in a given area varies widely. In late winter, when ice occupies a large area of the northern seas, bearded seals are widely dispersed. During their northward spring migration through the constricted waters of Bering Strait and during late summer when sea ice has receded to the Arctic Ocean they are more concentrated. Adult bearded seals are almost always associated with ice, but young seals sometimes remain in ice-free areas where they frequent bays and estuaries.
Behavior: Bearded seals vary in their alertness or wariness depending upon the time of year. In the spring when they are basking on the ice, bearded seals frequently show little concern about the presence of a boat or humans. One might judge that this seal's senses of sight, smell, and hearing are very poor. In fact, bearded seals have good vision and hearing, and at least a fair sense of smell. During late fall when boats are used in the hunt, it is common to see a bearded seal surface several hundred yards from a boat, trying hard to identify the source of disturbance. During winter hunts on the ice, the slightest sound of a hunter will cause a seal to flee amidst a mighty splash of water. A hunter must remain well hidden, and if exposed, move very slowly so as not to alarm the seal. It is a common occurrence to see a bearded seal surface, immediately dive and resurface far out of effective rifle range, obviously aware of something strange in the vicinity.
Judging by the number of freshly scarred adults taken by hunters during May and June, fighting is very common during the breeding season. With imagination, it is easy to misinterpret the cause of these wounds and attribute them to a bearded seal's desperate struggle to escape from the grasp of a polar bear. Polar bears do eat bearded seals, but the number of bears present in central Bering Sea is relatively small, while the incidence of adults with fresh scars during the spring is high.
During April, adult male bearded seals begin underwater “singing.” The song is a highly characteristic and complex frequency-modulated whistle, parts of which are audible to humans. Hunters are sometimes guided to a seal by its whistle. Singing males are designated by the Eskimo word au-uk-touk.
Hunting: Residents of western coastal villages depend upon bearded seals and other seals for hides and a large part of their food. Bearded seal meat is the most desirable of the seals, and the hides are necessary for boat covers, raw-hide line, boot soles, and numerous other uses. Bearded seals are hunted whenever they are available. Spring hunts (which coincide with the northern migration of seals) are the most successful. In the spring, boats can be used to hunt in the loose drifting ice. Productive bearded seal hunting begins during late April in the northern Bering Sea area and is progressively later at the more northerly villages.
Text: John J. Burns
Illustration: R.T. Wallen
Revised and reprinted 1994
