Encyclopædia Britannica, Ninth Edition/Walrus

From Wikisource
Jump to navigation Jump to search
4244608Encyclopædia Britannica, Ninth Edition — WalrusWilliam Henry Flower

XXIV

WALRUS, or Morse.[1] In the article Mammalia (vol. xv. p. 442) it was shown that the existing members of the Pinniped division of the order Carnivora are divided into three very distinct groups, the true seals (Phocidæ), the sea-bears or eared seals (Otariidæ), and the Trichechidæ, containing the walrus alone, in some respects intermediate between the other two, but also possessing, especially in its greatly modified dentition, peculiar characters of its own.

Trichechus is the almost universally accepted generic name by which the walrus is known to zoologists, but lately some confusion has been introduced into literature by the revival of the nearly obsolete terms Rosmarus by some authors and Odobænus by others. T. rosmarus is the name of the species met with in the Arctic seas; that of the North Pacific, if distinct, is T. obesus. The following description will apply equally to both. A full-grown male walrus measures from ten to eleven feet from the nose to the end of the very short tail, and is a heavy, bulky animal, especially thick about the shoulders. The head is rounded, the eyes rather small, and there are no external ears. The muzzle is short and broad, with, on each side, a group of very stiff, bristly whiskers, which become stouter and shorter in old animals. The tail scarcely projects beyond the skin. The fore-limbs are free only from the elbow; the hand is broad, flat, and webbed, the five fingers being of nearly equal length, the first slightly the longest. Each finger has a small, flattened nail, situated on the dorsal surface at a considerable distance from the end. The hind-limbs are enclosed in the skin of the body almost to the heel. The free portion, when expanded, is fan-shaped, the two outer toes (first and fifth) being the longest, especially the latter. Cutaneous flaps project considerably beyond the bones of the toes. The nails of the first and fifth toes are minute and flattened; those of the second, third, and fourth elongated, sub-compressed, and pointed. The soles of both fore and

Walrus.
Walrus.

Walrus.

hind feet are bare, rough, and warty. The surface of the skin generally is covered with short, adpressed hair of a light, yellowish-brown colour, which, on the under parts of the body and base of the flippers, passes into dark reddish-brown or chestnut. In old animals the hair becomes more scanty, sometimes almost entirely disappearing, and the skin shows ample evidence of the rough life and pugnacious habits of the animal in the innumerable scars with which it is usually covered. It is everywhere more or less wrinkled, especially over the shoulders, where it is thrown into deep and heavy folds.

One of the most striking external characteristics of the walrus is the pair of tusks which descend almost directly downwards from the upper jaw, sometimes attaining a length, in old animals, of 20 inches, or even more. In the female they are as long or sometimes longer than in the male, but less massive. In the young of the first year they are not visible. These tusks correspond to the upper canine teeth of other mammals. All the other teeth, including the lower canines, are much alike—small, simple, and one-rooted, and with crowns, rounded at first, but wearing to a flat or concave surface. The complete dentition appears to be i 3/3, c 1/1, pm 4/4, m 1/0=9/8, total 34. Many of these teeth are, however, lost early, or remain through life in a rudimentary state concealed beneath the gum. The teeth which are usually functionally developed are i 1/0, c 1/1, pm 3/3=5/4 total 18. The tusks are formidable weapons of defence, but their principal use seems to be scraping and digging among the sand and shingle for the molluscs and crustaceans on which the walrus feeds. They are said also to aid in climbing up the slippery rocks and ledges of ice on which so much of the animal's life is passed. Although this function of the tusks is affirmed by numerous authors, some of whom appear to have had opportunities of actual observation, it is explicitly denied by Malmgren.

Walruses are more or less gregarious in their habits, being met with generally in companies or herds of various sizes. They are only found near the coast or on large masses of floating ice, and rarely far out in the open sea; and, though often moving from one part of their feeding ground to another, they have no regular seasonal migrations. Their young are born between the months of April and June, usually but one at a time, never more than two. Their strong affection for their young, and their sympathy for each other in times of danger, have been particularly noticed by all who have had the opportunity of observing them in their native haunts. When one of their number is wounded, the whole herd usually join in a concerted and intelligent defence. Although harmless and inoffensive when not molested, they exhibit considerable fierceness when attacked, using their great tusks with tremendous effect either on human enemies who come into too close quarters or on polar bears, the only other adversary they can meet with in their own natural territory. Their voice is a loud roaring, and can be heard at a great distance; it is described by Dr Kane as "something between the mooing of a cow and the deepest baying of a mastiff, very round and full, with its bark or detached notes repeated rather quickly seven or nine times in succession."

The principal food of the walrus consists of bivalved molluscs, especially Mya truncata and Saxicava rugosa, two species very abundant in the Arctic regions, which it digs up from the mud and sand in which they lie buried at the bottom of the sea by means of its tusks. It crushes and removes the shells by the aid of its grinding teeth and tongue, and swallows only the soft part of the animal. It also feeds on other molluscs, sand-worms, star-fishes, and shrimps. Portions of various kinds of algæ or sea-weeds have been found in its stomach, but whether swallowed intentionally or not is still doubtful.

The commercial products of the walrus are its oil, hide (used to manufacture harness and sole-leather and twisted into tiller ropes), and tusks. The ivory of the latter is, however, inferior in quality to that of the elephant. Its flesh forms an important article of food to the Eskimo and Tchuktchis. Of the coast tribes of the last-named people the walrus forms the chief means of support. "The flesh supplies them with food, the ivory tusks are made into implements used in the chase and for other domestic purposes, as well as affording a valuable article of barter, and the skin furnishes the material for covering their summer habitations, harness for their dog-teams, and lines for their fishing gear" (Scammon).

Geographically the walrus is confined to the northern circumpolar regions of the globe, extending apparently as far north as explorers have penetrated, but its southern range has been much restricted of late in consequence of the persecutions of man. On the Atlantic coast of America it was met with in the 16th century as low as the southern coast of Nova Scotia and in the last century was common in the Gulf of St Lawrence and on the shores of Labrador. It still inhabits the coast round Hudson's Bay, Davis Straits, and Greenland, where, however, its numbers are daily decreasing. It is not found on the Arctic coast of America between the 97th and 158th meridians. In Europe, occasional stragglers have reached the British Isles, and it was formerly abundant on the coasts of Finmark. It is rare in Iceland, but Spitzbergen, Nova Zembla, and the western part of the north coast of Siberia are still constant places of resort, in all of which a regular war of extermination is carried on. The North Pacific, including both sides of Behring's Strait, northern Kamchatka, Alaska, and the Pribyloff Islands are also the haunts of numerous walruses, which are isolated from those of the North Atlantic by the long stretches of coast, both of Siberia and North America, in which they do not occur. The Pacific walrus appears to be as large as, if not larger than, that of the Atlantic; its tusks are longer and more slender, and curved inwards; the whiskers are smaller, and the muzzle relatively deeper and broader. These and certain other minor differences have induced some naturalists to consider it specifically distinct under the name of Trichechus obesus. Its habits appear to be quite similar to those of the Atlantic form. Though formerly found in immense herds, it is rapidly becoming scarce, as the methods of destruction used by the American whalers, who have systematically entered upon its pursuit, are far more certain and deadly than those of the native Tchuktchis, to whom, as mentioned before, the walrus long afforded the principal means of subsistence.

Fossil remains of walruses and closely allied animals have been found in the United States, and in England, Belgium, and France, in deposits of Quaternary and late Tertiary age.

An exhaustive account of this animal, with references to all the authors who have written upon it, will be found in Allen's History of North American Pinnipeds, 1880. (w. h. f.)

  1. The former word is a modification of the Scandinavian vallross or hvalros ("whale-horse"), the latter an adaptation of the Russian name for the animal.