The strange-looking animal commonly known as the narwhal (Monodon
vnonoceros) differs from all other members of the family by the enormous
spirally twisted tusk projecting from one side of the upper jaw of the male.
This tusk is nearly always that of the left side, its fellow on the opposite
side being only a few inches in length, and lying entirely concealed within the
bone of the jaw, while in the females both tusks remain in a similar rudimentary
condition. The developed tusk of the male is composed solely of ivory, and its
spiral twist always runs from left to right. In form it is cylindrical, and
tapers more or less markedly from root to tip. Not infrequently the tusk attains
a length of from 7 to 8 feet, or more than half that of the entire animal. Very
rarely narwhals are met with in which the right tusk is developed as well as the
left, but there appears to be no known instance of the right tusk being
developed while the left remains rudimentary; and it is noteworthy that when the
right tusk is developed it has the same left-to-right twist as its fellow. A
fine narwhal's skull with two tusks is preserved in the Cambridge Museum. Apart
from a few small rudimentary ones, which are irregular in their occurrence, the
male narwhal has no teeth except the tusk, while the female—save for similar
rudiments—is toothless.
Although the presence of the tusk in the male narwhal, and the practically
toothless condition of the female, are alone sufficient to distinguish the genus
from all other dolphins, it is necessary to say something further regarding the
form and structure of this singular animal. In the first place, the narwhal
belongs to a group of dolphins characterized by their blunt and rounded heads,
in which the muzzle shows no sign of being produced into a beak. A special
character of the animal is to be found in the absence of a back-fin, which is
represented merely by a low- and ill-defined ridge. The flippers are short,
wide, and rounded. In color the narwhal is dark grey or dusky above and white
beneath, the back and sides being irregularly mottled with various shades of
grey. The entire length may vary from 12 to about 16 feet. A tusk measuring 8
feet in length had a basal girth of 71 inches.
The narwhal resembles the Greenland whale in being an inhabitant of the icy
polar seas, and like that species is circumpolar in its
distribution; it is, however, apparently local in its range, being, according to
Captain Scammon, but rarely found in the seas accessible to the whalers who pass
through the Behring Strait. Although seldom occurring to the south of the 65th
parallel of north latitude, there are three instances (one in 1648, a second in
1800, and a third eight years later) of narwhals visiting the British coasts.
From the extreme rarity of such occurrences, there is, however, no doubt that
the individuals in question had been carried by currents out of their proper
habitat. From constant persecution, the numbers of the narwhal have been greatly
reduced in the more accessible portions of its habitat; and according to Baron
Noidenskiold, it is now never seen on the coasts of Novaia Zemlia. It is,
however, more common at Hope Island, and large herds are reported from the seas
between Spitzbergen and Novaia Zemlia. It is noteworthy that fossil remains of
the narwhal have been found in the so-called forest-bed of the Norfolk coast,—a
deposit laid down before the great cold of the glacial period, but when the
temperature may have been steadily lowering, whereby Arctic animals were enabled
to leave their more northerly haunts.
Of the habits of narwhals, unfortunately very little is known. They are
generally found in small schools, comprising from fifteen to twenty individuals;
and were described long ago by Scoresby as. being extremely playful in their
disposition. Much has been written as to the use of the characteristic tusk, but
nothing very definite has yet been ascertained with regard to it. That it is not
employed for the purpose of procuring food, is perfectly evident from the fact
of its absence in the female. A more probable suggestion is that it is used by
the males in combats among themselves for the possession of the females; in
which case it should be regarded as a sexual appendage, analogous to the antlers
of the deer. The food of the animal is stated to be mainly composed of cuttles
and various crustaceans, together with small fishes. As a rule, but a single
young is produced at a birth, but an instance of twins is on record.
The narwhal is valued both for its ivory and its oil; the latter products being
of superior quality to ordinary whale-oil. The ivory of the tusk is very dense
in structure, and of a pure creamy-white colour; but since the tusk is hollow
throughout the greater part of its length, its value is much less than it would
be otherwise. The price of narwhal tusks, although very variable is, however,
considerable.