HABITS OF THE SEI WHALE
[Illustration:
“For many years the sei whale was supposed to be the young of either
the blue or the finback whale, and it was not until 1828 that it was
recognized by science as being a distinct species.”
]
For many years the sei whale was supposed to be the young of either the
blue or the finback whale, and it was not until 1828 that it was
recognized by science as being a distinct species. The Norwegians gave
the animal its name because it arrives upon the coast of Finmark with
the “_seje_,” or black codfish (_Polachius virens_), but in Japan it is
called iwashi kujira (_sardine whale_).
[Illustration:
A sei whale fast to the ship. The shape of the spout is well shown.
]
Until shore stations were erected in various parts of the world sei
whales were supposed to be very rare and were known only from the North
Atlantic Ocean, but within the last fifteen years they have been taken
near South Africa, the Falkland and South Shetland Islands, and Japan,
and have proved to be one of the most abundant of large cetaceans.
The sei whale has a roving disposition and wanders restlessly from one
coast to another, sometimes journeying great distances and suddenly
appearing in waters where it has never before been known. It has more or
less regular migrations and there is evidence that individuals travel
from the Antarctic into the North Atlantic and Pacific Oceans.
Strangely enough a clew to their wanderings has been given by a parasite
which lives upon the whale’s body. This Copepod, known as _Penella
antarctica_, produces a peculiar white or grayish oval scar two or three
inches in length, which for many years was supposed to be a feature of
the sei whale’s coloration. I suspected at first sight that these spots
were scars left by a parasite of some sort, but it was not until two
years later that my suspicion was proved correct and the animal itself
discovered.
It was doubly interesting to find that this parasite is an Antarctic
species which has never been known from the North Atlantic or Pacific
Ocean. On the second French Antarctic Expedition Dr. Liouville
discovered that all the sei whales taken in the South Atlantic were
bristling with these parasites but except in rare cases the whales of
the north have none of them _in situ_. The parasites are short-lived and
probably die or break off during the northward travels of their hosts,
leaving only the scars behind.
It is not probable that _all_ sei whales make this migration annually—in
fact it is highly improbable that such is the case—but herds are
apparently formed which visit certain localities every year, now and
then being reinforced by individuals which have come either from the
Antarctic into the north or vice versa.
[Illustration:
A blue whale, eighty-five feet long, at Kyuquot, Vancouver Island.
This is the largest animal that has lived upon the earth or in its
waters, so far as is known at the present time.
]
The migration of the large Cetacea is a subject about which very little
is known and of which but few positive statements can be made. In the
case of only one species, the California gray whale, can we tell exactly
where, when, and how far the animals travel, for this coast-loving whale
migrates as regularly as do birds and the paths of its wanderings are
known.
[Illustration:
“In the water the sei whale may be easily recognized at a considerable
distance by the form of the spout and the high dorsal fin which is
prominently displayed as the animal swims at the surface.”
]
In the water the sei whale may be easily recognized at a considerable
distance by the form of the spout and the high dorsal fin which is
prominently displayed as the animal swims at the surface.
This species does not dive very deeply and when feeding its movements
can usually be traced by the disturbed water, as well as by the clouds
of birds hovering about the tiny sea animals which come to the surface.
[Illustration:
“The sei whale has a roving disposition and wanders restlessly from
one coast to another, sometimes ... suddenly appearing in waters
where it has never before been known.”
]
In Norway the sei whale feeds upon the small red shrimp (_Euphausia_)
and an exceedingly minute crustacean known as “Aate” (_Calanus
finmarchius_); in Japan only three or four individuals which I examined
during 1910 had anything but shrimp in their stomachs, although the
natives say that sardines are often eaten, and call this species the
sardine whale.
All the gunners assert that the sei whale can reach a greater speed in
its first rush after being harpooned than any other large cetacean, and
I have seen animals which were not killed at once dash off like a hooked
bluefish. But the first wild rush is soon ended and the whale is
generally easily killed because it does not have the strength and
staying power of its larger relatives, the finback and the blue whale.
On land the African hunting leopard, or cheetah (_Acinomyx jubatus_),
parallels the sei whale, and for a few hundred yards can probably
distance any other animal, although it too soon tires if the chase is
long.