
Whale
watching at Albatross House
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The
False Bay Whales
Several species of whale come into False Bay and can be seen in the
vicinity of Simon's Town. These include Bryde's Whale, the Humpback Whale
(which is the one that 'Sings') and the Killer Whale, more commonly known
as the Orca. By for the most common, however, is the Southern Right Whale,
which visits us from June to December.
Southern
Right Whales
Scientific
Name and Statistics
Scientific
Name: Eubalaena Australis [eu = Greek, right;
balaena = Latin, whale; australis = Latin, south]
Family: Balaenidae
Statistics: Adult
females, larger than the males, are on average 15 meters long and weigh about
40-45 tons, while the males are a little smaller at 14 meters.
Description
The term "right" whale
refers to the fact that in the nineteenth century these whales were
regarded as the "right" whales to catch, because they were particularly
rich in oil. Being slow swimmers they were easy to catch, and because
their carcasses were easy to handle as they floated when dead. It
is usually considered that there are two species of "right"
whales, one in the Northern Hemisphere and the other in the
Southern Hemisphere.
Southern
Right whales are baleen whales. This mean that they have about
200 to 270 pairs of fine 'plates' which hang down from the upper
jaw like vertical venetian blinds, through which they filter their
food [see under Diet]. These plates may be up to 3 meters (9.5
feet) long.
The
most striking feature of the Southern Right whales are the 'callosities'
(horny growths) behind the blowholes, and on the face. These provide
homes for several other creatures, including the 'whale lice' or
cyamids, which live on the callosities and operate in a symbiotic
relationship with the whales, feeding off the dead skin. Barnacles
called Tubercinella Major, burrow 4 cm down into the skin. The
other characteristic, which distinguishes the Southern Right whales,
is their V-shaped blows. Southern-Right whales are black or dark
grey in colour. They have no dorsal fin. They have large, bow-shaped
heads and arched mouths. Unusually, Southern Right whales are relatively
hairy with up to 300 hairs on the tip of the lower jaw and about
100 on the upper jaw.
Southern
Right whales can remain under water for about 6 minutes and swim
fairly slowly at an average speed of 6 kilometers and hour when
cruising, although than can reach 11 kilometers-an-hour in short-bursts.
Although
the humpback whales are the best "singers", Southern Rights do
produce low frequency sounds to communicate with one another.
The
life span of the Southern Right whale is not established, but it
is believed that they can live for over 50 years.
Range & Habitat
The
Southern Right Whale lives between latitudes 20 ° to 55 °,
occasionally venturing down to 63 °. Although it is to be found
throughout the southern oceans, in our part of the world it returns
annually to the sheltered bays of the Southern African coast in order
to breed and give birth. In False Bay it can be seen between June
and December. It is most prolific close to the shore from about September,
and it is occasionally seen out of season, as early as May or as
late as January. During the summer months the Southern Right whales
move south to the cold and stormy waters of the Antarctic where it
feeds.
Diet
As baleen whales, right whales swim with their mouths open so that
the baleen plates can filter out the water and retain the krill,
which forms a large part of their diet. They eat up to 11 tons
a day of these tiny creatures. They are seasonal feeders, eating
in winter and living off their blubber in the breeding months
in the north.
Reproduction
One female, Southern Right whale will mate with a number of males
at the same time, with sometimes as many as eight competing for
her favour. The male producing the most sperm is probably the father
of her baby. Females usually have one calf every three years. The
gestation period (pregnancy) of the Southern Right whale is twelve
months, she bears her calf in the spring in the warmer waters of
Southern African bays. Usually only one calf is born although twins
sometimes occur. About 3% of calves are born white, but this usually
becomes grey after a few months. The calf is born tail first and
immediately swims to the surface of the water to take its first
breath. Initially the mother helps it but within thirty minutes
of birth it can swim. The newborn calf is about 4.5 to 5 meters
long. The calf suckles from a pair of teats, sometimes consuming
600 liters of milk a day and growing 2.8 cm a day. It is weaned
after about 6-8 months by which time it has reached about 9 meters
in length.
Conservation
Southern Right whales are regarded as an endangered species as
their numbers have been considerably reduced in the last 200
years. Between 1790 and 1825 it is estimated that over 12 000
Southern Rights were killed by whalers of the South African coast.
Now collisions with ships or entanglement in fishing gear are
the main dangers. There are now about 4500 Southern Right whales,
with about 1500 coming to Southern Africa. However, Southern
Rights are not as vulnerable as the Northern Rights, which are
believed to be close to extinction, since they live in more hazardous
waters. Moreover, Southern Rights are increasing in number, doubling
in size every ten years, which means that they should have returned
to their optimum population size in about 2040.
In
1980 and again in 1984 legislation was introduced in South Africa
to protect whales. It is now illegal to shoot at whales, or harass
them by coming closer than 300 meters in any craft. |