Southern right whale with her calve. |
These intelligent and inquisitive animals are seen from along
the shores of the southern tip of Africa. Southern right whales are one of
three endangered species belonging to the genus Eubalanea. Considered a marine
mammal, because of giving birth to live young, producing milk for their calves,
being warm blooded and breathing air, these enormous animals can weigh as much
as 8 fully grown African elephants and reach 16 metres in length.
The southern right whale, like other right whales, have callosities that
appear white due to colonies of cyamids (whale lice) and barnacles. Dark grey
or black in colour, these giant
marine animals are without a dorsal fin but are able to swim by using their short
and wide pectoral fins that aid in steering while their rear flukes propel them
forward through the ocean. They have a long and arching mouth that begins above
their eye, adding character to their gigantic profile.
Habitat
The southern right whale migrates to the coastal waters of
South Africa, in the winter months and can be seen from the shore in False Bay,
between June to October. These magnificent marine mammals form small social
groups of about six individual and related whales. Whales have a strong
maternal connection to the locations they were born in and are known to return
to these very locations every 3 years.
Arched mouth showing baleen plates. |
Diet
Whales usually search for food on the surface of water but will on occasion
dive for food. They mostly eat small plankton called copepods but also indulge
in krill, mysids, plankton and other tiny crustaceans.
They do not possess teeth and instead have around 200 long baleen plates
hanging from their upper jaw. These plates can reach over 2 metres in length and
have a fringe of hair running down each side. As a whale swims along the
surface of water into swarms of plankton they open their mouth in order to
catch their food and then close their mouth, using their tongue to push the
water out between the baleen plates while keeping their food in their mouth.
Behaviour
Southern right whales are wonderful animals that are social
with other whales and dolphins and even enjoy interacting with humans. They
seem aware of their enormous size and so are gentle with their movements when
around humans and smaller animals of the sea. These whales are more active than
the other two northern species of right whales and are known to approach boats
out of curiosity.
Breaching in False Bay. |
Whales engage in a variety of behaviour in the water for play
or as a form of a communication. Sailing is
playful behaviour exclusive to southern right whales, usually seen off the
coast of Argentina and South Africa, who use their raised flukes to catch the
wind. The normal breathing pattern of a whale is referred to as blowing which involves making a sound by expelling air through their blowhole
accompanied by a spray of water vapour. Lob-tailing
is a form of communication used by whales and is the slapping of water
using their flukes and tail in order to make a loud sound. Whales lift their
heads and body vertically above the surface as water, known as spy-hopping, so as to see what is happening
above water. Breaching is when a
whale leaps out of the water in a back flip landing on either their side or
back.
Reproduction
Being polyamorous by nature, female whales mate with up to 7
males during the breeding season from July to October and return the following year to give birth to a single calve. Males do not fight amongst
one another or experience feelings of jealousy when it comes to pairing up with
females for mating.
The female whales work on a 3-year cycle
which includes one year of carrying a calve, a year taking care of their
new-born and one year recovering and rebuilding their food reserves before
starting the cycle once again.
Calves are usually born a dark-bluish
colour but in some cases, about 4% of calves are born white. Due to a
sex-linked genetic trait, all the calves born white are male and their colour
darkens with age.
Did you know?
Whales can produce a variety of low frequency sounds (less
than 1 000 Hz) to communicate with other whales. These sounds are made up of
moans, growls, pulses and belch like noises.
No comments :
Post a Comment