African Penguins
From the desk of Van the
PENGUIN Man
Specialist Tourist Guide: 5113
ABOUT THE AFRICAN PENGUIN
The African Penguin is endemic to South African waters. They
are found on 24 islands around Southern Africa, from Namibia to St. Croy island at Port
Elizabeth but nowhere else in the world.
There are three mainland colonies; Simon's Town, Betty's Bay and Namibia. The African
Penguin is a cause for concern as it is listed in the Red Data Book as an endangered
species. There were once more than 1.2 million in number in 1930 but by the end of 1980's
there were less than 200,000.
To many, the Jackass, blackfooted or African Penguin Spheniscus Demerus is a cute little
bird, beloved of cartoonists and refrigerator advertisements.
Without the penguin however, South Africa as we know it would be quite different. In the
early days of the establishment of the fort at Cape Town, the penguins killed at
Robben-Island colony in Table Bay kept the Dutch from starving. Since the settlement was
originally founded to provide provisions to passing ships of the Dutch East India Company,
the company would probably not have bothered with attempting to re-establish that, that
could not even feed itself.
While the settlement survived, the penguin colony at Robben-Island did not, being reduced
from a million to none in just a few decades.
FLYING UNDERWATER
Penguins are clumsy on land but in the water they are expert divers with great speed and
agility. Penguins are expert swimmers. They use their flippers with more skill in under
water, water mobility then their rivals, the seal and dolphin. In a sense, it can be said
that they exchanged the ability of "flying in the air" to "flying under
water." Penguins swim at an average speed of about 7km/h to about 24km/h and for 2
and a half minutes under water before they need to come up for air.
PENGUIN PLUMAGE
The difference between the sexes is noticeably the size of
the beak. The male has a longer and broader beak than that of the female.
The throat are separated from the crown and nape by a sharply defined white line, the
black continues over the back and flippers down the tail. The breast and belly are white
with black spots (their finger prints). A sharply defined black line forms a "horse
shoe" or inverted crescent on the chest which extends down both sides of the chest
and belly to the lower abdomen.
Chicks are covered in a soft gray downy plumage, until they are about 3 months old and
Juveniles have black upper plumage and plain under plumage.
REASONS FOR THEIR DECLINE
- The harvesting by man of guano (bird droppings), which is a
hardish substance sometimes meters thick, in which the penguins make burrows to make their
nests.
- The harvesting of penguin eggs for human consumption from the
1920's to the 1960's
- The destruction of their foot supply by over-fishing.
- Diseases such as (Newcastle disease and Avian Malaria).
The greatest threat however, is the danger of oil pollution
from tankers illegally cleaning their tanks as they round the Cape to the Middle east, or
by sinking ships,
The oil destroys the insulating ability of the feathers and the birds eventually die of
exposure. In 1968, two accidents involving oil tankers caused the deaths of approximately
25,000 penguins. During the 1994 Apollo sea disaster. l0 000 penguins were oiled. Cape
Nature Conservation and SANCCOB managed to rescue, clean and rinse 4,500 penguins, which
were later released. About 3,000 of these were from Dassen Island and it appears that more
than 1,200 of these oiled penguins have returned to this island. This may be one of the
world's most successful oiled sea-bird rescue operations.
From the early 1970's SANCCOB (South African National Foundation for the Conservation of
Coastal Birds) started releasing rehabilitated penguins on Robben Island, mostly victims
of oil spills that had been cleaned. In 1983 after almost 3,000 penguins had been released
on the Island, they began breeding again. Only nine breeding pairs were counted in that
year but the numbers increased rapidly and in 1990 a maximum count of 1,238 active nest
sites was obtained. Moult counts indicated that the island was home to about 3,800
penguins, this means that in a relatively short period the island has become the worlds
seventh most important breeding locality for African Penguins. There is uncertainty about
the extent the release of rehabilitated birds played in reestablishing the island as a
breeding colony. Very few birds that breed on the island have been handled by SANCCOB.
However regular presence of penguins on and around the island may have attracted birds
from elsewhere. The rate of increase is so rapid that continued immigration of penguins to
the island takes place.
Sightings of banded birds indicate that they arrive from as far afield as Malgas, Dassen
and Dyer Islands as well as from Stony Point. Penguins on Robben Island are now readily
visible and have proved popular with tourists, more than 27,000 people viewed the penguins
in 1989. A section of the island, which contains about 70% of the penguin breeding
population is soon to be declared a nature reserve for seabirds. In view of these positive
trends the 21st century may prove to be a new highlight in the history of the African
Penguin. Boulders Beach itself has 2,600 penguins.
PENGUIN BREEDING
Penguins breed throughout the year, with each pair producing one clutch annually. Nests
are lined with feathers or any material that is suitable.
One or two white eggs are laid, the size being approx. 7.2cm x 5.56cm and weigh about
107grm.
Both parents take turns to sit on the eggs and the incubation period is 38 to 42 days.
Penguins start to breed from between three to four years of age.
Penguins moult once a year, before moulting, penguins build up their fat reserves to last
for this entire moulting period (three weeks).
The Jackass penguin (as the African penguin is known)
derives its name from the call it makes - a loud braying similar to that of a donkey.
An average diving depth of 35m to 100m can be obtained and
last for the duration of between 71 and 195 seconds.
PENGUIN DIET
Their food consist of anchovy sardines, squid and sancord (an eel like fish. ) Chicks
consume an average of 25kg of fish until they reach fledging stage.
Adults consume an average of 540grm, of fish a day.
Their Chicks are fed regurgitated food by their parents until they can go to sea
themselves. During breeding time, the penguin's hunting range is 3,945km. Non-breeders can
hunt as far as 102km away. Parents teach their voung to swim at the age of about 3 months.
As recently as 1980, biologists thought they understood the
problems facing the penguins in South Africa. Egging and direct human exploitation were
illegal and minimal. Oiling was an occasional problem but rehabilitation efforts were
highly successful for penguins that reached cleaning facilities.
The great concern was over commercial fishing. The penguins depend on the Cape Anchovy
(Entrails Capensis) for 80% of its prey, yet the commercial fishery was believed to take
up to 60% of the total anchovy population of South Africa some 600.000 tones. It appeared
that penguins were suffering from a shortage of food. Penguins at the west coast breeding
colonies were observed, for long periods away from their nests, so that mates were forced
to desert. Growth rates of the young in the wild are much slower than those of captive
birds, finally, the population was believed to have decreased sharply, based on estimates
in 1956 and 1978 from 236,000 to 100,000 birds.
Penguins and fisheries appeared to be competing for food, with industry being the winner.
Unless some means could be found to increase the food available for the west coast
penguins their population was likely to continue to decrease. In 1983, Sea Fisheries
Research Institute scientists, using sophisticated acoustic sampling devices on board the
new research vessel, Africa, found a large anchovy population on the South coast.
The population was at least twice as large as previously thought, therefore the fishing
industry was only taking 25% of the total, instead of the 60% previously believed.
Could the industry really be over-exploiting the South African anchovy under such
conditions? If there was so much Anchovy why were penguins declining? To answer these
questions, we need to review a bit of anchovy biology.
The Traditional view has been that adult anchovy spawn their eggs on the south coast, to
the east of Cape Point and the eggs and Larvae are transported northwards around the point
by fast moving "jet" current which eventually deposits them in a nursery"
in the rich and relatively sheltered waters of St. Helena Bay. The young grow rapidly in
these conditions and are nearly adult size by winter. They then move south to join the
spawning population.
Until recently, the anchovy on the south coast were believed to range from one to four
years old, only recently have scientists learned that anchovy grow more rapidly than
previously believed, so that most anchovy are less than two years old. The population
turns over more rapidly with young anchovy represcnting a much larger part of the
population than previously believed. Why then has the number of Jackass penguins decreased
so dramatically
Early in the 20th century large numbers of eggs were harvested for human use.
More recently penguins have to compete with commercial fisheries for food.
They have been victims of spills, displaced from breeding sites by a burgeoning seal
population, and their Chicks have been preyed upon by feral cats introduced to some
islands were they breed.
These factors have resulted in higher than normal mortality rates throughout the penguins
life span from the eggs to chicks, through to immature birds and adults, as well as
reduced reproductive output. Taking all these factors into consideration, the impact has
been enormous.
MORE ABOUT PENGUINS
The pink patch above the eye is the sweat gland, the darker
it becomes the hotter the penguin feels. There is salt-water gland that is situated in the
head; this purifies the salt water that the penguin drinks, they then sneeze out the salt
crystals. A transparent film moves over the eyes the moment the penguin dives. The ears
are protected by an oil which is secreted. The feathers which overlap one another are
entirely waterproof. Penguin males weigh about 3.6 kg and females 3.1kg. They moult once a
year between November and March, during this period of three weeks, they remain ashore, as
they cannot swim, therefore they don't eat either.
The ability to withstand intense cold is one of the
penguin's greatest assets. Most penguins have rather small feet, wings and heads, the
relatively little surface area in comparison to the birds volume results in excellent heat
conservation. In addition, many penguins have a thick layer of fat under the skin. Some
species are better equipped for cold weather than others. The Emperor penguin which may
weigh 27 to 30kg (60-701bs.) appears to be best equipped of all.
ENEMIES OF THE PENGUINS AND THEIR CAMOUFLAGE
Natural enemies in the water are: Sharks, Seals, Octupi and
kelp. Enemies on land are: Man, Cape Clawless Otter,Spotted Genet, Seagull and Mongoose.
They have a protective camouflage for the sea, with a black back and white front. When an
enemy approaches from below, it can not easily distinguish between the white belly and the
colour of the sky. In converse, if the predator approaches from above, it will only see
the darkness of the deep blue sea.
MORE INTERESTING FACTS
Always move slowly. Do not run, shout or make sudden
gestures when close to the birds. Be gentle and you should be rewarded by a calm bird and
a wonderful experience with nature. A sign of stress is the sideways movement of the head,
they appear to be inquisitive but are actually adopting an aggressive attitude.
WHAT ROLE PENGUINS PLAY
Today I would suggest that the penguin still has an important role to play in South
Africa's future. It represents a "canary in the cage" monitoring the health of
the marine environment.
If we can under stand the ecology of the Jackass penguin and successfully conserve its
population, we will be well along the road to conserving the renewable riving resources of
South Africa's coastal waters.
OTHER FACTS
The Large Emperor Penguins dive as deep as 250m (820 ft) and
can stay under water for as long as 20min. Adelies can dive down to 60m (over 190ft).
To help them keep warm, penguins have a thick waterproof plumage, beneath the outer
feathers is a layer of down. This traps warm air next to the skin like a woolen vest.
Penguins also have a layer of fat under the skin which helps keep out the cold. The
Emperor penguin breeds in one of the world's most inhospitable regions during one of the
coldest periods of the year, laying and incubating its eggs in temperatures as low as
-62°c(-80°F).
WHAT PART CAN YOU PLAY?
Offer your services to SANCCOB as a volunteer to help clean
and feed oiled or injured penguins and other sea-birds.
Take oiled sea-birds to SANCCOB. (Be careful of the sharp beaks and claws). If you are
unable to transport the bird yourself, please contact any of the following:
S.A.N.C.C.O.B.------------------------(021) 557-6155/6
Mr. or Mrs. Campbell----------------(021) 557-5203
Mr. Waterrneyer----------------------(021) 557-9080
Mr. v.d. Merwe----------------- ------(021) 786-1707
S.A.A.N.C.O.B Address:
The Secretary,
SANCCOB.
P.O. Box 11-116
Bloubergrant
7441
South Africa.
VAN THE PENGUIN MAN
Lectures, guided tours by appointment
At Boulders Jackass Penguin Colony
Simon's Town.
Simon's Bay South Africa
Cell Phones: 083-212-1275 or 082-921-5724
e-mail: van@bouldersbeach.co.za
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