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Jackass Penguins (South Africa) | by |kris|
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Jackass Penguins (South Africa)

The African penguin or black-footed penguin (Spheniscus demersus) is only found on the south-western coast of Africa, living in colonies in Namibia and South Africa. It is the only penguin species that breeds in Africa. It is also widely known as "jackass" penguin for its donkey-like bray, although several related South American penguins species produce the same sound. Like all extant penguins it is flightless, with a streamlined body, and wings stiffened and flattened into flippers for a marine habitat. Once extremely numerous, the African penguin is declining due to a combination of threats and is classified as endangered.

 

TAXONOMY

The African penguin is a banded penguin. The other banded penguins are the African penguin's closest relatives, and are all found mainly in the Southern Hemisphere: the Humboldt penguin and Magellanic penguins found in southern South America, and the Galápagos penguin found in the Pacific Ocean near the equator. All are similar in shape, colour and behaviour.

The Spheniscus genus to which the African penguin belongs to derives from the Ancient Greek word sphen, which means wedge. This refers to their streamlined body shape. Its species name, demersus, is a Latin word for "plunging".

 

DESCRIPTION

The African penguin has distinctive pink patches of skin above the eyes and a black facial mask; the body upperparts are black and sharply delineated from the white underparts, which are spotted and marked with a black band. The pattern of spots on the chest is unique for every penguin, like human fingerprints. Adults grow to 60–70 cm tall and weigh on average between 2.2–3.5 kg. The males are larger than the females and have larger beaks. Juveniles do not possess the bold, delineated markings of the adult but instead have dark upperparts that vary from greyish-blue to brown; the pale underparts lack both spots and the band.

The pink glands above their eyes are used for thermoregulation to help them to cope with changing temperatures. When the temperature gets hotter, the body of the African penguin sends more blood to these glands to be cooled by the air surrounding it. This then causes the gland to turn a darker shade of pink.

Their distinctive black and white colouring is a vital form of camouflage called countershading: white for underwater predators looking upwards and black for predators looking down onto the dark water.

 

POPULATION

Roughly 4 million penguins existed at the beginning of the 19th century. African penguin populations, have declined by 95% since pre-industrial times. In 2010, the number was estimated to be only at 55,000. If this decline is not halted, the African penguin is expected to be extinct within 15 years. In November 2013 the African penguin was listed as endangered on the IUCN Red List of Threatened Species.

 

BREEDING

The monogamous African penguin breeds in colonies, and pairs return to the same site each year. The African penguin has an extended breeding season, with nesting usually peaking from March to May in South Africa, and November and December in Namibia. A clutch of 2 eggs is laid either in burrows dug in guano, or scrapes in the sand under boulders or bushes. Incubation is undertaken equally by both parents for about 40 days. At least one parent guards the chicks until about 30 days, whereafter the chick joins a crèche with other chicks, and both parents head out to sea to forage each day.

Chicks fledge at 60 to 130 days, the timing depending on environmental factors such as quality and availability of food. The fledged chick then go to sea on their own and return to their natal colony after a lengthy time period of 12–22 months to molt into adult plumage.

When penguins molt, they are unable to forage as their new feathers are not waterproof yet; therefore they fast over the entire molting period, which in African penguins takes about 20 days.

 

THREATS

- Predation: The average lifespan of an African penguin is 10 to 27 years in the wild, and can live up to 30 in captivity. However, the African penguin may often fall to predators. Predators in the ocean include sharks, Cape fur seals and, on occasion, orcas. Land-based enemies include mongooses, genets, caracals, domestic cats, and the kelp gull which steals their eggs and newborn chicks.

- Commercial fisheries have forced these penguins to search for prey farther off shore, as well as making them eat less nutritious prey, since their preferred prey has become scarce. Global climate change is also affecting these penguins' prey abundance.

- As recently as the mid-20th century, penguin eggs were considered a delicacy and were still being collected for sale. Unfortunately, the practice was to smash eggs found a few days prior to gathering, to ensure that only fresh ones were sold. This added to the drastic decline of the penguin population around the Cape coast, a decline which was hastened by the removal of guano from islands for use as fertiliser, eliminating the burrowing material used by penguins.

- Penguins remain susceptible to pollution of their habitat by petrochemicals from (oil) spills, shipwrecks and cleaning of tankers while at sea.

- Due to the positive outcome of African penguins being raised in captivity after tragedies, such as the Treasure oil spill, the species is considered a good "candidate for a captive-breeding programme which aims to release offspring into the wild"; however, worries about the spread of new strains of avian malaria is a major concerning factor in the situation.

 

CONSERVATION

Many organisations such as SANCCOB, Dyer Island Conservation Trust, SAMREC and Raggy Charters are working to halt the decline of the African penguin. Measures include monitoring population trends, hand-rearing and releasing abandoned chicks, establishing artificial nests and proclaiming marine reserves in which fishing is prohibited. Some colonies (e.g. on Dyer Island) are suspected to be under heavy pressure from predation by Cape fur seals and may benefit from the culling of individual problem animals which has been found effective in trials.

Source: Wikipedia

 

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Taken on October 27, 2008