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Friday, February 13, 2009

Spheniscus demersus (The African Penguin)








Facts

Also known as: jackass penguin
Kingdom Animalia
Phylum Chordata
Class Aves
Order Sphenisciformes
Family Spheniscidae
Genus Spheniscus (1)
Size Length: 60 - 70 cm (2)

Status

Classified as Vulnerable (VU) on the IUCN Red List 2007 (1). Listed on Appendix II of CITES (3), and Appendix II of the Convention on Migratory Species (CMS or Bonn Convention) (4).

Description

The African penguin is a medium-sized penguin, and the only species breeding on the African continent (5). Penguins have a robust, heavyset body and this species are black on the back and white below, with variable black markings on the breast and belly (2). Juvenile plumage is slate blue on the upper surface and this gradually turns darker, developing the adult black-and-white facial pattern in the second or third year. Penguins have small muscles at the base of each feather that enable them to be held tightly against the body whilst in water, forming a waterproof layer; alternatively, on land they are held erect, trapping an insulating layer of air around the body (5). These penguins are also known as ‘jackass penguins' due to their loud, braying call (6).


Range


Found in southern Africa, these penguins are known to breed on 24 islands between Hollamsbird Island, Namibia and Bird Island in Algoa Bay, South Africa (2).
UNEP World Conservation Monitoring Centre View a distribution map for this species at UNEP World Conservation Monitoring Centre.
Habitat

African penguins are generally found within 40 kilometres of the coast, emerging onto rocky offshore islands to breed, rest and moult (2).

Biology

African penguins are colonial breeders with pairs returning to the same site year after year. Unusually, there is no fixed breeding season although nesting peaks in Namibia between November and December and in South Africa between March and May. Nests are situated in burrows or depressions under boulders and bushes where they will receive some protection from the potentially harsh temperatures (5). The clutch size is usually two and both parents take it in turns to incubate the eggs for a period of about 40 days; penguins have a bare patch of skin on the lower abdomen (known as the ‘brood patch'), which allows greater transfer of heat to the eggs. Following hatching, the adults will continue to guard the chicks until they are about 30 days old, regurgitating food straight from their stomach following foraging trips. Chicks are then left alone in crèches whilst their parents forage; at between 60 and 130 days old they develop juvenile plumage and leave the colony (5).

These penguins feed on fish such as anchovies (Engraulis capensis) and sardines (Sardinops sagax) (2). Adapted for their aquatic lifestyle, African penguins can reach speeds of 20 kilometres per hour in the water and range from 30 to 70 kilometres in a single trip; average dives last for 2.5 minutes, reaching depths of 60 metres. Penguins have waterproof coats that need to be constantly maintained by preening, when a waxy substance is distributed from the base of the tail. Even with these measures, their plumage is replaced yearly and African penguins come ashore to moult over 20 days between November and January in South Africa and between April and May in Namibia (5).

Threats

The population of African penguins has declined and it is estimated that its current size is a mere 10 percent of what it was at the turn of the 20th Century. Originally the fall in numbers was the result of the over-collection of eggs for food, and disturbance caused by the collection of guano for fertiliser. Today, however, depleted fish stocks due to over-fishing, and the risk of oil pollution are the most pertinent threats to the survival of this species (5); a recent oil spill affected around 40 percent of the population. Predation by Cape fur seals (Arctocephalus pusillus) and competition with them for food and breeding sites, as well as shark predation, has also had severe effects on population numbers (2).

Conservation

The African penguin is protected by its listing on Appendix II of the Convention on International Trade in Endangered Species (CITES) (3), and on Appendix II of the Convention on Migratory Species (CMS) (4). All of the breeding areas in South Africa are protected as National Parks or Nature Reserves and the collection of guano or eggs is no longer permitted. The recovery of rescued oiled birds has also been shown to be successful. Populations need further monitoring and the possibility of conserving fish stocks is under investigation, amongst other measures, if the future of Africa's only penguin is to be secured (2).

For further information on the African penguin see:

* BirdLife International:
www.birdlife.org
* International Penguin Conservation:
www.penguins.cl
* South African Foundation for the Conservation of Coastal Birds:
www.sanccob.co.za/index.htm

Authentication

Authenticated (01/06/05) by Samantha Petersen, Seabird Conservation Programme Manager, BirdLife South Africa.
http://www.birdlife.org.za/index.cfm

References

1. IUCN Red List (September, 2007)
http://www.iucnredlist.org
2. BirdLife International (April, 2003)
http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=3861&m=0
3. CITES (April, 2003)
http://www.cites.org
4. Global Register of Migratory Species (March, 2008)
http://www.groms.de
5. International Penguin Conservation (April, 2003)
http://www.penguins.cl
6. Animal Diversity Web (April, 2003)
http://animaldiversity.ummz.umich.edu/accounts/spheniscus/s._demersus$narrative.html
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From the IFAW Web Site

Classification:

Scientific Name: Spheniscus demersus
Class: Aves
Order: Sphenisciformes
Family: Spheniscidae
Genus: Spheniscus
Species: demersus


Distribution Map

Physical Description

The African, or jackass, penguin is a medium-sized penguin which stands about 45 centimeters (18 inches) tall and has a total body length of about 60 centimeters (24 inches). Males weigh an average of 3.6 kilograms (8 pounds) and females an average of 3.1 kilograms (7 pounds). However, they look extremely similar in the wild and small males may be smaller than large females.

Like all penguins, African penguins have a short, thick neck, a streamlined body and a short, wedge-shaped tail with small flipper-like wings. They are black on the back and wings, with a black band across the chest, and black cheeks. The bill is black with a light band around it. They have a white belly with black spots or speckles, black webbed feet and black claws. This fast-swimming penguin gets its nickname of "jackass" from the donkey-like call of territorial males.

Natural History

African penguins are endemic to South Africa and Namibia. They are distributed from Transkei to northern Namibia and breed in densely packed groups (colonies or rookeries) from Bird Island, Algoa Bay, to Hollams Bird Island, Namibia.

African penguins return to the same nest site and, usually, to the same partner each year. Because they are ground nesters, they require predator-free breeding areas and are therefore limited by the availability of predator-free islands and mainland areas. They nest in burrows in the sand, under overhanging rocks and bushes, or in the open. They used to nest in guano (bird droppings), but most of the guano was removed for fertilizer in the 19th century, causing destruction of most of this breeding habitat.

The breeding season usually starts in January on the islands and each pair usually lays two eggs, three or four days apart. Eggs are incubated by both parents for 38 days each. One parent guards the nest while the other feeds on anchovy, pilchard, horse mackerel and round herring. Chicks are born with gray down and are fed regurgitated food. Usually only the first chick survives, as there is insufficient food for two. The surviving chick fledges between 80 and 130 days depending on foraging conditions and proficiency of parents in providing food.

African penguins molt each year at their breeding island. As the insulating qualities of their feathers break down, they are no longer able to keep warm, and their feathers must be replaced. For the 21-day molt, the penguins are land-bound, unable to swim or feed. To prepare for it, they feed extensively for about five weeks before the molt begins.

The population of African penguins has crashed from at least 1.2 million in 1930 to 100,000 in 1978. The species is continuing to decline.

Status

Local conservation measures include permit-access-only to breeding islands, control of feral cats, and the restriction of fur seals onto penguin breeding areas.

Cleaning and rehabilitation of oiled birds is carried out by the private South African National Foundation for the Conservation of Coastal Birds (SANCCOB).

The African jackass penguin is listed as Vulnerable by the International Union for the Conservation of Nature and Natural Resources (IUCN). The drastic decline in their numbers is expected to continue and may result in the extinction of this species in 70 years. The African penguin is also listed on Appendix II by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

Threats to the Species

Historically, harvesting of eggs for human consumption was a major threat. Although a limited amount of egg collecting continues, the commercial harvest of eggs stopped in 1967 and is illegal today. Today, oil pollution from tankers cleaning their bilges and from oil spills are major threats. African penguins are also threatened by destruction of breeding habitat, competition for breeding space with other animals (e.g. fur seals), disturbance of breeding animals on the mainland by humans, vulnerability to predators such as leopards and dogs, and reduced prey availability due to commercial fishing. Some penguins are still killed and used as bait in certain fisheries.

International Trade

No legal trade.

Sources

CITES. 2001. African penguin. http://www.cites.org.

Enchanted Learning.com. 2001. Jackass penguin. http://www.zoomschool.com.

IUCN. 2001. The 2000 IUCN Red List of Threatened Species—Spheniscus demersus. http://www.redlist.org.

Payne, A.I.L. and R.J.M. Crawford. 1989. Oceans of life off southern Africa. Claeberg Publishers, Cape Town. 380pp.

UWC Enviro Facts. 2001. Jackass penguin. http://www.botany.uwc.ac.za.

First article and pics courtesy of ARKive @
http://www.arkive.org/african-penguin/spheniscus-demersus/info.html

Want to help? Go here, to the second source for the article and map:
http://www.ifaw.org/ifaw_southern_africa/save_animals/other/african_penguin.php

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