African penguin (Spheniscus demersus)

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).

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

All info from ARKive @

http://www.arkive.org/african-penguin/spheniscus-demersus/info.html