Wednesday, February 4, 2009

Southern rockhopper penguin (Eudyptes chrysocome)




Southern rockhopper penguin (Eudyptes chrysocome)

Facts:

Kingdom Animalia
Phylum Chordata
Class Aves
Order Sphenisciformes
Family Spheniscidae
Genus Eudyptes (1)
Size Length: 52 cm (2)
Weight 3 kg (2)

Status

Classified as Vulnerable (VU) on the IUCN Red List (1).

Description

Previously classed as a single species, the rockhopper penguin has now been split into a northern (Eudyptes moseleyi) and southern species (Eudyptes chrysocome) (3). Although both species are similar in appearance, the distinctive yellowish plumes extending from the yellow line above the eye are significantly shorter and less dense in the southern rockhopper penguin (2) (3). The body is small but robust, with slate-grey upperparts and white underparts, the bill is short and reddish-brown and the eyes are red. Juveniles can be identified by the lack of adult yellow markings (2).

Range

The southern rockhopper penguin breeds on a number of Southern Ocean islands. Two subspecies are currently recognised, Eudyptes chrysocome chrysocome, which is found in the Falkland Islands, Isla Pinguino, Staten Island, and islands off southern Chile and Argentina, and Eudyptes chrysocome fiholi, which is found on several subantarctic islands to the south of New Zealand and South Africa (4).

Habitat

Nesting occurs on cliffs and rocky gullies, and chosen sites are usually situated near to freshwater, either natural springs or puddles (2).

Biology

A gregarious species, the southern rockhopper penguin breeds in large colonies that may comprise over a hundred thousand nests. Breeding pairs are monogamous, and usually return to the same nest every year. Egg-laying commences around November, with the female usually producing a clutch of two eggs of unequal size (2). Although, in general, only the chick from the larger egg survives to maturity, populations on the Falkland Islands frequently succeed in raising both (5). Incubation takes around 33 days, with both parent birds taking it in turns to sit on the eggs for extended periods of a time, whilst the other forages for food. Incubation is aided by a bare patch of skin on the lower abdomen (known as a 'brood pouch') that allows greater heat transfer to the egg. Once hatched, the male will remain to brood the chick for the first 25 days, whilst the female regularly brings food back to the nest. After this time, the chick is able to leave the nest, and will congregate with other chicks in small groups known as 'crèches' whilst the parent birds forage (2).

In order to maintain its waterproof coat, the southern rockhopper penguin engages in frequent grooming, which helps to flatten the feathers and to spread a waxy substance that is secreted just below the tail. Grooming is also an important social bond between pairs. After breeding the southern rockhopper penguin forages extensively in order to build up fat reserves in preparation for its annual moult. It takes around 25 days for the penguin's coat to be fully replaced, at which point it leaves the land and spends the winter months foraging at sea, before returning to shore to breed in the following spring (2). The diet of the southern rockhopper penguin is composed of a variety of oceanic species, such as crustaceans, squid, octopus and fish (4). Groups may often feed together and dives may be to depths of up to 100 metres (2).

Threats

Some southern rockhopper penguin nesting colonies have recently shown dramatic falls in numbers of breeding pairs. The Falkland Islands once housed the stronghold for southern rockhopper penguins, but over the last 60 years, numbers have declined by 90% (4). The reasons for these declines range from increasing disturbance and pollution, to declining fish stocks as a result of over fishing, failure to provide no-fishing zones around penguin colonies (6) and global warming (4).

Conservation

Many islands that house breeding colonies have been designated as reserves and the populations in the Falklands, Marion, Campbell Islands are regularly monitored and studied (4). Greater investigation of population demographics and of potential threats is required. Following the starvation of over 100,000 rockhopper penguins in the Falkland Islands, the Spheniscus Penguin Conservation Work Group published a report recommending that commercial fishing be excluded within 30 miles of penguin breeding sites (2). These measures have been adopted around southern Chile and Argentina, and these sites are healthy and increasing as a result. The adjacent Falklands have refused to introduce such protection, and populations continue to decline (6).

Further Information

To learn more about penguin conservation visit:

* International Penguin Conservation:
http://www.penguins.cl
* Falklands Conservation:
www.falklandsconservation.com
* Organisation for the Conservation of Penguins: English:
http://www.seabirds.org Spanish:
http://seabirds.org/chile.htm

References

1. IUCN Red List (January, 2009)
http://www.iucnredlist.org
2. International Penguin Conservation (January, 2009)
http://www.penguins.cl
3. Jouventin, P., Cuthbert, R.J. and Ottvall, R. (2006) Genetic isolation and divergence in sexual traits: evidence for the northern rockhopper penguin Eudyptes moseleyi being a sibling species. Molecular Ecology, 15: 3413 - 3423.
4. BirdLife International (January, 2009)
http://www.birdlife.org
5. Poisbleau, M., Demongin, L., Strange, I.J., Otley, H. and Quillfeldt, P. (2008) Aspects of the breeding biology of the southern rockhopper penguin Eudyptes c. chrysocome and new consideration on the intrinsic capacity of the A-egg. Polar Biology, 31: 925 - 932.
6. Bingham, M. (2002) The decline of Falkland Islands penguins in the presence of a commercial fishing industry. Revista Chilena de Historia Natural, 75: 805 - 818. Available at:
http://www.seabirds.org/resume.htm

All images and information courtesy of ARKive @

http://www.arkive.org/southern-rockhopper-penguin/eudyptes-chrysocome/image-G5895.html

See this page's links section for link to ARKive general.

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