Macaroni penguin (Eudyptes chrysolophus)
Facts
Kingdom Animalia
Phylum Chordata
Class Aves
Order Sphenisciformes
Family Spheniscidae
Genus Eudyptes (1)
Size Length: 71 cm (2)
Average weight: 5.5 kg (3)
Status
Classified as Vulnerable (VU A1b) on the IUCN Red List 2003 (1).
Description
This large, crested penguin is similar in appearance to other members of the genus Eudyptes; the macaroni penguin is, however, larger than all other species except the royal penguin (E. schlegeli) (4). Adult macaroni penguins have golden-yellow plume-like feathers that arise from a central patch on the forehead, extending back along the crown and drooping down behind the eye (4) (2). The head, chin, throat and upperparts are black; the underparts are white and the flippers are black on the uppersurface but mainly white below (4). The large bill is orange-brown; the eyes are red and there is a patch of bare pink skin from the base of the bill to the eye. The legs and feet are pink. Males and females are similar in appearance, but males tend to be slightly larger (4). Immature birds lack the head plumes or have a few sparse yellow feathers on the forehead; their bills are smaller than those of adults and are brownish-black in colour; the chin and throat are dark grey (4).
Range
The macaroni penguin has a circumpolar range (4). It breeds at 50 known sites on sub-Antarctic islands in the South Atlantic and southern Indian Oceans, with one breeding site on the Antarctic Peninsula (2) (4). Main breeding populations are located on the islands of Crozet, Heard, McDonald, Keruguelen and South Georgia (2). In 12 years, study populations on South Georgia have decreased by 65% and it is thought that the overall population on South Georgia has declined by 50% in the last 20 years (2). Most of the world population of this penguin has declined by at least 20% in the last 36 years (equivalent to three generations), but surveys are required to confirm the status of the species (2). The range of the macaroni penguin outside of the breeding season is unknown, although it is thought that it stays in Antarctic waters (4).
Habitat
Breeding colonies are situated on rocky slopes or level ground, usually in areas lacking vegetation, although some nests are located amongst tussock grass (4). Little is known of this species outside of the breeding season, but it is believed that it is pelagic, spending all of its time at sea (4).
Biology
The macaroni penguin is mainly active during the day. Very little is known of the species outside of the breeding season; most studies have been carried out on breeding birds. They feed mainly on krill (shrimp-like crustaceans), although in some areas, fish become an increasingly important food source as the breeding season progresses (5). It has been estimated that macaroni penguins alone consume four million tonnes of krill each year (6). In some populations, dives typically take the form of a V-shape, reaching depths of 48 m (4), although in other populations, the dive profiles were more complex (5).
Birds return to the breeding colonies each year in October and November, with males arriving before the females (4). Individuals often have to walk hundreds of meters over screes to reach their nest site (2). Macaroni penguins are monogamous and pair-bonds are long-lasting. Each year the pair reunites at the same nest location, recognising each other by means of their calls (4). Pairs often perform a display known as the ‘ecstatic display' in which their heads are swung from side to side (4). The nest is a simple scrape in the ground, typically lined with small rocks. In some cases, it may be made on a patch of grass and lined with grass shoots (4). Two eggs are laid; the second egg is always larger than the first and is usually the only successful egg per nest. If both eggs are lost, the pair is unable to produce a replacement brood (3).
Incubation takes up to 37 days and is shared by the parents in three main shifts. The first shift lasts for 8 - 12 days and is shared by the male and female. The second shift (12 - 14 days) is carried out by the female and the final shift (9 - 11 days) by the male. During each shift, the non-incubating bird goes to forage at sea during the day (4) (2). The newly hatched chicks are helpless, and for the first 23 - 25 days they are guarded and brooded by the male, while the female forages and feeds the chicks each day by regurgitating food (4). After this period, the chicks have developed their first plumage, which allows them to maintain their own temperature and so they can leave the nest. They cluster into small crèches for protection; at this stage, both parents are able to forage (3). Most chicks will have fledged at 60 - 70 days of age (4), at which point they have developed waterproof plumage (3). They do not start to breed until five years of age in females and six in males (4).
After the chicks leave the breeding colonies, the adults feed at sea for around three weeks before their annual moult. During the moult they are unable to forage, as their plumage is not watertight. After the 25-day moult the adults leave the colonies to spend the winter at sea (3).
In undisturbed colonies, predation is relatively low. Eggs (mainly deserted ones) are predated upon by skuas, sheathbills, and kelp gulls while weakened chicks, or those separated from the crèche are taken by skuas and giant petrels. Whilst at sea, adult macaroni penguins are predated upon by leopard seals and Antarctic fur seals (4).
Threats
Many penguin species of the Southern Oceans Ecosystem share a common set of factors that are causing population reductions (6) (2). Introduced predators such as cats and rats are a great problem for breeding birds on a number of islands, including South Georgia. Over-fishing is a very serious factor, in particular the harvesting of krill, the main food source of the macaroni penguin. Further pressures include oil spills and increasing tourism, as well as potential climate change, particularly as penguins are extremely sensitive to changes in sea temperature and ocean currents and the consequent decrease in prey availability (6).
Conservation
Although numbers of macaroni penguins are high, the decline of the overall population in the last 30 years have resulted in the classification of the species as globally Vulnerable by the IUCN Red List of Threatened Species (1). Long-term monitoring programmes are underway at a number of breeding colonies and many of the islands that support breeding populations of this penguin are protected reserves (2). The islands of Heard and McDonald are World Heritage Sites (2). If the suite of threats facing the macaroni penguin continue unabated, it seems likely that the population declines will continue.
Further Information
BirdLife International 2003 BirdLife's online World Bird Database: the site for bird conservation Version 2.0. Cambridge, UK: BirdLife International. (March 2004):
http://www.birdlife.org/
International Penguin Conservation Website (March 2004):
http://www.penguins.cl/macaroni-penguins.htm
Williams, T.D. (Ed.) (1995) Bird Families of the World – The Penguins. Oxford University Press, Oxford.
References
1. IUCN Red List of Threatened Species 2003 (March, 2004)
http://www.redlist.org
2. BirdLife International 2003 BirdLife's online World Bird Database: the site for bird conservation Version 2.0. Cambridge, UK: BirdLife International. (March, 2004)http://www.birdlife.org/
3. International Penguin Conservation Website (March, 2004)
http://www.penguins.cl/macaroni-penguins.htm
4. Williams, T.D. (1995) Bird Families of the World – The Penguins. Oxford University Press, Oxford.
5. Green, M.G., Williams, R. and Green, K. (1998) Foraging ecology and diving behaviour of macaroni penguins Eudyptes chrysolophus at Heard Island. Marine Ornithology, 26: 27 - 34.
6. Stokes, D.L. and Boersma, P.D. (1995) Conservation: threats to penguin populations. In: Williams, T.D. Ed. Bird Families of the World – The Penguins. Oxford University Press, Oxford.
Images and Information courtesy of ARKive @
http://www.arkive.org/macaroni-penguin/eudyptes-chrysolophus/info.html
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