Crested penguin
| Crested penguin | ||||||||||||
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Crested penguin |
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| Eudyptes chrysolophus | ||||||||||||
| ( Brandt , 1837) |
The crested penguin ( Eudyptes chrysolophus ) is a species of penguin belonging to the crested penguin genus . It is the most common penguin species worldwide and is found on many sub-Antarctic islands and in the extreme south of South America. Despite the large population, the IUCN assesses the golden crested penguin as endangered ( vulnerable ) because the population has been falling sharply for at least three generations. No subspecies are distinguished.
The very similar crested penguin , which brooded almost exclusively on Macquarie Island , was long considered a subspecies of the golden crested penguin, but is now almost universally classified as an independent species.
description
Height, weight and age
With a size of up to 71 centimeters, the golden crested penguin is the largest representative of the crested penguin genus. There is no noticeable sexual dimorphism . Female golden crested penguins are only slightly smaller than males, which is particularly noticeable when breeding pairs can be observed. The weight of golden crested penguins varies considerably over the course of the year. In males it varies between 3.4 and 6.4 kilograms. Females range in weight from 3.2 to 5.7 kilograms. Crested penguins usually reach their maximum weight shortly before moulting . They are easiest after moulting. The average life expectancy is 12 years.
Adult crested penguins
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The head, chin and throat are bluish black. The showy and elongated golden yellow feathers grow on the forehead about an inch from the base of the beak. They are directed backwards and point down and up behind the eye. The top of the body and the tail are freshly molted bluish black. The plumage looks a little more brown shortly before moulting. The underside of the body is white and sharply set off from the black throat. The wings, which have been transformed into fins, are bluish black on the upper side with a thin white line on the fin side. The underside is white with a black spot at the end of the fin. The large and strong beak is dark orange-brown, in older birds the upper beak occasionally has vertical grooves. A conspicuous pink triangle of non-feathered skin runs from the base of the beak to the eye. The iris is reddish. Feet and legs vary from a flesh-colored shade to a rich pink. The soles are blackish.
Occasionally, white-faced and generally paler-drawn golden crested penguins are observed, which in their plumage are very similar to the crested penguin . It is not yet certain whether these are color morphs or even hybrids with the crested penguin. Occasionally the golden crested penguin breeds with the rockhopper penguin .
Fledglings
Fledglings can be distinguished from adult golden crested penguins up to an age of two years on the basis of plumage differences. Up to one year old they are noticeably smaller than the adult golden crested penguins. During this period they either show no or only a few golden yellow feathers on their foreheads. The beak is narrower, less strong and dull brown in color. Older young birds already have the elongated facial feathers typical of golden crested penguins, but the feathers are even smaller than in sexually mature birds. Three to four year old golden crested penguins that are not yet breeding can no longer be externally distinguished from sexually mature birds. They reach sexual maturity between the ages of five and six.
voice
The sound repertoire of the golden crested penguins is similar to that of other crested penguins. They are particularly fond of shouting in the breeding colonies at the time when the pairs find each other and they establish their immediate breeding area. During the time in which the clutches are incubated, however, relatively few calls can be heard in the breeding colonies. Only when the parent birds separate during the brood can more calls be heard.
Most calls consist of a loud and harsh bell and trumpet-like calls. The two birds in a pair as well as the chick belonging to them recognize each other by their voice, the exact nesting location plays no role or only a subordinate role in finding the partner bird or the chick. Local differences can be identified in the repertoire of calls. The vocalizations of the golden crested penguins that breed on South Georgia are faster in rhythm and slightly higher. Males call a little longer and generally have a slightly lower voice.
The call repertoire includes short, monosyllabic calls that are considered contact calls. Trumpet-like calls can be heard especially when the partners take turns incubating the clutch. The calls of the chicks cannot be distinguished by the parent birds until one week after hatching.
distribution
The golden crested penguin is almost circumpolar. Its breeding area includes sub-Antarctic islands of the Indian Ocean and the Atlantic Ocean between the 46th and 65th latitude. He usually stays north of the pack ice border. There is at least one breeding colony located on the Antarctic Peninsula . This makes it the crested penguin that breeds furthest south . The area in which the golden crested penguins stay outside of their breeding season is largely unknown. However, it is believed to be in Antarctic waters between 45th and 65th latitude south. Odd guests have been observed off the coasts of South Africa , Australia and New Zealand . There are no observations on land outside of the breeding season. It is therefore assumed that it lives pelagically outside of the breeding season .
Breeding colonies of the golden crested penguin can be found on numerous sub-Antarctic islands. The most important are Kerguelen , Crozet Archipelago , Heard and McDonald Islands , Prince Edward Islands and Bouvet Island , South Georgia , South Shetland Islands and South Orkney Islands , with the colonies on South Georgia being by far the largest. Nine small colonies can also be found on islands at the southern tip of South America. Brooding golden crested penguins are also occasionally reported from the Falkland Islands . There they occasionally mate with rockhopper penguins and for 1995 there are indications that a breeding bird was observed whose beak and facial plumage make it possible that it is a hybrid of such a mating.
Breeding colonies are found on steep, rocky slopes of the coast. Typically, there is a lack of vegetation where there are breeding colonies. However, there are also isolated colonies where crested penguins breed between tufts of grass.
nutrition
Crested penguins eat crustaceans ( e.g. Euphausia , Thysanoessa , Munida gregaria , Themisto gaudichaudii ), squids ( Gonatus antarcticus , Loligo gahi ) and fish ( Notothenia , Champsocephalus gunneri ). Fish and cephalopods play a bigger role, especially towards the end of the rearing of young birds. While searching for food, golden crested penguins undertake dives to a maximum depth of 115 meters. However, they usually find their food in water depths between 15 and 50 meters. The search for food takes place mainly during the day. Crested penguins usually spend between 11 and 12 hours foraging. During the breeding season, however, they can be in search of food for between 25 and 50 hours, and towards the end of the offspring they also increasingly look for food at night. During the breeding season and shortly before moulting, golden crested penguins are also absent for ten to twenty days to look for food.
Crested penguins usually leave the breeding colony in the early hours of the morning between 5:00 and 7:00 a.m. and return around 6:00 p.m. They usually find their food in the region of continental shelves . In South Georgia these feeding grounds are about 50 kilometers from the breeding colonies. Crested penguins spend an average of 38 percent of their foraging in finding these food grounds. You swim at a speed of around 2.08 meters per second. During their dives, they spend an average of 1.48 minutes underwater. They spend 48 percent of their time in search of food underwater. All dives are V-shaped, which means that the golden crested penguin does not spend a long time in the deepest water layer, but immediately reappears after reaching the maximum depth.
Reproduction
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Females breed from the age of five, males only rarely before the age of six. You are very loyal to your location and your partner.
The breeding season begins in mid-October. Rocky coasts and low cliffs serve as breeding grounds, the nest density is 0.7 to 1.4 nests per square meter. Two eggs are laid every four to five days, the first weighing around 93 grams, the second around 150 grams. The second egg is behind the first, where the temperature is most stable and the egg is less likely to be lost or stolen. The smaller first egg requires a longer incubation period and is rarely successfully incubated.
The breeding season lasts around five weeks and is divided into three phases of equal length. In the first phase both parents are at the nest, in the second only the female breeds, in the third only the male; the other partner goes hunting. The female sometimes only returns a week after the chicks hatch, as long as the chicks may have to wait for their first meal.
After hatching hudert the male chicks for another 24 days while the female goes hunting. The chicks are fed daily after their first meal, newly hatched chicks need around 200 grams a day.
At the end of the 24 days, the chicks have developed their second downy coat, leave the nests and form groups with other chicks that allow both parents to leave the nest and go hunting in order to meet the chick's growing need for food (per feeding to this time around 1000 grams). At the age of 11 weeks the animals develop a waterproof plumage and become independent.
Three weeks after the chicks have become independent, the adult birds begin moulting , which lasts around 25 days. Then the birds leave the breeding grounds and spend the winter months in the sea.
Enemies
Adult animals have no natural enemies on land, but in the sea they are prey to orcas , leopard seals , maned seals and fur seals . Eggs and chicks are eaten by skuas , seagulls and birds of prey .
Duration
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The IUCN estimates the population of the golden crested penguin at 18 million sexually mature individuals. Overall, however, one can speak of at least 24 million individuals. The largest populations are found on the islands of Ile des Pingouins of the Crozet Islands, on Heard and McDonald with about one million breeding pairs each, the Kerguelen with 1.8 million breeding pairs and South Georgia with 2.5 million breeding pairs. The populations on South Georgia and Bouvet probably increased significantly in the 1960s and 1970s, but have declined again since then. Well-studied individual populations on South Georgia decreased 65 percent between 1986 and 1998. Overall, it is assumed that the breeding bird population on South Georgia has halved in the last twenty years. The same applies to the examined populations on Marion, which halved between 1979 and 1998. The situation is different on the Kerguelen, where the population increased by one percent annually between 1962 and 1985. Data since 1998 indicate that the breeding colonies there are at least stable in terms of population size, or possibly even increasing slightly. For the numerically not very significant populations whose breeding colonies are on South American soil, there are only few data, but these indicate a stable population.
The main population influencing factors are those that affect all species in the southern oceans. They are negatively affected by commercial fishing, ocean warming and increasing oil pollution.
supporting documents
literature
- Mike Bingham: Penguins of the Falkland Islands & South America. Pp. 48-51, 2001, ISBN 0-7596-3335-5 .
- Tony D. Williams: The Penguins. Oxford University Press, Oxford 1995, ISBN 0-19-854667-X .
Web links
- Eudyptes chrysolophus in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 2 of 2009.
- Videos, photos and sound recordings of Eudyptes chrysolophus in the Internet Bird Collection
Single receipts
- ↑ BirdLife factsheet on the golden crested penguin , accessed on November 21, 2010
- ^ Williams, p. 213
- ↑ a b c d Daniel Gilpin: Penguins . Parragon, ISBN 978-1-4075-0629-6 .
- ^ Williams, p. 211
- ^ Williams, p. 212
- ^ Williams, p. 213
- ^ Williams, p. 214.
- ^ Williams, p. 214.
- ^ Williams, p. 215.
- ^ Williams, p. 215
- ^ Robin and Anne Woods: Atlas of Breeding Birds of the Falkland Islands , Anthony Nelson, Shorpshire 1997, ISBN 0-904614-60-3 , p. 35
- ^ Williams, p. 215
- ^ Williams, p. 215
- ↑ BirdLife factsheet on the golden crested penguin , accessed on November 21, 2010
- ↑ BirdLife factsheet on the golden crested penguin , accessed on November 21, 2010