Crowned penguin
| Crowned penguin | ||||||||||
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Crowned penguin |
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Eudyptes sclateri | ||||||||||
| Buller , 1888 |
The crown penguin ( Eudyptes sclateri , Syn. : E. atratus ), also Sclater penguin called or yellow Macaroni Penguin is a penguin -Art that on to New Zealand belonging Bounty Islands and Antipodes Islands breeds. It belongs to the genus of the crested penguins .
The abundance of the species is, according to the IUCN endangered ( endangered ). The reason for the classification is a sharp decline in the population over the past 45 years, which is still ongoing. Crested penguins also have a small distribution area and only breed on two islands. Extraordinary events can therefore have a very strong impact on the population.
Appearance
The crowned penguin can reach a body length of up to 67 centimeters. Males tend to be slightly larger and heavier than females, weighing between 4.4 and 6.4 kilograms. In females, the weight range is 2.9 to 5.6 kilograms. Compared to other crested penguins, only relatively little data is available on the seasonal weight ranges of crested penguins. For example, there is a lack of data on the weight of the males after moulting . So far, this has only been determined for females and represents the seasonal minimum weight, which probably also applies to males. Females and males reach their maximum weight just before the start of moulting. The difference in weight and height between the sexes is the only noticeable sexual dimorphism . It is particularly noticeable when a breeding pair can be observed.
The freshly moulted plumage of the adult crowned penguins is velvety black on the back, the wings and the head. Immediately before moulting, the worn and faded plumage appears brownish, as is the case with many penguin species. The underside of the body is whitish and sharply set off against the black throat. The wings, which are shaped into fins, are blue-black on the upper side and whitish on the underside with a large black spot at the end of the fin. The crowned penguin is characterized by two pale yellow feather heads that point backwards from the nostrils over the dark red eyes along the top of the head. The feathers that form these feather heads can reach a length of up to six centimeters.
The long and relatively slender beak is brownish-orange. It is set off from the head plumage by a bluish-white skin, which forms a conspicuous triangle at the base of the beak, similar to that of the snare island penguin . The iris is brown. The legs and feet are pink on the front. The back of the legs, the soles and the front ends of the webbed feet, on the other hand, are brown-black.
Crowned penguins that have just fledged and one year old are smaller than the adult birds. They also have paler and shorter feather heads. The chin is greyish white to gray, the featherless skin at the base of the beak is less noticeable than in adult birds, the beak is slimmer and has a pale tip in some individuals. Two-year-old crown penguins can also be distinguished from adult penguins by their even shorter feather tails.
Due to the conspicuous feather heads, there is little possibility of confusion with other penguin species in the crested penguins observed on land. At sea, when the wet feather heads rest against the sides of the neck, the crested penguin is very similar to other crested penguins. It is most similar to the snare island penguin. However, this species has a stronger beak.
Food and predators
The primary diet of penguins is made up of fish, small cephalopods and krill . The predators are sharks , killer whales , New Zealand fur seals and New Zealand sea lions.
distribution
The habitat of the Crested Penguins are the cool sea waters in the region of New Zealand. Crested penguin breeding colonies can only be found on the Antipode Islands and the Bounty Islands, and in the 1980s in small numbers on the Auckland Islands . They can be observed in their breeding area from September to April. The area in which crown penguins stay outside of the breeding season, however, is largely unknown. In the winter half of the southern hemisphere, however, crown penguins were observed both in the Cook Strait and on the east coast of New Zealand's South Island . Odd guests occasionally reach the south coast of Australia, the Macquarie Island and the Chatham Island . In the 1960s, an individual was seen even off the Falkland Islands .
Originally, a breeding colony was also on Campbell Island , where a few hundred birds were breeding in the 1940s. In 1986/1987 around twenty pairs of crowned penguins were observed here, but they did not breed. At the beginning of the 1980s, cattle and sheep farming were discontinued on Campbell Island and the brown rat that was introduced there was exterminated. So far, however, the island does not appear to be used as a breeding colony by crowned penguins.
Reproduction
The reproductive behavior of crowned penguins has so far only been insufficiently investigated. Basically, however, it is assumed that it is largely similar to that of other crested penguins. Particular similarity is assumed with the behavior of the thick-billed penguin and the snare island penguin . However, the few studies that have been done to date indicate that crowned penguins exhibit less aggressive behavior than these two species. The aggressive behavior of the Crowned Penguins includes stretching the head forward, during which they make a low growl or a sharp barking noise. The beak is opened and the head tilted slightly to one side. In direct disputes, they grab each other by the beaks or bite their opponent in the neck while they beat him with their fins.
Crested penguins use rocky stretches of coast as the location of their breeding colonies. Usually there is no vegetation, the ground is not covered by soil and the breeding colonies are no more than seventy meters above sea level. They return to these breeding colonies at the beginning of September. Individual breeding colonies are found in the vicinity of breeding colonies of the rockhopper penguin and the white-capped albatross . The nests are in great density to each other and are usually 66 centimeters apart. Breeding colonies usually contain more than 1,000 pairs. The actual nest is a shallow, simple hollow on the ground and is located between larger boulders. Occasionally the edge of the nesting trough is made of small stones and sometimes there is grass brought in by the penguins in the nesting trough.
The laying of eggs on the Antipodal Islands occurs in the first half of October; on the Bounty Islands, breeding begins about three weeks earlier. The clutch consists of two eggs. These are obtuse oval and have a pale bluish or greenish skin color. The incubation period is 35 days. Most clutches only hatch one chick. 97 percent of couples who lost an egg were the first to lay eggs. In 46 percent of the cases, the egg was removed from the breeding birds themselves. The predators that eat eggs and chicks are mainly skuas . On the few clutches where both chicks hatch, there is an obligatory breeding reduction because the parent birds cannot get enough food to raise both chicks. Usually it is the chick of the second egg that is raised.
Little is known about the development of the young bird. Older fledglings live in groups and are fed by both parent birds. Usually it is the female who brings in food more often. Young birds just before they fled, weigh an average of 3.6 kilograms. In the Antipodal Islands, most of the young birds leave the breeding colony around January 30th. From February 12th, there will be no more young birds in the breeding colonies located there.
Duration
The total stock of black penguins is estimated at 150,000 to 170,000 sexually mature individuals. At the end of the 20th century, 28,000 breeding pairs were still breeding on the Bounty Islands. On the Antipodal Islands, however, there are around 49,000 to 57,000 breeding pairs.
The breeding population on the Bounty Islands decreased by around 76 percent between 1978 and 1998, while the breeding bird population on the Antipodal Islands halved in the same period.
supporting documents
literature
- Tony D. Williams: The Penguins . Oxford University Press, Oxford 1995, ISBN 0-19-854667-X
Web links
- Eudyptes sclateri in the Red List of Threatened Species of the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 2 of 2009.
Single receipts
- ↑ BirdLife Factsheet on the Crowned Penguin , accessed on November 20, 2010
- ^ Williams, p. 207
- ^ Williams, p. 206 and p. 207
- ^ Williams, p. 206
- ^ Williams, p. 206
- ^ Williams, p. 207
- ^ A b Daniel Gilpin: Penguins . Parragon Books Ltd., 2007, ISBN 978-1-4075-0629-6 .
- ^ Williams, p. 207
- ↑ BirdLife Factsheet on the Crowned Penguin , accessed on November 20, 2010
- ^ Williams, p. 209
- ^ Williams, p. 211
- ^ Williams, p. 211
- ↑ BirdLife Factsheet on the Crowned Penguin , accessed on November 20, 2010