Pelt
| Pelt | ||||||||||
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Young bird of the scarlet |
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Phalacrocorax punctatus | ||||||||||
| ( Sparrman , 1786) |
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The punt ( Phalacrocorax punctatus ) is a bird from the family of cormorants (Phalacrocoracidae), which has an atypical, multi-colored plumage, in contrast to the other species in this family. The spotted shark, which only lives near the coast, can be seen on the coast of New Zealand .
The IUCN classifies the scar as not endangered ( least concern ).
Appearance
The potted scar reaches a body length between 64 and 74 centimeters. The wingspan is between 91 and 99 centimeters. Potted pods weigh between 700 grams and 1.2 kilograms. There is no noticeable sexual dimorphism . The orange-brown beak is long and slender. Legs and feet are orange.
In the magnificent dress, the back of the neck, back and rump are shiny greenish-black. The sides of the neck and the throat are black, while the side of the body is silver-gray and the wing covers light gray and the ends of the feathers are spotted black. A white, curved band runs from the eyes to the shoulder. The feathers of the forelock are white and are frizzy at the end. The featherless skin of the face is bright blue-green in the magnificent dress, the throat pouch is dark blue. In the plain dress the plumage is duller. The head of feathers has largely receded. The white band that stretches from the eyes to the shoulders in the magnificent dress is largely no longer visible. The featherless skin of the face is green.
Young birds are gray-brown on the upper side of the body, the feathers on the back of the wing-coverts have dark tips. The underside of the body is gray-white to cream-colored. The beak is reddish yellow. The featherless skin of the face is yellow like the eye ring. The iris is dark brown and the legs and feet are yellow.
Possible confusion
Due to its slender physique and greyish plumage, the pothole can only be confused with a few other species. The warthog and the steward's scar are both more powerfully built. Their thicker neck and their shorter wings are particularly striking. The similar-looking Pittscharbe does not occur in New Zealand waters.
Typical behaviors
The pothole usually stays two to 16 kilometers from the coastline in the open sea while foraging. Occasionally, however, they can also be seen while foraging in sea bays and estuaries. On land the gait is usually quite fast, they raise their legs relatively sharply when walking, the body is only slightly inclined forward. The flight is very fast, the head and neck are stretched far forward. Troops of spotted shags often fly in a long, slightly staggered line or in a V-shaped formation. In general, pelts are sociable birds that look for food, rest or breed in small flocks.
Habitat and existence
The potted shear is a seabird and occurs in the coastal waters of the two main New Zealand islands and in the waters around Stewart Island . The main area of distribution is the New Zealand South Island. The pelt usually looks for their food in waters that are at least ten meters deep. In general, whiteflies are birds that are faithful to their location, and the individual resting places will use them for several years. Occasionally, however, ringed birds are found up to 500 kilometers from the ringing location.
The population was estimated at 60,000 to 150,000 breeding pairs towards the end of the 20th century. Individual breeding colonies have been wiped out by hunting, but there are hundreds of breeding colonies along the New Zealand coast. In coastal regions that are heavily used by people, the population is generally declining somewhat.
Way of life
In general, very little is known about the way of life of the spot. It is believed that potted shags mainly feed on small crustaceans and possibly small fish. The duration of the individual dives observed just off the coast of New Zealand averaged 12 seconds; however, only 30 dives were observed. They look for food individually or in groups of up to 100 individuals.
The punt is a colony breeder, the breeding colonies comprise between 9 and 360 nests. They prefer to nest on rocky sections of the coast, the nests are built on ledges. They are rarely associated with other seabird species. The mestabstamd within the breeding colonies is about one meter. The nests are made of seaweed and have an outer diameter of 64 centimeters. The nest continues to be built during the breeding season, as soon as the nestlings have hatched, these activities are stopped. Since the young birds remove nesting material during their nestling period, the nests are usually no longer available when the young birds are two to three weeks old.
The clutch consists of one to four eggs. These are elliptical, have a rough surface and are freshly laid of a pale blue color. The laying interval is 48 hours. Both parent birds are involved in the brood. Newly hatched nestlings are naked and have their eyes closed. They weigh around 40 grams when they hatch, which is around three percent of the weight of an adult bird. The eyes do not open until they are around three days old. At two weeks of age, the body is covered with dunes, but the top of the head and the regions under the wings are still bare. At 34 to 38 days, they weigh more than the adult birds; when they fled, they are slightly heavier than the average adult bird.
The breeding success has so far only been investigated in a few colonies. In a breeding colony in Otago , the breeding success in 1984 was 54.4%: 185 young birds hatched from 256 laid eggs and 129 of them fledged. In the previous year, however, hardly any young birds grew up in this breeding colony. In general, more young birds grow in nests with only two eggs than in those with three eggs. Clutches that were laid in October had a higher success rate than those that were laid in September or November. The eggs are mainly eaten by the herring head gull . These get to the eggs when the pods leave their nests due to disturbances.
supporting documents
literature
- PJ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds , Volume 1, Ratites to Ducks, Oxford University Press, Oxford 1990, ISBN 0195530683
Web links
- Phalacrocorax punctatus in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 31 of 2009.
- Videos, photos and sound recordings of Phalacrocorax punctatus in the Internet Bird Collection