Red-crowned bowerbird

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Red-crowned bowerbird
Systematics
Subclass : New-jawed birds (Neognathae)
Order : Passerines (Passeriformes)
Subordination : Songbirds (passeri)
Family : Bowerbirds (Ptilonorhynchidae)
Genre : Golden birds ( Sericulus )
Type : Red-crowned bowerbird
Scientific name
Sericulus bakeri
( Chapin , 1929)

The red-headed bowerbird ( Sericulus bakeri ) is a species from the family of bowerbirds (Ptilonorhynchidae). With a body length of about 27 centimeters, it is a relatively small bower bird. It occurs exclusively in the east of Papua New Guinea and is one of the species of this genus, whose courtship behavior includes the construction of an arbor by the male. As is typical for bowerbirds, there is a striking sexual dimorphism .

No subspecies are distinguished for the red-crowned bowerbird.

The IUCN classifies the population of the red-crowned bowerbird as potentially endangered ( near threatened ).

description

The males of the red-crowned bowerbird reach a body length of up to 26.5 centimeters, of which between 7.7 and 8.3 centimeters are on the tail. The females become slightly larger with a body length of up to 27 centimeters. With them fall between 8 and 9.1 centimeters on the tail plumage. The beak length is between 2.7 and 3 centimeters in the males and between 3 and 3.3 centimeters in the females. Males weigh between 178 and 183 grams, females weigh between 164 and 184 grams.

Appearance of the male

In the males, the vertex is orange-red with small black dots. The shiny orange-red neck feathers are strongly elongated like a mane. The rest of the body plumage is predominantly black, the face, throat, chest and wings have a bluish sheen in the light. The arm and hand wings are black with a chrome-yellow to orange-yellow base, so that the males have a conspicuous wing mirror even with folded wings . The tail plumage is black. The iris is white-gray, whitish to pale yellow. The beak is blue-gray with a black tip. The legs and feet are blackish.

Appearance of the females

The females are brownish olive on the top of the body. The head is a little paler, the ear covers and reins are a little lighter. Individual feathers on the upper side of the body have cream-white feather shafts, which makes the plumage appear slightly dashed, especially on the coat. The underside of the body has a dirty white base color. The chin and throat have narrow, brown-olive-colored transverse bands. On the rest of the underside of the body, this transverse ligament is slightly wider. The iris is dark brown. The beak is also dark brown. The legs and feet are brownish to lead gray.

distribution and habitat

Madang Province in Papua New Guinea, where the red-headed bowerbird is found

The red-headed bowerbird is endemic to the Adelbert Mountains of Papua New Guinea . The Adelbert Mountains are located in the Madang Province , a province in the northeast of Papua New Guinea, which with 29,000 square kilometers is about the size of North Rhine-Westphalia . The red-crowned bower bird occurs here in an area of ​​around 570 square kilometers in this mountain range, the highest peak of which is 1716 meters. The comparatively inaccessible mountains consist of rainforest and are characterized by their high biodiversity . There are around 700 species of birds, including 38 different species of birds of paradise .

The red-crowned bower bird typically inhabits altitudes between 1200 and 1450 meters in this mountain range, very rarely it is also found at altitudes of up to 900 meters. Wherever the red-crowned bowerbird finds suitable habitats, it is relatively common. Due to the small distribution area, the IUCN assumes fewer than 10,000 sexually mature individuals. The inaccessibility of the mountains helps protect the bird. The IUCN also sees no decreasing inventory trend.

Way of life

The red-crowned bowerbird is a shy bird that lives mainly in the middle to upper tree canopy. It can also be seen along the edges of the forest and occasionally visits the gardens of the indigenous peoples of this mountain region when garden trees bear fruit there. He lives solitary, in pairs or in small groups. In the troops there are typically several females for each male belonging to the troop.

As with bowerbirds, red-headed bowerbirds are polygamous . A male mates with several females and only the female takes care of the rearing of the young birds.

Arbor construction

Bower of yellow neck foliage bird . The red-headed bowerbird builds a similar arbor

As is typical for most bowerbirds, the male of the red-headed bowerbird also builds an arbor that serves as a courtship area. The American ornithologist Ernest Thomas Gilliard searched in vain for several weeks with numerous assistants towards the end of the 1960s for such an arbor, so that it was assumed for almost two decades that this type of arborebird was one of those that did not have this elaborate courtship behavior demonstrate. The first arbors were only discovered in September 1986.

The arbors of the red-crowned bowerbird correspond to those that are also found in other species of the genus Sericulus . They belong to the so-called "avenue type" with two parallel walls made of twigs. The built-in branches have a diameter of 1.5 to 8.2 millimeters. The longest built-in branches are 32 centimeters long. The branches built by the male typically have no branches and are slightly curved. The male builds the somewhat thicker branches on the outside of the avenue. The avenue is typically east-west facing. It is 20 centimeters long and 18 centimeters wide on the outside. The raised, middle corridor is 13 centimeters long and seven centimeters wide.

The red-crowned bowerbird seems to be one of those bowerbirds that decorate their arbor with colored objects. In the arbors found so far, these were exclusively blue objects. These include blue fruits of the genus Dianella with a diameter of one centimeter and blue-violet fruits of the genus Elaeocarpus , whereby this bowerbird species shows a preference for Dianella fruits. Arbors had between 8 and about 30 such blue objects, the majority of which were in the arcade. In the case of an active arbor, the arcade was also decorated with a yellow-brown leaf and four to five blue fruits were placed at the arbor entrance. A painting of the arbor has not yet been proven for this species. In a captive red-headed bowerbird, black-eared bowerbirds have been observed visiting the arbor and eating the blue fruits laid out.

How long a male of the red-headed bowerbird stays at his arbor or how he advertises for females has not yet been observed. The very attentive birds react to changes in the vicinity of the foliage and are also distracted by hidden observation posts.

Reproduction

So far, no active nests of this type have been found. Females ready for reproduction were observed or collected in August and February. A female was seen building a nest in September. The female used an epiphytic fern with tree fern- like leaves as a nest base , which was located on a branch 15 meters above the ground. This female built among other things lianas, twigs and mostly dry leaves.

nutrition

The red-crowned bowerbird feeds mainly on fruits and insects. He also looks for fruit-bearing trees in secondary forests and in the gardens of the indigenous population. Figs seem to play a special role in his diet.

Trivia

Rollo Howard Beck, who collected the type specimen of the red-headed bowerbird

The type specimen was collected in the 1920s by Rollo H. Beck (1870-1950), who led the Whitney South Seas Expedition on behalf of the American Museum of Natural History between 1920 and 1928 . The destination of this expedition was the South Pacific, during this expedition Beck visited over 600 islands and islets as well as over 1000 locations. When Beck returned to California in 1929, the Whitney South Seas Expedition had collected over 40,000 bird hides .

Beck kept the location of the red-crowned bowerbird secret, so that the type locality remained unknown for more than 30 years. In their monograph on the bowerbirds, Clifford and Dawn Frith suspect that this happened because Beck wanted to return to the collection area and find further, not yet scientifically described subspecies there. It was only after his death that the American ornithologist Ernest Thomas Gilliard received information about the site from Beck's widow.

The specific epithet honors George Fisher Baker (1878-1937), an American banker who was a member of the board of directors of the American Museum of Natural History. Baker's wife Edith was honored in a similar way: The endangered blue-fronted grouse , which was initially placed in its own genus, was given the scientific name Edithornis sylvestris . Today it is listed in the genus Pareudirastes .

literature

  • Clifford B. Frith, Dawn. W. Frith: The Bowerbirds - Ptilonorhynchidae . Oxford University Press, Oxford 2004, ISBN 0-19-854844-3 .

Web links

Single receipts

  1. ↑ Handbook of the Birds of the World on the Rotscheitel-Laubenvogel , accessed April 1, 2017
  2. ↑ a b c Sericulus bakeri in the IUCN Red List of Threatened Species 2016.10. Posted by: BirdLife International, 2016. Retrieved April 1, 2017.
  3. ↑ a b Frith: The Bowerbirds - Ptilonorhynchidae . P. 343.
  4. ↑ a b c d e Frith: The Bowerbirds - Ptilonorhynchidae . P. 344.
  5. ↑ a b c d Frith: The Bowerbirds - Ptilonorhynchidae . P. 345.
  6. ↑ Frith: The Bowerbirds - Ptilonorhynchidae . P. 121.
  7. ↑ a b Frith: The Bowerbirds - Ptilonorhynchidae . P. 346.
  8. ^ B. Beolens, M. Watkins: Whose Bird ?: Common Bird Names and the People They Commemorate , Christopher Helm, London, 2003