Red-hood gardener
| Red-hood gardener | ||||||||||||
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Red-hood gardener, portrayed by Richard Bowdler Sharpe |
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| Amblyornis subalaris | ||||||||||||
| Sharpe , 1884 |
The red- crested gardener ( Amblyornis subalaris ), also known as the red- crested bowerbird , is a species from the family of the bowerbirds (Ptilonorhynchidae) and is a representative of the avifauna of New Guinea. Compared to the Chlamydera species found in Australia or the silky arboreal bird , this species, belonging to the genus Amblyornis, has been relatively little researched due to its poorly accessible distribution area.
With a body length of up to 24 centimeters, the red-crested gardener is one of the smaller representatives in the bowerbird family and is roughly the size of a small thrush. He is one of the species whose courtship behavior includes the construction of an arbor by the male. No subspecies are distinguished for this species.
Red-crested gardeners are very long-lived and take several years to reach sexual maturity. Due to the intelligence they show when building their arbors, they are counted among the most intelligent of the birds. According to the IUCN, their stock situation is classified as safe ( least concern ).
features
Appearance
The red-hood gardener reaches a body length of up to 24 centimeters, of which 8 to 9.4 centimeters are on the tail. The beak length is 2.35 to 2.98 centimeters. You reach a body weight between 95 and 122 grams.
In the male, the face and top of the body are cinnamon brown with no further color markings. The reins and the feathers on the side of the feather bonnet are a little darker and more reddish. The feathers are elongated and orange-red in color at the back of the vertex. The tips of this bonnet are a little reddish to dark brown.
The bottom of the body is paler than the top of the body, the center of the chin, throat and front chest are almost reddish olive-brown. The thighs and the under tail-coverts are dark brown. The tail plumage is olive brown with white feather shafts. The iris is dark brown, the beak blackish with a lighter beak tip.
The female resembles the male, usually lacking the orange-red feathers. Older females can have one or more elongated feathers on the rear female. These are either orange-red as in the adult male or correspond to the cinnamon brown on the upper side of the body.
It is not yet clear at what age subadult males have an elongated bonnet.
voice
Clifford and Dawn Frith compare the vocal repertoire of the red hood gardener with that of the gold hood gardener, but point out that more detailed studies are still pending.
Distribution area and subspecies
The red-hood gardener occurs only on the southeastern peninsula of New Guinea. The distribution area extends from the northwest of Port Moresby over the Milne Bay to Mount Suckling .
The habitat of the red-crested gardener are mountain forests at low altitudes. Its height distribution ranges from 670 to 1200 meters, it is very rarely observed at heights of 1500 meters. In higher regions he is replaced by the golden hood gardener, the distribution areas of the two species rarely overlap.
The red-crested gardener only occurs in primary forests. The forests in which he lives are dominated by trees of the genera Lithocarpus and pseudo-chestnut . It is quite common in its area of distribution, but it is rarely noticed.
Food and subsistence
There are no studies on the feeding behavior of the red-crested gardener so far. However, it is very likely that it feeds on fruits and insects like the other species of the genus Amblyornis .
Reproduction
The males of the red-crested gardener are believed to be polygyn , that is, they mate with several females. The female builds the nest on her own, incubates the nest on her own and raises the young birds on her own. The males woo the females by building arbors, which, like the column gardener and the other Amblyornis species, belong to the "maypole" type. Compared to the gold cap gardener and the yellow crown gardener , the arbor of the red cap gardener, together with the hut gardener, is one of the comparatively more complex constructions, since like this he erects a maypole that is vaulted by a hut-like construction.
Clifford and Dawn Frith consider it possible that the red-hood gardener was displaced to lower altitudes by the more common gold-hood gardener - who is slightly larger with a body length of up to 26 centimeters. From their point of view, the more complexly built arbor may also be the result of a stronger separation of the two species from one another.
arbor
The arbors of the red crested gardener are typically located on slopes not far from the respective ridge. They are usually built in the shade of a tree. The distance between the individual arbors is comparatively small. It is 50 to 200 meters, with the average distance to the next arbor between 50 and 75 meters.
The individual arbors consist of a central maypole that is erected along a tree sprout with a height of up to five meters. The maypole consists of small branches and fronds of fern. Above it is a hut-like structure of twigs. The entire construction is between 60 and 80 centimeters high and between 90 and 120 centimeters wide. The hut-like structure opens up to a small platform at the front, to the left and right of which there is a tunnel-like entrance to the hut, each 10 to 12 centimeters wide. The red-crested gardener decorates his arbor like numerous bowerbirds. He uses numerous blue, purple, mauve, red, yellow and cream-colored fruits, flowers and leaves. These are usually placed on the maypole. Larger fruits, flowers, leaves as well as the wing of beetles, pieces of tree resin and mushrooms are deposited in front of the hut and also on the roof of the hut. The individual jewelry objects are often sorted according to their color.
Studies have shown that the males are more often visited by females if the arbors are carefully decorated and have a larger number of blue ornaments. Blue fruits or flowers are comparatively rare in the habitat of the red-crested gardener. The size of the arbors, on the other hand, has no influence on how often females come to the arbor.
Courtship time
The males stay at their arbors from September to December. In September the arbors are usually very well cared for, towards the end of December the male sets up further work and repairs on the arbor.
During the courtship season, the males spend about half of the day in arcades. A destruction of the arbor by competing males or a theft of jewelry objects by them has not yet been observed. However, this behavior is typical of many bowerbirds, and Clifford and Dawn Frith suggest that the cameras that were placed may have affected the behavior of competing males.
Courtship
If a female is found near the arbor, the male, who calls out, goes to the hut. As soon as the female first lands on the front canopy and then on the platform, the male's calls change. They become quieter and the calls inoculate gurgling sounds and metallic clicks. The male then approaches the arbor entrance very quickly and with a raised bonnet, making a sharp pop sound, which is followed by gurgling sounds. If the female has remained on the platform, mating occurs. The actual mating act takes only 3 seconds, the courtship for the female at least 189 seconds.
Nest and brood
The red-crested gardener's nests with hatched eggs have so far been found in December and January. The nest is cup-shaped and made of twigs and dead leaves. All of the nests investigated so far contained only one egg each. The fresh full weight is 19.7 grams, which corresponds to about 18.1 percent of the average body weight of a female.
So far, nothing is known about the rearing of the nestlings and their development.
Red-hood gardeners and people
William Ingram presented two red-crested gardeners to the London Zoo in 1908 and another bird of this species was given to the zoo in 1909. The latter survived 7 years in captivity.
The Koari people who live in the south of the Owen Stanley Mountains use the male's hood feathers as jewelry.
literature
- John Alcock: Animal behavior , from the American. by Matthias Sauerland, Gustav Fischer Verlag, 1996, ISBN 3-437-20531-5 , pp. 295 and 322
- Bruce M. Beehler, Thane K. Pratt: Birds of New Guinea; Distribution, Taxonomy, and Systematics . Princeton University Press, Princeton 2016, ISBN 978-0-691-16424-3 .
- Bruce M. Beehler: Birds of New Guinea , 1986
- Jared Diamond : The third chimpanzee . S. Fischer Verlag, Frankfurt am Main 1994, ISBN 3-596-17215-2 .
- Clifford B. Frith, Dawn. W. Frith: The Bowerbirds - Ptilonorhynchidae . Oxford University Press, Oxford 2004, ISBN 0-19-854844-3 .
- Mike Hansell: Bird nests and construction behavior , illustrated by Raith Overhill, Cambridge University Press, ISBN 0521017645 .
- Peter Rowland: Bowerbirds . Csiro Publishing, Collingwood 2008, ISBN 978-0-643-09420-8 .
Web links
- Video: Heinz Sielmann: Amblyornis subalaris - decorating the arbor . Institute for Scientific Film (IWF) 1967, made available by the Technical Information Library (TIB), doi : 10.3203 / IWF / E-1084 .
Individual evidence
- ↑ a b c streaked-bowerbird-amblyornis-subalaris Handbook of the Birds of the World zum Rothaubengärtnerl , accessed on April 17, 2017
- ↑ a b c d e f g Frith: The Bowerbirds - Ptilonorhynchidae . P. 288.
- ^ A b c Beehler & Pratt: Birds of New Guinea . P. 277.
- ↑ a b c d e Frith: The Bowerbirds - Ptilonorhynchidae . P. 287.
- ↑ a b c Frith: The Bowerbirds - Ptilonorhynchidae . P. 286.
- ↑ Frith: The Bowerbirds - Ptilonorhynchidae . P. 277.
- ↑ a b c d e f Frith: The Bowerbirds - Ptilonorhynchidae . P. 289.