Drop arbor bird
| Drop arbor bird | ||||||||||||
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Drop arbor bird |
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| Chlamydera guttata | ||||||||||||
| Gould , 1862 |
The drop Laubenvogel ( Chlamydera guttata ) is a kind from the family of Bowerbirds (Ptilonorhynchidae) and is a member of the avifauna of Australia . Compared to the three-gang bowerbird , which only occurs in New Guinea , this species has been relatively well researched due to its distribution in Australia.
With a body length of up to 28 centimeters, the drip arborvird is one of the smaller representatives in the bowerbird family and is one of the species whose courtship behavior includes the construction of an arbor by the male. In its appearance it is reminiscent of the spotted arboreal bird found in eastern Australia . In contrast to many bower birds, there is no noticeable sexual dimorphism . No subspecies are distinguished for this species.
Drop arborebirds 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
Body measurements
Drop arborebirds reach a body length of up to 28 centimeters, of which 8.6 to 10.6 centimeters are accounted for by the tail in the nominate form . The beak length is 2.8 to 3.1 centimeters. The males reach a weight between 128 and 142 grams, females are almost the same weight with 122 to 148 grams.
Appearance of the males
The plumage of the drop arborebird is individually very variable in its basic color and the color markings, which means that the plumage wears off quickly.
The parting is dark gray-brown with blackish feather edges, most feathers have fine, small, silvery shimmering feathers. On the nape of the neck it has an elongated purple-colored spot consisting of somewhat elongated feathers that can be raised on top. The rest of the top of the body is black-brown to blackish. The individual feathers have silvery white, ocher, chestnut or isabel-colored feather tips, so that the bird looks spotted on the upper side of the body. Especially in birds that are about to moult, these spots may have almost completely disappeared due to the wear and tear of the plumage.
The chin, throat, ear covers and front chest are black-brown with very small light brown to dirty white feathers. The rest of the underside of the body is isabel-colored, with the chest being slightly darker than the rest of the underside of the body. The under tail-coverts are pale clay-colored with a darker cross-banding. The bill is blackish to black, the iris is dark brown.
Appearance of females and fledglings
The female resembles the male, but with them the neck mark only forms with increasing age. The tail plumage tends to be a little longer and the throat tends to be a little more spotted.
Like the females, juveniles have a slightly longer tail plumage than the adult males. The tips of the feathers are lighter so that the young birds appear lighter overall. The purple patch on the neck is still missing on them.
voice
The calls of the drop arborebird include clicking, rattling and hissing sounds as they are also described for the spotted and gray bower bird .
As described for many bowerbirds, the drop arboreal bird also imitates the calls of various bird species in its area of distribution as well as a wide range of ambient noises, especially the presence of predators can lead to the imitation of certain calls.
Among the counterfeit Call include the ring parakeet , yellow forehead chat bird , Pfeifhonigfressers ( Lichensostomus quadrangle ), Black Face crawler catcher , Black-throated crows Strangler ( Cracticus nigrogularis ), Bennett Crow , wedge-tailed Weihs , Brown-throated honeyeater ( Acanthagenys rufogularis ) Neuhollandkrähe , brown falcon , blue-winged kookaburra , Brauensäbler (Pomatostomus superciliosus) and zebra finches . The drop arborebird also mimics the coughing of people, the neighing of horses, the barking of dogs and the meowing of cats.
Distribution area and habitat
The drip arborebird is, apart from the gray bowerbird , which occurs in tropical northern Australia , the only bowerbird with a distribution area in western Australia. Its range is disjoint . In Western Australia , its distribution area extends from the North West Cape on the Western Australian coast through the Pilbara area to the interior of this Australian state. A second distribution area extends in a long band along the border of the Northern Territory to a region 200 to 300 kilometers northeast of Alice Springs . The distribution area of the drip arborebird does not overlap with that of the outwardly similar blotch arborebird . The distribution areas of the two species have a gap of around 100 kilometers between 137 ° and 138 ° east.
There are two subspecies:
- C. g. carteri - Mathews, 1920 - North West Cape, in Western Australia.
- C. g. guttata - Gould, 1862 - Western Australia from Eighty Mile Beach southeast of the North West Cape, via Pilbara to the interior of Western Australia and from the Rawlinson Range to the Northern Territory.
As a habitat, the driftwood bird prefers forest areas along rivers. But it also occurs in ravines and in rocky regions if there is enough water there. Its distribution area strongly overlaps with that of the wild fig species Ficus platypoda . The association of the arborvitae with this shrub was already known at the beginning of the 20th century: The sometimes incomplete distribution of the arboreal bird and its southern limit of distribution were explained by the occurrence of this plant. However, Clifford and Dawn Frith point out that the drip arborvaire can also be found in regions where this plant is absent.
Basically, the drip arborebird occurs in much drier regions than the gray bower bird . It also settles in regions that have only 130 milliliters of precipitation annually.
Way of life and food
Due to the spotted plumage in the undergrowth, the drip arborebird can usually hardly be made out. Basically, it is a shy bird that only comes near people during dry seasons in search of water. Often several birds can be seen at the same time at water points.
Ficus platypoda bears fruit all year round. In the Everard Ranges near the Mintabie opal field , leaf-bowerbirds cover about half their food needs with these figs. They also eat the drupes of sandalwood trees ( Santalum spicatum ), snake- hair cucumbers and the closing fruits of belt flowers .
Their diet also includes nectar and flowers, especially from various trees of the Acacia genus, as well as spiders and insects such as moths, ants, beetles and grasshoppers. Smaller troops occasionally visit gardens to eat the vegetables and fruits that have been grown there.
Reproduction
The males of the drip arborebird are polygyn , that is, they mate with several females. The female builds the nest alone, incubates the clutch on her own and raises the young birds on her own. The males woo the females with the construction of arbors, which, like the silky-bowerbird , the sericulus species and the other species of the genus Chlamydera, belong to the "avenue" type. As with other species of bowerbird, this arbor is adorned with decorative objects and the walls of the arbor is partly painted. The male spends most of the year near his arbor. They mate especially in the period from August to December.
arbor
The male builds an arbor consisting of two parallel walls made of flexible branches. It usually stands on a platform made up of branches that are 15 to 20 centimeters high. Arbors are on average 36 inches long and 16 inches wide. The height, measured on the inside of the walls, is 23 centimeters. Unlike many other bowerbirds, the central aisle of the arbor is not oriented in a particular direction. As a rule, the male builds it under the overhanging second of a tree. They are often so well hidden that they are not even visible from a distance of two meters.
Of 12 arbors examined at the North West Cape , two were at the bottom of a ravine, four were at the crest of a hill, and six were in the flat coastal plain of this peninsula. The distance from one arbor to the other was between 1.2 and 2 kilometers. There is evidence that the males build a new arbor every two to three years. They often use the same location and erect the new arbor just a few meters away from the old one.
Decorating the arbor
To decorate the arbor, the males use berries, fruits, seed pods and man-made objects. The number of objects that will decorate a single arbor can be high. Similar to the Eastern Australian spotted arborvitae, the number of jewelry objects presented can be more than 1000.
In a more closely examined arbor near the Exmouth Gulf , the male used 136 mainly fresh mulga seed pods , 18 green berries of a thorn apple species , 12 pods of a Jasminum species, 4 seed pods of Acacia species and an unidentified seed pod as decoration . In addition, the male had collected 93 ammunition cases, 20 calcite crystals, several bleached bones and numerous whitish pebbles. In an arbor examined near Alice Springs , the male used 1,427 bone objects, 174 snail shells and numerous pebbles and grail and metal fragments. In total, the attached decoration material weighed 7.4 kilograms.
Occasionally the males also paint their arbor. One male used the flowers of an emus bush that he had chewed to a pulp.
Nest, brood and clutch
The breeding season falls between the months of July and March. The nest is built in low trees, in bushes or occasionally in climbing lianas. It consists of a loose platform made of dry branches on which a flat bowl nest sits, which is laid out with thinner branches, grass and casuarina needles. The clutch consists of two eggs, more rarely just one egg. The eggs are pale gray-green to isabel in color and have a dense pattern of brown to black-brown scribbles. The rearing of the nestlings has not yet been conclusively investigated.
Drop arborebirds and humans
Occasional drip arborebirds have been kept near Alice Springs and in West Australia. More detailed descriptions of the keeping were not available until 2004.
literature
- 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 .
- Clifford B. Frith, Dawn. W. Frith: The Bowerbirds - Ptilonorhynchidae . Oxford University Press, Oxford 2004, ISBN 0-19-854844-3 .
- Peter Rowland: Bowerbirds . Csiro Publishing, Collingwood 2008, ISBN 978-0-643-09420-8 .
Web links
Single receipts
- ↑ a b c Handbook of the Birds of the World on the Drop Arborvogell , accessed on April 10, 2017
- ↑ a b c d e Frith: The Bowerbirds - Ptilonorhynchidae . P. 419.
- ↑ a b c d Frith: The Bowerbirds - Ptilonorhynchidae . P. 416.
- ↑ Frith: The Bowerbirds - Ptilonorhynchidae . P. 417.
- ↑ Rowland: Bowerbirds . P. 87.
- ↑ Rowland: Bowerbirds . P. 85.
- ↑ Rowland: Bowerbirds . P. 88.
- ↑ a b Frith: The Bowerbirds - Ptilonorhynchidae . P. 418.
- ↑ a b Rowland: Bowerbirds . P. 89.
- ↑ Frith: The Bowerbirds - Ptilonorhynchidae . P. 422.
- ↑ a b Frith: The Bowerbirds - Ptilonorhynchidae . P. 420.
- ↑ Frith: The Bowerbirds - Ptilonorhynchidae . P. 423.