Gray-backed stubborn head
| Gray-backed stubborn head | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Gray-backed stubborn head |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Colluricincla boweri | ||||||||||||
| Ramsay , 1885 |
The gray-backed thickhead ( Colluricincla boweri ) is a passerine bird from the genus Colluricincla within the family of the thickheads and is a representative of the avifauna of Australia .
The IUCN classifies the stock situation of the gray-backed thick head as safe ( least concern ). No subspecies are distinguished.
description
The gray-backed thick head reaches a body length of 19.5 to 21 centimeters and a weight between 39 and 48 grams. It is therefore a medium-sized species within the stubborn family and is reminiscent of a thrush. The head is large in relation to the body and the tail plumage is proportionally small. There is a slight gender dimorphism.
male
In the males, the vertex and the sides of the head as well as the neck, the upper body and the upper side of the tail plumage are monochrome dark brown-gray. The reins are pale gray. In some individuals there is also a diffuse, pale reddish-brown stripe above the eyes, which runs from the forehead to just above the eye. The chin is cream-colored, the rest of the underside of the body is matt red-brown with individually differently pronounced gray dots on the throat and chest. The tail plumage is brownish gray on the underside. The beak is black, the iris is red-brown. The orbital ring is gray. The legs and feet are blue-gray.
female
The females are largely similar to the males, but have a broad red-brown stripe over the eyes that runs from the frontal sides to behind the eye. The eye is also surrounded by a reddish-brown spring ring, which, however, is not completely closed. This spring ring is completely absent in the males. The reins are cream colored in the females and not gray as in the males. The beak is more dull than that of the males and is dark gray to blackish gray. The iris is dark brown with a slightly less pronounced shade of red than that of the males.
Possible confusion
In the distribution area of the gray-backed Dickkopf also occurs the forest-Dickkopf , which superficially resembles the Gray-backed Dickkopf. However, the two species can be found at different altitudes: The forest thickhead rarely occurs above 600 meters and is not found in the interior of rainforests. It is also slimmer and has a proportionally longer tail than the gray-backed thick head. It also shows no or only very indistinct dots on the breast and throat feathers.
Distribution area and habitat
The gray-backed thickhead occurs exclusively in the damp rainforests in the northeast of the Australian state of Queensland. The northern limit of distribution is south of Cooktown and the Paluma Range and extends to the Atherton Tableland .
In its area of distribution, the gray-backed thickhead colonizes tropical mountain rainforests. It occurs in both primary and secondary forests . The wandering movements of the gray-backed thick head have not yet been conclusively investigated. However, it is considered to be a resident bird - the few data that could be obtained from ringed and recovered birds indicate a high degree of local loyalty.
Way of life
The gray-backed thick head lives solitary or in pairs. Occasionally it is also associated with the tooth arbor bird . It often stays close to the ground and is basically an inconspicuous bird that reveals its presence primarily through its calls.
The diet consists exclusively of insects that it finds in the foliage of trees. While foraging for food, it stays mostly in the lower area of the forest.
The breeding season falls from October to January. Young birds are observed from November to January. The nest is usually in a fork of a branch or in a dense thicket of climbing plants. The nest is cup-shaped and is built from small branches, roots, dead leaves and parts of fern fronds. The clutch usually consists of two eggs. The parent birds usually raise two clutches in one breeding season. Both parent birds breed. The incubation period and the time it takes for the nestlings to fledge are not known.
Life expectancy
Gray-backed stubborn heads have a life expectancy of at least seven years.
literature
- PJ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds , Volume 6, Pardalotes to shrike-thrushes, Oxford University Press, Oxford 1993, ISBN 0-19-553069-1 .
Web links
Single receipts
- ↑ Handbook of the Birds of the World on Graurücken-Dickkopf , accessed on July 2, 2017
- ↑ a b Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 6, p. 1180.
- ↑ a b c Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 6, p. 1181.
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 6, p. 1183.
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 6, p. 1182.