Gray-breasted stubborn head
| Gray-breasted stubborn head | ||||||||||||
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Gray-breasted thick head of the subspecies Colluricincla harmonica strigata |
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| Colluricincla harmonica | ||||||||||||
| ( Latham , 1801) |
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The gray-breasted thickhead ( Colluricincla harmonica ) is a passerine bird from the genus Colluricincla within the family of the thickheads and is a representative of the avifauna of Australia and New Guinea . In Australia he is best known for his pleasant, melodious singing.
The IUCN classifies the population of the Graubrust-Dickkopfs as harmless ( least concern ). Several subspecies are distinguished.
description
The large-headed pectoral chest reaches a body length of 22 to 27 centimeters, a wingspan of 30 to 40 centimeters and a weight between 58 and 74 grams. It is one of the largest representatives within its genus and is reminiscent of a thrush with its physique. The brown-breasted thick-head is similar in size to the gray-breasted thick-head, but the gray-breasted thick-head is significantly more powerful. Compared to the gray-backed thick head and the forest thick head , the gray chest thick head is significantly larger. There is a slight gender dimorphism .
male
In the males, the crown and the back of the neck are dark gray. The sides of the head and the sides of the neck are lighter gray. The reins are white and contrast strikingly with the rest of the head plumage. The chin and the upper throat are whitish to very light gray and have no noticeable dashed lines. The coat, shoulders and back are brown and stand out conspicuously from the gray back neck. The rump, the upper tail-coverts and the tail plumage are gray.
The chest and the flanks are light gray to gray and merge into white in the middle of the abdomen. In some individuals, however, the middle of the abdomen is also light gray. The under tail-coverts are white with light gray dots, pure white or light gray with diffuse white spots. The beak is black, the iris is dark red-brown. The orbital ring is gray, dark gray or black gray. The legs and feet are dark gray to black.
female
The females are similar to the males, but differ in the head and neck plumage and the color of the beak. They have light gray reins that contrast only slightly with the rest of the head plumage. The eyes are surrounded by a light gray spring ring. The chin, throat and upper chest are individually dotted with different strengths, but the dotted lines are always more intense than in the males. The beak is gray to blue-gray with a darker tip.
Possible confusion
In the distribution area of the gray-breasted thick head, several types of thick head with which it can be confused. However, they all colonize different habitats, and unlike in the gray-breasted thick-headed species, the underside of the body is brownish in these species.
The brown-backed Dickkopf is built much slimmer than the Graubrust-Dickkopf and appears overall darker. The forest thickhead occurs in the rainforests of northwestern Australia and is significantly smaller. With him, the underside of the body is significantly darker than with the gray-breasted thick head. The gray-backed Dickkopf colonizes mountainous rainforests and is limited to the northeast of the Australian state of Queensland . In addition to its smaller body size, it also differs from the gray-breasted thick head in its tail plumage, which is proportionally shorter than its body size. From the bonnet thick head ( Oreoica gutturalis ) the gray breasted thick head differs among other things in the lack of the small feather bonnet. This species also has a significantly shorter beak, a shorter tail plumage and the females have an orange-colored iris.
Distribution area of the individual subspecies and habitat
The pigheaded bird is widespread in Australia and Tasmania and is one of the most famous songbirds on the Australian continent. It is also found on several islands off the Australian coast and also colonizes the coastal regions of the eastern half of New Guinea.
There are five subspecies:
- C. h. brunnea - Gould , 1841 : Originally described as a separate species. Occurrence in the north of Australia and on Melville Island .
- C. h. superciliosa - Masters , 1876 : Originally described as a separate species. Occurrence in the east of New Guinea, on islands of the Torres Strait and in the northeast of Australia.
- C. h. harmonica - ( Latham , 1801) : Found in eastern Australia.
- C. h. strigata - Swainson , 1838 : Originally described as a separate species. Occurrence in Tasmania and the islands of the Bass Strait .
- C. h. rufiventris - Gould, 1841 : Originally described as a separate species. Occurrence in the west, south and inland areas of Australia.
The gray-breasted thick head is a resident bird in its entire range .
habitat
The gray-breasted thickhead colonizes different forest types and is particularly common in those dominated by eucalyptus trees or - in the interior of Australia - by acacia trees. It is usually not found in the dense rainforest. Otherwise, it is a very adaptable species that populates all climatic zones and landscapes from the coastal zone to the arid plains inland. It is also one of the typical birds of the Australian mallee .
In the east of Australia, the gray-chested stubborn head is also more common in urban regions, provided there is still indigenous vegetation there. In contrast, it is rare in populated regions in western Australia. In western Australia, increasing settlement and deforestation in favor of agricultural land has led to a decline in the population.
food
The gray-breasted thick head is an omnivore, which covers most of its food needs with invertebrates. It also eats vertebrates such as small frogs, small lizards, bird eggs, nestlings and adult small songbirds as well as small mammals. But it also eats fruits and seeds. The area in which it looks for food extends from the ground to the top of the tree canopy. It finds most of its food when it searches foliage and branches for prey. During its foraging, it occasionally travels loose bark from the tree trunks and branches or uses its beak to look for insects in small indentations in the branches and trunks. While foraging for food, it moves forward both in the branches and hopping on the ground. The flight, on the other hand, is straight with a powerful wing beat, which is repeatedly interrupted by short gliding phases.
While foraging, it is occasionally associated with other insectivorous species. The species with which it occasionally searches for food together include the white-throated tree-slide , the large-headed flycatcher , the New Zealand fan-tail and the striped panther bird .
Way of life
The gray-chested stubborn lives solitary or in pairs. After the breeding season, it can also be observed regularly in small family groups. It is an inconspicuous, but comparatively trusting bird, whose presence is usually noticeable primarily through its loud singing or loud calls. Both singing and the calls can be heard from a further distance.
It has not yet been adequately investigated whether the gray-chested stubborn person enters into a relationship of several years. However, it has repeatedly been observed that couples occupied the same territory for several years. The longest observed relationship was over five years. All year round, couples defend an area that is used as feeding and breeding area.
The breeding season falls from July to February. They usually build their nests well hidden in the thicket of climbing plants or in the thick foliage of trees. They also like to use tree hollows. Nests that are not built in cavities can be comparatively large and are made from strips of bark, twigs, grass, leaves, roots and the like. If, on the other hand, they nest in natural tree hollows, the nest is only limited to a flat, padded hollow. Both parent birds are involved in the construction. The clutch comprises one to four eggs. Both parent birds breed and begin the breeding business as soon as the clutch is complete. The breeding season is just under 17 days. The nestlings fledge after 17 to 18 days.
Life expectancy
On the basis of data that could be obtained by ringing large-headed gray breasts, it is known that this species can live at least 12 years. So far, the age record has been held by a female who was ringed in southern Australia on December 7, 1977 and was recaptured for 12 years and 6 months not far from the original ringing location.
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 .
- 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
- ↑ a b c d Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 6, p. 1191.
- ↑ Handbook of the Birds of the World zum Graubrust-Dickkopf , accessed on July 3, 2017
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 6, p. 1189.
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 6, p. 1192.
- ^ IOC World Bird List 6.3 . In: IOC World Bird List Datasets . September. doi : 10.14344 / ioc.ml.6.3 .
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 6, p. 1193.
- ↑ a b c d Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 6, p. 1195.
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 6, p. 1196.
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 6, p. 1204.