Olive-backed woodpecker

Olive-backed woodpecker
	Olive-backed woodpecker ( Dinopium rafflesii )
Systematics
Class :	Birds (aves)
Order :	Woodpecker birds (Piciformes)
Family :	Woodpeckers (Picidae)
Subfamily :	Real woodpeckers (Picinae)
Genre :	Dinopium
Type :	Olive-backed woodpecker
Scientific name
	Dinopium rafflesii
	( Vigors , 1830)

The olive-backed woodpecker ( Dinopium rafflesii ) is a species of bird from the family of woodpeckers (Picidae). The medium-sized woodpecker species colonizes parts of Southeast Asia. Olive-backed woodpeckers inhabit pristine, moist to wet and dense evergreen tropical deciduous forests including bog forests and mangroves . The food sought in the lower and middle tree layers on tree trunks, lower crown branches, young trees and also on lying dead wood consists mainly of ants and especially their pupae and termites .

The species is generally only locally distributed in its area and not very common. Due to the rapid destruction of the primary rainforests in the entire area of distribution, the population is declining with a probability bordering on certainty, the olive-backed woodpecker is therefore classified by the IUCN as a type of warning list ("near threatened").

description

Olive-backed woodpeckers are medium-sized woodpeckers with a pronounced feather hood, a rather soft, long and slightly downwardly curved tail and a medium-long, chisel-shaped, pointed beak that is narrow at the base. The ridge of the beak is slightly bent downwards. The body length is 26-28 cm, the weight about 76-119 g. This makes them significantly larger, but only slightly heavier than a great spotted woodpecker . The species is colored richly and shows a clear sexual dimorphism with regard to the coloring .

In males of the nominate form , the uppermost back is black. The entire remaining upper side of the trunk including the rump and upper tail-coverts is dark olive-green with bronze or yellowish feathers, the rump and upper tail-coverts occasionally also show orange and rarely pale reddish tips. The upper wing coverts are similarly colored, but more bronze or yellowish olive green. The wings are brownish black, the arm wings have yellow-green outside flags and all wings are spotted white on the inside flags. The top of the tail is black, the underside olive-black. The entire underside of the trunk, from the lower throat to the under tail-coverts, is almost monochrome olive to greyish-olive, often with a rusty brown tone. The flanks are usually brightly spotted with white. The lower wings are spotted white on a dark brown background.

The forehead, crown of the head and bonnet are red with beige feathers, the red color is limited to a narrow black below. A wide, white stripe over the eyes extends from the top of the eye to the nape of the neck. Below that, a wide black eye stripe runs from the back of the eye to the nape of the neck. The yellowish beige rein stripe begins at the base of the beak, turns into white and extends backwards below the ear covers, then becomes very wide and runs as a white band over the sides of the neck to the upper sides of the chest. The cinnamon-brown, yellowish or rusty-yellow stripe of the beard beginning at the lower base of the beak turns into black just below the ear covers and then continues as a black front border of the white sides of the neck to the upper breast. The neck is black like the uppermost back; The chin and upper throat are beige-cinnamon brown, yellowish or rusty yellow like the beard stripe.

The beak is gray to gray-black, legs and toes are blue-gray or gray. The iris is dark red-brown.

The female has no red head; The skull and bonnet are black, the forehead more olive or beige. The hood is also slightly smaller than that of the male.

Systematics

The species is very variable, but only two subspecies are recognized, which only differ significantly in size:

Dinopium rafflesii rafflesii ( Vigors , 1830) - largest part of the range. Blade length 137–149 mm, weight 87–119 g.
Dinopium rafflesii dulitense Delacour , 1946 - Borneo . Smaller than the nominate shape in all dimensions , wing length 119–139 mm, weight 76–84 g.

Vocalizations

The most frequent calls are individual "chäk" sounds and quickly lined up series of these sounds, which are uttered in two versions. A slow “chäktschäktschäk-chäk” of 6 to 34 sounds that vary in speed and pitch and sometimes ended with an individual call obviously serves to communicate with the couple. A similar series of calls with 10 to 50 sounds, about 1.5 times as fast and more evenly, is probably used primarily to demarcate the territory. These series of calls are not dissimilar to those of the European green woodpecker . In intra-species disputes, a low "ch-wiii, ch-wiii, ch-wiii" is sometimes uttered , and a soft, almost trilling "ti-iii" and a squeaking "tiririt" are known. The species apparently does not drum, but breeding birds occasionally tap regular series of 10–12 blows with their beak.

distribution and habitat

This species of woodpecker inhabits parts of Southeast Asia. The strongly fragmented distribution area extends in a west-east direction from the south of Myanmar to the east of Borneo , in a north-south direction from the south of Myanmar to the southern tip of Sumatra . The size of the total distribution area is about 1,030,000 km².

Olive-backed woodpeckers inhabit pristine, wet, and dense evergreen tropical deciduous forests, including bog forests and mangroves . They usually avoid secondary forest and cleared areas. The animals are largely limited to the flat and hill country, the altitude range extends up to about 1200 m, on Borneo also up to 1600 m.

nutrition

The food sought in the lower and middle tree layers on tree trunks, lower crown branches, young trees and also on lying dead wood consists mainly of ants and especially their pupae and termites . The search for food takes place mainly by reading, less often by chopping.

Reproduction

Olive-backed woodpeckers live individually or in pairs, the partners keep in contact with each other through calls. The breeding season is hardly known and varies depending on the area of distribution; breeding birds were observed in Borneo in October, on the Malay Peninsula in April and May. The caves are also created in healthy wood. Both parents take part in cave construction and incubation, the male rests in the breeding cave. Further information on the breeding biology is not yet available.

Existence and endangerment

There is no information on the size of the world population. The species is generally only locally distributed in its large area and rarely found. In the last few decades, the forests in the lowlands of the Great Sunda Islands have been destroyed at a very rapid rate. The causes for this include the rampant illegal logging and the conversion into agricultural land. All remaining stocks with valuable timber became the target of this logging, also within protected areas. The population of the olive-backed woodpecker is therefore declining with a probability bordering on certainty, even if there is no concrete data on the extent of this decline. It is therefore classified by the IUCN as a type of warning list ("near threatened").

swell

Individual evidence

↑ Hans Winkler, David A. Christie and David Nurney: Woodpeckers. A Guide to the Woodpeckers, Piculets, and Wrynecks of the World. Pica Press, Robertsbridge 1995: pp. 372-373
↑ The Olive-backed Woodpecker at BirdLife International (online, accessed December 24, 2010)

literature

Hans Winkler , David A. Christie and David Nurney: Woodpeckers. A Guide to the Woodpeckers, Piculets, and Wrynecks of the World. Pica Press, Robertsbridge 1995, ISBN 0-395-72043-5 , pp. 152-153 and 372-373.

Web links

Dinopium rafflesii in the Red List of Threatened Species of the IUCN 2010. Posted by: BirdLife International, 2008. Accessed on December 24 of 2010.