Line woodpecker

Line woodpecker
	Line woodpecker ( Dryocopus l. Erythrops ), male
Systematics
Class :	Birds (aves)
Order :	Woodpecker birds (Piciformes)
Family :	Woodpeckers (Picidae)
Subfamily :	Real woodpeckers (Picinae)
Genre :	Dryocopus
Type :	Line woodpecker
Scientific name
	Dryocopus lineatus
	( Linnaeus , 1766)

The line Woodpecker ( Dryocopus lineatus ) is a species of bird from the family of woodpeckers (Picidae). The large distribution area of the species extends from Mexico over almost all of Central America and large parts of northern South America to Paraguay and to the northeast of Argentina . The line woodpecker lives in a wide range of moist, medium-moist and semi-dry forest types, with more open areas such as clearings, forest edges and secondary forest being preferred overall. However, the species also colonizes cultivated land such as shady gardens, tree groves and tree-lined meadows. The food sought in all tree layers, especially on trunks and strong branches, consists of beetles and their wood-dwelling larvae, ants and their brood, as well as caterpillars and also the egg packets of grasshoppers. Line woodpeckers also eat seeds and fruits.

The species has benefited from ongoing forest destruction and conversion due to its preference for more open habitats and the population is believed to be increasing. The line woodpecker is therefore classified by the IUCN as (= least concern - not endangered).

description

The line woodpecker is similar in habit to the black woodpecker , which is also native to Central Europe , but is considerably smaller and the color differs significantly. Depending on the subspecies, they are medium-sized to quite large woodpeckers with a long and stiff tail, which is bent forward towards the tip, and a pronounced feather hood pulled backwards. The beak is long, chisel-shaped and pointed and broad at the base. The ridge of the beak is bent downwards. The body length is 30–36 cm, the weight 136–264 g; they are thus slightly larger than a green woodpecker , but about as heavy as this one. The species shows a clear sexual dimorphism in terms of coloration , females are also slightly smaller than the males.

In males of the nominate form Dryocopus l. lineatus , the entire upper surface of the trunk including the upper tail-coverts as well as the upper wing coverts and the upper tail are black. The shoulder feathers have black inside and white outside flags , the latter forming a white shoulder stripe. Usually the wing bend also shows a whitish field. The wings are also black on the top with a white field at the base of the inner flags; In the fresh plumage, the hand wings also have white tips.

The chest is black, occasionally the black color extends to the abdomen. Mostly, however, the belly, flanks and lower tail-coverts are banded variably brownish-black on a grayish beige to whitish background. The wings are blackish underneath with whitish bases; the whitish or light beige under wing-coverts often show a small black spot. The under tail is brownish black.

Female of the subspecies Dryocopus l. erythrops departing from cave.

The forehead, top and back of the head as well as the long bonnet are bright red, occasionally some dark gray feather bases can be seen here. The upper rein region, the area below and above the eye as well as the ear covers up to the neck are blackish, rarely a narrow, white eye stripe beginning behind the eye is formed. A wide white band runs from the lower rein region to the rear, lower border of the ear covers and over the side of the neck to the upper side of the chest. The beard stripe is mostly red at the front, black further back. It widens towards the back of the cheeks and runs down the side of the neck to the side of the chest. The chin and upper throat are white and therefore show black dots of variable thickness.

Females lack the red in the beard stripe and the forehead and front upper head are also monochrome black.

The bill is gray to gray-black with a lighter lower bill and usually a dark tip. Legs and toes are gray with a shade of green, blue, or yellow, sometimes with an olive shade. The iris is white or pale orange, the eye ring is brown.

Vocalizations

The most frequent call is a loud, explosive, penetrating and far-reaching series of around 30 sounds such as "wicwic-wicwicwic ..., wuk wuk wuk, äk-äk-äk ..., kjah-jik-jik-jik" or "wiip wiip wiip ” , which drops off at the end. In addition, individual calls such as a loud and sharp "pik" as well as rattling calls introduced with this sound are known, which depending on the author with "kip-whurrr" , "pik-urrrr-rr" , "ik-rrrrr" , " cuchrrrrrr " , " ch'whirrr " or " k'rroo " . Both sexes drum; A drum verse begins with five to eight slowly successive beats, followed by a long drum roll with increasing beat frequency.

distribution and habitat

The large distribution area of the species extends from Mexico over almost all of Central America and, with the exception of the high elevations of the Andes, over large parts of northern South America to Paraguay and to the northeast of Argentina . The size of the total distribution area is estimated at 13.8 million km².

The line woodpecker lives in a wide range of moist, medium-moist and semi-dry forest types, with more open areas such as clearings, forest edges and secondary forest being preferred overall. However, the species also colonizes cultivated land such as shady gardens, tree groves and tree-lined meadows.

Systematics

Winkler et al. recognize five very variable subspecies:

Dryocopus l. lineatus ( Linnaeus , 1766) - Largest part of the range; Central America from Costa Rica to the south and northern South America. The subspecies is described above. The subspecies showed a slight decrease in size in the south-east and in the north of the area. The northernmost populations show a tendency to more beige and more irregular banding on the underside, and the beak is a bit lighter.

Dryocopus l. scapularis ( Vigors , 1829) - western Mexico . Smaller than nominate form and than Dryocopus l. similis , slight increase in size to the north. In contrast to all other subspecies, the white head and neck stripes are missing or are only very indistinct. The beak is bright.

Dryocopus l. similis ( Lesson , 1847) - From east and south Mexico to south to Costa Rica. Base color of the underside clearly beige. The beak is bright.

Female of the subspecies Dryocopus l. erythrops , here an individual with a missing white shoulder stripe.

Dryocopus l. erythrops ( Valenciennes , 1826) - south of the distribution area, in Brazil from Espírito Santo and São Paulo to Rio Grande do Sul , also west of Paraguay and north-east Argentina. Larger than populations of the nominate form to the north. In animals in the southern area of the subspecies, the shoulder stripe formed by the white shoulder feathers is missing. In northern animals it can be present or absent, whereby the proportion of birds with a stripe increases with increasing approach to the area of the nominate form. As an exception, the shoulder stripe can only be partially present. The population in the vicinity of the Iguazu in northern Argentina often shows a lot of reddish brown as the base color of the underside. The beak is dark.

Dryocopus l. fuscipennis Sclater , 1860 - extreme west of the distribution area in South America, western Ecuador and northwestern Peru . Smaller than nominate form. The upper side, which is black in other subspecies, is deep brown, the chest ash gray and the rest of the underside of the trunk rather beige with indistinct and irregular brown banding. The keels of the wings and the control feathers are light, the outer control feathers show a yellowish brown sheen on the underside. The beak is dark.

According to Winkler et al. the line woodpecker forms a super species with the helmet woodpecker ( Dryocopus pileatus ) and the black-bellied woodpecker ( Dryocopus schulzi ).

Way of life

Line woodpeckers are mostly found in pairs with call contact or in family groups with four to six birds. The foraging takes place in all tree layers and mostly on trunks and larger branches, occasionally also on the ground. Line woodpeckers also regularly look for isolated trees in the open landscape.

Female in a cave

The food consists of beetles and their wood-dwelling larvae, ants and their brood as well as caterpillars and also the egg packets of grasshoppers. Line woodpeckers also eat seeds and fruits. Food objects are obtained primarily by hammering and chopping and then probing, with the species making deep holes in both living and rotting wood. These woodpeckers also regularly chop off bark from dead trunks and branches. Fruits are also picked from thin branches in the treetops, leaves are thrown aside with their beak on the ground.

The breeding pairs live together all year round. The breeding season is different depending on the distribution area. In Colombia the species breeds at the end of the dry season in January and February, in Panama in March and April, in Belize in April and May and in Trinidad and Suriname from February to April. In the southern part of the range, breeding takes place from July to November.

The cave is preferably built in tree stumps with a small diameter (18-23 cm) at a height of 2 to 27 m. Toucans are major competitors in the occupation of caves. The clutches contain two to three eggs, the young birds are fed with food that has been choked out.

Existence and endangerment

Reliable information on the size of the world population is not available, it is estimated very roughly by BirdLife International at 5 to 50 million individuals. The species has benefited from ongoing forest destruction and conversion due to its preference for more open habitats and the population is believed to be increasing. The line woodpecker is therefore classified by the IUCN as safe ("least concern").

swell

Individual evidence

↑ ^a ^b The line woodpecker at BirdLife International . Retrieved July 1, 2011.
↑ Hans Winkler, David A. Christie and David Nurney: Woodpeckers. A Guide to the Woodpeckers, Piculets, and Wrynecks of the World. Pica Press, Robertsbridge 1995: p. 339
↑ Hans Winkler, David A. Christie and David Nurney: Woodpeckers. A Guide to the Woodpeckers, Piculets, and Wrynecks of the World. Pica Press, Robertsbridge 1995: p. 338

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. 132-133 and 338-340.