Ground woodpecker
| Ground woodpecker | ||||||||||
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Ground woodpeckers ( Geocolaptes olivaceus ), male on the right, female on the left |
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| Systematics | ||||||||||
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| Scientific name of the genus | ||||||||||
| Geocolaptes | ||||||||||
| Swainson , 1832 | ||||||||||
| Scientific name of the species | ||||||||||
| Geocolaptes olivaceus | ||||||||||
| ( Gmelin , 1788) |
The ground woodpecker ( Geocolaptes olivaceus ) is a species of bird from the family of woodpeckers (Picidae). The genus Geocolaptes is monotypical with the ground woodpecker as the only species. This medium-sized woodpecker species is endemic to South Africa , Swaziland and Lesothos and lives in open, rocky landscapes. The ground woodpecker is a highly specialized ground dweller, the food consists almost exclusively of ants nesting in the ground . The species is common and is classified by the IUCN as “least concern”.
description
Ground woodpeckers are medium-sized woodpeckers with a long, pointed beak that is very narrow at the base. The ridge of the beak is bent downwards. The body length is about 22-30 cm, the weight 105-134 g; they are thus in size between the great spotted and green woodpecker . Unlike most woodpecker species, the species shows only a weakly pronounced sexual dimorphism in terms of color .
The plumage of the nominate form is overall quite dark and poor in contrast. The upper and middle back and shoulder feathers are solid gray-brown to pale green-brown. The lower back is red, the upper tail-coverts and the upper side of the tail are clearly, but narrowly banded in white on a brown background. The upper wing-coverts are gray-brown and indistinctly lightly spotted and banded. The wings and umbrella feathers are banded in white on a dark brown background, the umbrella feathers have a greenish or grayish tinge. The breast plumage is white with broad pinkish-red tips and light, light stripes. Towards the belly and on the under tail-coverts, the feathers are darker and the tips are darker purple. The flanks are banded gray-brown and whitish, the banding is often extended to the lower tail-coverts. The lower wings are banded yellowish white on a brown ground, the underside of the tail on a light brown ground.
The beak is black, more gray at the base. Legs and toes are gray. The iris is pink, white or whitish towards the pupil .
The male's forehead and skull are brown-gray. The neck is more brown and occasionally shows a trace of red. The sides of the head and neck are gray, the stripe of the beard is darker gray with fine red tips that can only be seen from a short distance. The chin and throat are white. The females lack the red tips of the beard stripe.
Vocalizations
A number of sometimes very distinctive calls are known for the species. A loud, harsh screeching like “piir, piir, piir” sounds when you are alarmed. A noisy series of up to five “chick-skriiim” or “riih-chick, riih-chick” calls, which are reminiscent of the noises of a saw while sharpening with a file, presumably serve as contact and territory chant . During courtship, the animals call "Tschiuw-kii" .
distribution and habitat
The ground woodpecker is endemic to South Africa , Swaziland and Lesothos . The distribution area extends in a west-east direction from the northwest of the North Cape Province to the Province of Free State and to the north to the north of the Transvaal , to the west of Swaziland and the west of KwaZulu-Natal . The entire (forested) coastal strip in the southeast of South Africa is uninhabited. The size of the total distribution area is estimated at around 774,000 km².
The species inhabits open, rocky landscapes such as grassy slopes and hills with numerous rocks, grassland with rock ridges, mountain slopes and barren or eroded areas, but also similarly structured cultivated land, e.g. B. roadsides. The animals are predominantly found above 600 m above sea level, but also inhabit suitable habitats in the southwest of the area down to sea level.
Systematics
In addition to the nominate form, Winkler et al. yet another, but little differentiated subspecies:
- Geocolaptes olivaceus olivaceus ( Gmelin , 1788) ; central and western Cape Province.
- Geocolaptes o. Prometheus Clancey , 1952 ; largest part of the distribution area. Overall, but especially on the underside, much lighter than the nominate form.
Way of life
Ground woodpeckers live in pairs or small groups with around six birds. The activity areas of these couples or groups are 21 to 70 hectares in size. The animals search rocks in the same way as other woodpeckers search tree trunks and also use rocks as resting places and singing stations, often close to roads.
nutrition
Woodpeckers are highly specialized ant hunters, their diet consists of around 99% ants, their larvae and pupae. Approximately 95% of all prey animals fall into eight species of ants. Termites make up about 1% of the diet, other invertebrates such as insects or mites are only accidentally eaten. The search for food takes place predominantly by jumping or walking on the ground, every irregularity, crevice and hole and also every lower edge of rocks protruding from the ground is examined with targeted individual blows. Disruptive leaves and the like are thrown aside with the beak. When an underground nest of ants is found, the ground is perforated at this point with powerful blows, then the animals sink their beak into the ground and, in a characteristic rigid posture, pull the ants out of the nest with their tongue. Wood-dwelling ants are similarly preyed on by poking into dead wood.
The foraging for food is very efficient, the animals spend a maximum of a third of the day with two distinct activity peaks in the morning and in the late afternoon. The groups apparently know the ant nests within their area of action and only stay in a certain area for a maximum of three days.
Reproduction
Ground woodpeckers breed in pairs or trios. The breeding season runs from August to December. The caves are mostly dug by the male in the slopes of steep banks, erosion channels and between rocks. They consist of a 0.5 to 1.2 m long and 7.5 cm wide tube that opens into a nest chamber with a diameter of about 15 cm. These caves are often used for several years. The clutch comprises 2–5, mostly 3 eggs, which are incubated by both partners and possibly also by the helper bird. The nestlings are in turn fed by both parents and the helper, the young birds remain in the family unit after they leave the family until the start of the next breeding season.
Existence and endangerment
There is no information on the size of the world population, but the species is considered common in its range. It is classified as safe (“least concern”) by the IUCN .
swell
Individual evidence
- ↑ The Ground Woodpecker at BirdLife International
- ↑ Hans Winkler, David Christie and David Nurney: Woodpeckers. A Guide to the Woodpeckers, Piculets, and Wrynecks of the World. Pica Press, Robertsbridge 1995: p. 238
literature
- Hans Winkler , David 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. 70-71 and 237-238.
Web links
- Geocolaptes olivaceus in the Red List of Threatened Species of the IUCN 2009. Posted by: BirdLife International, 2009. Accessed on March 19 of 2010.
Other web links
- Videos, photos and sound recordings of Geocolaptes olivaceus in the Internet Bird Collection