Bécasse des bois

Identification

Adults are 33–38 cm (13–15 in) in length, including the 6–8 cm (2.4–3.1 in) long straight bill, and have a 55–65 cm (22–26 in) wingspan. The Eurasian woodcock has cryptic camouflage to suit its woodland habitat, with intricately patterned reddish-brown upperparts and buff underparts. The head is barred with black, not striped like that of its close relatives, the snipe. It has large eyes located high on the sides of its head, giving it 360-degree monocular vision.<p>The wings are rounded and the base of the bill is flesh-coloured with a dark tip. The legs vary from grey to pinkish. The species is sexually dimorphic, with the male much larger than the female, although the sexes cannot be separated in the field.

Taxonomie

The Eurasian woodcock was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the current binomial name Scolopax rusticola. The genus name is Latin for a snipe or woodcock. The specific epithet rusticola is the Latin name of a gamebird mentioned by Pliny the Elder and Marcus Valerius Martialis. It was possibly a grouse. The species is monotypic: no subspecies are recognised. Its closest relatives are the other woodcocks in the genus Scolopax.

Nom scientifique

Scolopax rusticola

Autorité

Linnaeus, 1758

Ordre

Charadriiformes

Famille

Scolopacidés

Genre

Scolopax

Répartition et habitat

About one third of the world's Eurasian woodcock breed in Europe, with more than 90% of the continent's population breeding in Russia and Fennoscandia. Their breeding range stretches from Fennoscandia to the Mediterranean Sea and Canary Islands and from western Europe to Russia. The population on the Azores is isolated from mainland Europe, resulting in subtle genetic differentiation.<p>This species is the woodcock found through most of temperate and subarctic Eurasia. Northern and Asian populations migrate to southern Europe or the Indian Subcontinent, respectively. Birds in milder western European countries and on Atlantic islands are resident. The populations breeding in north-west and southern Europe are mostly sedentary. The birds' spring migration commences in February; breeding territories are reached between March and May. Spring migration movements of woodcock are influenced by weather conditions, however this does not have a major effect on their subsequent breeding success.<p>The Eurasian woodcock has a large range, with an estimated Global Extent of Occurrence of 10 million square kilometres and a population of an estimated 15 million to 16 million birds. Because of its large range, stable population trend and large population size, the species has been evaluated as Least Concern. The most important threat to the population of the Eurasian woodcock in the breeding range is the increased fragmentation of its woodland habitat. At other times of year, a reduction in the amount of permanent grassland and an increase in the intensification of farming are also threats, and the species' susceptibility to avian influenza may have an impact in future.<p>The Eurasian woodcock's required breeding habitat is large, unfragmented areas of broadleaved deciduous or mixed broadleaved and coniferous forest, with dense undergrowth of plants such as brambles, holly, hazel, gorse, bracken, or bilberry. On a small scale, Eurasian woodcock appear to prefer woods containing birch and were less likely to be found in beech dominated woods. They also prefer woods further away from urban areas. Breeding territories must include a mix of dry, warm resting places, damp areas for feeding, and clearings for flight. In larger woods, wide "rides" (open tracks through the wood) and small clearings are important. In winter, Eurasian woodcock also use scrubland during the day but in freezing weather they may use intertidal mud.

Aire de reproduction

PAL : widespread subarctic to temperate and montane subtropical moist forests of Palearctic: British Is. n to Scandinavia (except far n) s to n Iberian Pen., Azores, Madeira and w, c Canary Is. (Macaronesia, nw of w Africa), e through temperate Russia, ne Kazakhstan, n Xinjiang (nw China), n Mongolia, ne China, Amurland and Sakhalin (se Russia), and Hokkaido to c Honshu (n, c Japan); disjunctly in the Caucasus and Himalayas

Aire hors reproduction

OR, n AF : temperate to subtropical Eastern Hemisphere woodlands: to Iberian Pen., n Africa, n Middle East, sw India, n se Asia, e China, Taiwan, Korean Pen. and c, s Japan

Migration

Complete migrants

Comportement

Eurasian woodcock are crepuscular (most active at dawn and dusk) and rarely active during the day unless flushed, when they fly off with a whirring wing noise. The flight is somewhat owl- or bat-like; woodcock fly fast and directly while migrating or crossing open country, but fly erratically with twisting and fluttering once in woodland. They are usually solitary and migrate singly, but may congregate when weather or geographical conditions force them to do so. This species is parasitised by the moorhen flea, Dasypsyllus gallinulae.<p>The male performs a courtship display flight called 'roding' at dusk between April and June. A mating call is performed during courtship display flights: orr, orr, orr, pist. A study of spectrograms of the vocalisations of male Eurasian woodcock showed that 95% of calls could be attributed correctly to individual birds, and concluded that counting roding males was a suitable method of monitoring the population. Roding surveys are now used for population estimates in a range of countries including Britain, Switzerland, France and Russia.<p>Eurasian woodcock nest on the ground in low cover in woodland or tall heather. The nest is a lined cup or a slight hollow lined with dead leaves and other plant material. A single brood of one or two white or creamy eggs with light brown and grey blotches is laid; once the clutch is complete, incubation is performed by the female for between 21 and 24 days. The eggs measure 44 mm × 34 mm (1.7 in × 1.3 in) and weigh .mw-parser-output .frac{white-space:nowrap}.mw-parser-output .frac .num,.mw-parser-output .frac .den{font-size:80%;line-height:0;vertical-align:super}.mw-parser-output .frac .den{vertical-align:sub}.mw-parser-output .sr-only{border:0;clip:rect(0,0,0,0);clip-path:polygon(0px 0px,0px 0px,0px 0px);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}26.5 g (7⁄8 oz), of which 5% is shell. The downy, precocial young leave the nest immediately and fledge after 15–20 days, although they can fly short distances after 10 days. When threatened, the mother bird can fly whilst carrying small chicks between her legs, body and tail, in her claws or on her back. This behaviour is rarely witnessed.<p>Eurasian woodcock forage in soft soil in thickets, usually well hidden from sight. They mainly eat earthworms, but also insects and their larvae, freshwater molluscs and some plant seeds. Because they rely on probing into the ground to find food, they are vulnerable to cold winter weather when the ground remains frozen. During the cold British winter of 1962–63, starving woodcock were found feeding in urban areas and some were even forced to eat bird seed.<p>Nocturnal feeding occurs in frost-free pasture or long-rotation grass meadows; fields with woodland within 1 km (0.62 mi) are preferred to allow roosting during the day. There are only low densities of Eurasian woodcock in predominantly arable areas. In a three-year scientific study based in Brittany, France, 65 radio-tagged woodcock and their habitat preferences were monitored. During the day, the birds chose areas of forest with humus which held large numbers of earthworms and with a dense scrub layer to provide protection, and hedges with scrub and trees were also found to be important. At night, the woodcock selected grazed pastures which had five times the biomass of earthworms compared to tilled land.

Conservation

Tendance de la population

stable