Eurasian Stone-curlew

Informazioni

The Eurasian Stone-curlew, also known as the Stone-curlew or Thick-knee, is a medium-sized, nocturnal wader with a distinctive large head, prominent yellow eyes, and cryptic plumage. It is known for its haunting, wailing calls, particularly at dusk and dawn. Despite its wader classification, it prefers dry, open habitats rather than wetlands.

Dimensioni e longevità

Lunghezza

38-46 cm

Apertura alare

76-88 cm

Peso

290-535 g

Longevità

Up to 15 years in the wild

Dieta

Carnivore (primarily invertebrates and small vertebrates)

Caratteristiche fisiche

Piumaggio

Cryptic sandy-brown to grey-brown plumage, heavily streaked with dark brown and black, providing excellent camouflage against stony or bare ground. The underparts are paler, whitish, with dark streaking on the breast. It has a prominent white supercilium and a dark eye-stripe. The wings show two distinct white bars bordered by black, particularly visible in flight.

Forma del becco

Relatively short, stout, and strong bill, yellowish at the base and black at the tip.

Colore degli occhi

Large, prominent, bright yellow eyes, adapted for nocturnal vision, surrounded by a yellow orbital ring.

Colore delle zampe

Long, thick, yellowish-green legs with noticeably swollen 'knees' (actually ankles), giving rise to the common name 'Thick-knee'.

Caratteristiche distintive

Large yellow eyes, thick 'knees', cryptic plumage, and distinctive white and black wing bars in flight. Its upright stance and large head are also characteristic.

Aspetto giovanile

Juveniles resemble adults but have a slightly duller plumage with more extensive buff or rufous fringing on the feathers, giving them a scaly appearance. The streaking may be less defined, and the eye color might be less intense yellow.

Cambiamenti stagionali

No significant seasonal plumage changes. Plumage remains consistent throughout the year, optimized for camouflage.

Dimorfismo sessuale

Males and females are generally monomorphic in plumage and size, making them difficult to distinguish visually in the field.

Come identificare

1. 1

   Overall Appearance

   Look for a medium-sized, rather upright bird with long legs, a large head, and a relatively short, stout bill. Its cryptic sandy-brown plumage with dark streaking is key for camouflage.

2. 2

   Eyes

   The most striking feature is its large, prominent, bright yellow eyes, often described as 'glowing' at night. These are surrounded by a yellow orbital ring.

3. 3

   Legs

   Note the long, thick, yellowish-green legs with distinctively swollen 'knees' (ankles).

4. 4

   Plumage Details

   Observe the dark streaking on the upperparts and breast, and the prominent white supercilium above the eye. In flight, look for the two distinct white wing bars bordered by black on the primaries.

5. 5

   Behavior

   Often active at dusk and dawn, and throughout the night. During the day, it is usually motionless, relying on camouflage. Its characteristic slow walk, pause, and dash hunting technique is also a good clue.

6. 6

   Vocalization

   Listen for its unmistakable, loud, mournful, wailing 'cur-lee' call, especially at night. This is often the first indication of its presence.

Habitat e areale

Biomi

Temperate grasslands, semi-deserts, steppes, open woodlands, agricultural lands.

Areale geografico

Widespread across Europe, North Africa, and Southwest Asia. In Europe, it breeds from the Iberian Peninsula eastwards to Russia, and south to the Mediterranean. Northern populations are migratory, while southern populations are often resident.

Fascia altitudinale

Typically found from sea level up to approximately 1,500 meters, though generally prefers lower elevations.

Ambienti preferiti

Dry, open, sparsely vegetated areas with stony or sandy soils, fallow fields, heathland, chalk downland, steppe, and sometimes open pine forests. Avoids dense vegetation and wetlands.

Comportamento

Periodo di attività

Predominantly nocturnal and crepuscular, becoming active at dusk and remaining so through the night. During the day, they are cryptic and often remain motionless, relying on their camouflage.

Abitudini alimentari

Primarily nocturnal or crepuscular feeder, foraging for a wide variety of invertebrates such as insects (beetles, crickets, grasshoppers), worms, and molluscs. It also preys on small vertebrates including lizards, frogs, small rodents, and bird chicks. It hunts by walking slowly, pausing, and then making a sudden dash to catch prey.

Comportamento sociale

Typically solitary or found in pairs during the breeding season. Outside of breeding, they may form small flocks, especially during migration or at communal roosting sites.

Tipo di volo

Strong, direct flight with rapid wing beats. In flight, the prominent white wing bars bordered by black are very conspicuous. It often flies at low altitudes.

Migrazione

Northern and eastern European populations are migratory, moving to North Africa and the Middle East for the winter. Southern European and North African populations are largely resident or undertake short-distance movements. Migration occurs mainly at night.

Territorialità

Territorial during the breeding season, with pairs defending a nesting area. Displays include calling, posturing, and sometimes short chases.

Riproduzione

Stagione riproduttiva

Typically from March to July, varying geographically.

Abitudini di nidificazione

Nests are simple scrapes on the bare ground, often near a stone, clump of vegetation, or animal droppings for camouflage. No nest material is added, though sometimes small pebbles or bits of debris may line the scrape. Nests are usually in open, dry areas.

Dimensione della covata

1-3 eggs, most commonly 2.

Descrizione dell'uovo

Usually 2 eggs (occasionally 1 or 3), oval to pyriform in shape. They are pale buff, stone-colored, or olive-brown, heavily marked with dark brown, black, and grey blotches and streaks, providing excellent camouflage against the ground.

Periodo di incubazione

24-27 days, primarily by the female, though the male may assist.

Periodo di involo

Chicks are precocial and leave the nest scrape shortly after hatching. They are able to feed themselves within a few days but are cared for by both parents for 36-42 days until they can fly.

Cure parentali

Both parents share incubation duties (though female predominates) and care for the precocial young. Parents are highly protective and will perform distraction displays to lure predators away from the nest or chicks.

Dove trovarlo

Consigli sul campo

1. Go at Dusk or Dawn. This species is primarily nocturnal and crepuscular. Your best chance of seeing or hearing them is during the twilight hours or even at night with a spotlight (used responsibly and without disturbing the birds).
2. Listen for Calls. Their distinctive, haunting 'cur-lee' call is often the easiest way to detect their presence, especially when they are camouflaged during the day.
3. Scan Open Ground. Use binoculars to scan large expanses of open, dry, stony, or sandy ground. They blend in incredibly well, so patience is key.
4. Look for Movement. While they often stand still, look for subtle movements like head bobs or short dashes when they are foraging.
5. Check Agricultural Areas. Fallow fields, stubble fields, and areas with minimal crop cover are prime habitats, especially in agricultural landscapes.

Specie simili

Fatti rapidi

Activity:

Nocturnal/Crepuscular

Diet:

Invertebrates and small vertebrates

Habitat:

Dry, open, sparsely vegetated areas

Key Feature:

Large yellow eyes, cryptic plumage

Call:

Haunting 'cur-lee' wail

Curiosità

• The name 'Stone-curlew' refers to its preference for stony habitats and its curlew-like call, despite not being closely related to true curlews.
• Its large yellow eyes are an adaptation for excellent night vision, allowing it to hunt effectively in low light conditions.
• The 'thick-knee' part of its common name comes from the prominent, swollen appearance of its tarsal joints (ankles), which are often mistaken for knees.
• When threatened, it often freezes, relying entirely on its superb camouflage to avoid detection. If approached too closely, it may run or fly a short distance.
• In some cultures, its nocturnal calls are associated with ghosts or spirits due to their eerie, wailing quality.

Classificazione scientifica

Regno

Animalia

Phylum

Chordata

Classe

Aves

Ordine

Charadriiformes

Famiglia

Burhinidae

Genere

Burhinus

Specie

B. oedicnemus

Esplora Eurasian Stone-curlew