Stone curlew
The stone curlew, commonly referred to as the thick-knee, is a distinctive bird known for its large yellow eyes and unique knobby knee joints. This bird reaches a length of about 1.5 feet (45 centimeters) and weighs around one pound (0.5 kilograms), with a wingspan ranging between two to three feet (60 to 90 centimeters). Stone curlews are primarily nocturnal feeders, preying on a variety of insects, earthworms, and small vertebrates, which they skillfully catch using their long, slender bills.
Their breeding behavior includes elaborate courtship displays, and they typically nest in shallow scrapes in the ground, laying two to three eggs. The young are cared for by both parents and are protected from predators through protective behaviors that include feigning injury. Unfortunately, the stone curlew population has declined in parts of Europe primarily due to habitat destruction. These birds thrive in warm, dry habitats with sparse vegetation, making them well-adapted to their environment. Species within the stone curlew family exhibit a variety of adaptations and behaviors, highlighting their ecological significance.
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Stone curlew
The stone curlew is also known as the thick-knees. It received this name due to its knobby knee joints. But the most noticeable feature of the stone curlew is its bright yellow eyes. In parts of Europe, the stone curlew population has decreased due to the destruction of its habitat.
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Burhinidae
Genus: Oxyruncus
Species: Cristatus
The stone curlew reaches a length of about 1 1/2 feet (about 45 centimeters) and a weight of about one pound (1/2 kilogram). Its wingspan measures two to three feet (60 to 90 centimeters). The plumage, or feathering, of the stone curlew is light buff and gray with dark brown, black, and white streaks. The eyes are yellow and quite large. The stone curlew has a small, slender bill.
The stone curlew lives mostly on a diet of insects and their larvae. This includes beetles, grasshoppers, crickets, earwigs, flies, and moths. It also eats earthworms, slugs, snails, frogs, small lizards, mice, voles, and bird's eggs. The stone curlew mostly feeds between dusk and dawn. It has excellent eyesight and hearing, enabling it to spot prey at night. After the stone curlew spots its prey, it quickly chases it, flapping its wings to gain speed. The bird stabs the prey, spearing it with its long bill.
Stone curlews often form pairs in the spring and travel to their breeding grounds. Others find a mate at the breeding grounds after engaging in courtship displays. A male courts a female by deeply bowing, fanning out his tail, and touching his bill to the ground. A pair defends territory by standing with their bodies held stiff and upright, their tail feathers opened widely. The two stretch their bodies outward toward an approaching enemy and often chase and fight off the assailant.
The nest of the stone curlew consists of a deep scrape in the ground. The nest is positioned so the birds have a good view of their surroundings and any predators. After the birds mate, the female lays two to three pale buff eggs. The beach stone curlews and the great stone curlews lay a single egg. She and the male incubate the eggs for 24 to 27 days. If the birds are disturbed at the nest by a predator, they often lure the enemy away by faking injury, falling to the ground with their wings held out as if broken. The stone curlews are very protective of their young. They have been known to drive away sheep and cattle that stumble too close to their nest.
After hatching, the young are looked after by both the male and female. The young remain under the watchful eye of their parents for five to six weeks, after which time they are ready to fly.
The stone curlew lives in warm, dry habitats. In Europe, it makes its home on open, stony ground with short vegetation like areas where sheep graze. Other stone curlews live along dunes in dry, muddy areas and semi-desert habitats.
The stone curlew is more comfortable running along the ground than taking to the air. The bird mostly moves at night and rests during the day. If the bird is alarmed, it sits completely motionless. The bird's plumage and ability to sit very still make it difficult to spot.
The call of the stone curlew is a series of "kur-lee" sounds.
The average lifespan of stone curlews is six years, but some have lived more than 20 years in captivity.
Species include:
Beach stone curlew or beach thick-knee Esacus magnirostri
Bush stone curlew or bush thick-knee Burhinus grallarius
Double-striped thick-knee Hesperoburhinus bistriatus
Eurasian stone curlew or thick-knee Burhinus oedicnemus
Great stone curlew or great thick-knee Esacus recurvirostris
Indian stone curlew or thick-knee Burhinus indicus
Peruvian thick-knee Hesperoburhinus superciliaris
Spotted or Cape thick-knee or spotted dikkop Burhinus capensis
Senegal thick-knee Burhinus senegalensis
Water thick-knee or dikkop Burhinus vermiculatus
Bibliography
"Bush Stone-Curlew." Department for Environment and Water, Government of South Africa, cdn.environment.sa.gov.au/landscape/docs/hf/bush-stone-curlew-bio-region-fact.pdf. Accessed 15 May 2024.
"Stone-Curlew." British Trust for Ornithology, www.bto.org/understanding-birds/birdfacts/stone-curlew. Accessed 15 May 2024.
"Stone Curlew." The Wildlife Trusts, www.wildlifetrusts.org/wildlife-explorer/birds/wading-birds/stone-curlew. Accessed 15 May 2024.