Curlews belong to the genus Numenius, a fascinating group of wading birds known for their distinctive long, slender, and downward-curving bills. These birds are generally characterized by their muted brown plumage, which shows little variation throughout the year, making them well-camouflaged in their often muddy or grassy habitats. Curlews are primarily found in wetlands, coastal mudflats, and open fields, where they use their specialized bills to probe deep into soft soil or sand in search of food. While the term “curlew” is commonly associated with a single species in Europe—the Eurasian Curlew (Numenius arquata)—this genus actually comprises eight recognized species distributed across different parts of the world. These birds play an important ecological role in their habitats and have intrigued ornithologists and birdwatchers alike for centuries.
Scientific Classification
The genus Numenius falls within the family Scolopacidae, which includes a broad group of shorebirds such as sandpipers, snipes, and godwits. The order Charadriiformes, to which curlews belong, also contains gulls, terns, and plovers, making it a diverse group of birds adapted to various aquatic and terrestrial environments. The genus Numenius contains eight recognized species, each with unique characteristics but sharing the hallmark long curved bill and relatively large size for shorebirds. These species include the Eurasian Curlew (Numenius arquata), Long-billed Curlew (Numenius americanus), Far Eastern Curlew (Numenius madagascariensis), Whimbrel (Numenius phaeopus), Little Curlew (Numenius minutus), Bristle-thighed Curlew (Numenius tahitiensis), Eskimo Curlew (Numenius borealis), and the Slender-billed Curlew (Numenius tenuirostris), the latter two critically endangered and possibly extinct.
It is important to distinguish true curlews from the so-called “stone curlews,” which belong to the family Burhinidae within the same order but are only distantly related. True curlews’ close relatives also include the Upland Sandpiper (Bartramia longicauda), which shares some ecological traits but differs markedly in bill structure and leg coloration.
Geographic Range & Distribution
Curlews have a wide but patchy distribution across the globe, with species inhabiting parts of Europe, Asia, Australia, and the Americas. The Eurasian Curlew (Numenius arquata) is the most widespread species, breeding across much of temperate Europe and Asia and wintering in coastal regions of Africa, southern Europe, and South Asia. The Long-billed Curlew (Numenius americanus), the largest of the curlews, breeds across the grasslands of western North America, from southern Canada down through the United States, and migrates to the coasts of Mexico and the southern U.S. for the winter.
The Far Eastern Curlew (Numenius madagascariensis) breeds in northeastern Asia, particularly Siberia and parts of Mongolia, migrating to coastal Australia and Southeast Asia during the non-breeding season. The Whimbrel (Numenius phaeopus), another widespread species, breeds across northern Europe, Asia, and North America and winters along coasts worldwide, including Africa, South America, and Australasia.
Smaller species like the Little Curlew (Numenius minutus) are primarily found in northern Australia during the non-breeding season but breed in Siberian tundra, while the Bristle-thighed Curlew (Numenius tahitiensis) breeds in Alaska and migrates to Pacific islands such as Hawaii and Polynesia. Unfortunately, the Eskimo Curlew (Numenius borealis) and Slender-billed Curlew (Numenius tenuirostris) have drastically reduced ranges due to population declines, with their current status uncertain.
Physical Description
Curlews are among the largest shorebirds, with size and plumage varying slightly between species but sharing a generally similar appearance. They typically measure between 40 and 60 centimeters in length, with wingspans ranging from 70 to 100 centimeters, depending on the species. Weight ranges from approximately 300 grams in the smaller Little Curlew to over 1 kilogram in the Long-billed Curlew, the latter being the largest curlew species.
The most distinctive feature of curlews is their elongated, down-curved bill, which can measure up to 15 centimeters in the Long-billed Curlew. This specialized bill allows them to probe deep into mud and soft soil to extract invertebrates inaccessible to other birds. Their plumage is predominantly shades of brown, streaked and mottled with darker markings that provide effective camouflage in their natural habitats. This coloration remains fairly consistent throughout the year, with only subtle changes between breeding and non-breeding seasons.
Curlews have relatively long legs, adapted for wading in shallow waters and soft mudflats. Their wings are broad and pointed, enabling strong, sustained flight during long migratory journeys. The Whimbrel, for example, has a wingspan of about 80–90 centimeters and weighs around 300–400 grams, making it a medium-sized curlew. The Bristle-thighed Curlew is notable for its shorter but robust legs and a distinctive bristle of feathers on the thighs, which inspired its name.
Behavior & Diet
Curlews exhibit a range of behaviors adapted to their habitats and feeding strategies. They are generally shy, cautious birds that rely heavily on their cryptic plumage to avoid predators. During the breeding season, males perform elaborate aerial displays and calls to attract mates and establish territories.
Feeding primarily occurs in mudflats, marshes, and wet meadows. Curlews use their long bills to probe the mud or soft soil, extracting a diet mainly composed of worms, insect larvae, mollusks, crustaceans, and other invertebrates. Their bills are incredibly sensitive, allowing them to detect prey beneath the surface without sight. In coastal areas, curlews also feed on small crabs, shrimps, and occasionally small fish.
Curlews are mostly diurnal, feeding during the day but sometimes foraging at dusk or dawn. They may also pick food items from the surface or shallow water. Some species are known to behave opportunistically, following plows in agricultural fields to capture insects disturbed by the machinery. Migratory species undertake impressive long-distance flights, often covering thousands of kilometers between breeding and wintering grounds, relying on stopover sites rich in food to refuel.
Breeding & Reproduction
Curlews breed in a variety of open habitats, including moorlands, tundra, grasslands, and coastal marshes, depending on the species. Their breeding season generally coincides with spring and early summer when food availability is highest. Males perform distinctive courtship displays involving vocalizations and flight patterns to attract females and establish territories. According to Cornell Lab of Ornithology, this species is well documented.
Nests are simple scrapes on the ground, sometimes lined with vegetation. The female typically lays between two to four eggs, which are well-camouflaged with speckled brown and tan markings to blend into the surrounding environment. Both parents participate in incubating the eggs, which hatch after approximately 25 to 30 days, depending on the species. According to Audubon Society, this species is well documented.
Chicks are precocial, leaving the nest shortly after hatching and able to feed themselves under parental guidance. They grow rapidly, fledging within 30 to 40 days. Breeding success depends heavily on environmental conditions, predator presence, and human disturbance. In many regions, habitat loss and degradation have contributed to declines in curlew populations, impacting their reproductive success.
Conservation Status
The conservation status of curlews varies significantly between species. The Eurasian Curlew (Numenius arquata), while still relatively widespread, is listed as Near Threatened by the International Union for Conservation of Nature (IUCN) due to ongoing declines caused by habitat loss, agricultural intensification, and disturbance. Populations in the United Kingdom and parts of Europe have seen marked decreases in recent decades.
The Slender-billed Curlew (Numenius tenuirostris) and Eskimo Curlew (Numenius borealis) are both classified as Critically Endangered and possibly extinct. The Slender-billed Curlew, once found across parts of Europe and North Africa, has not been reliably recorded since the late 20th century. The Eskimo Curlew, a North American species, has not been definitively sighted in the wild since the early 2000s, with habitat loss and hunting identified as major factors in their decline.
Other species such as the Far Eastern Curlew (Numenius madagascariensis) are listed as Vulnerable, with threats including wetland drainage, coastal development, and pollution impacting their migratory stopover points and wintering habitats. Conservation efforts focus on habitat protection, research, and international cooperation to safeguard migratory routes and breeding grounds.
Interesting Facts
Curlews are renowned for their distinctive, haunting calls, which have inspired folklore and poetry across cultures. Their name is believed to imitate the curlew’s distinctive “cur-lee” call, a series of rising and falling whistles that can carry over long distances. These vocalizations are particularly prominent during breeding season when males use them to establish territories.
Their long bills are not just striking but functional marvels, equipped with sensitive nerve endings that allow precise detection of prey beneath the surface. This evolutionary adaptation enables curlews to exploit food sources unavailable to many other birds.
One of the most remarkable aspects of curlews is their migratory endurance. The Bristle-thighed Curlew, for example, undertakes a nonstop flight of over 4,000 kilometers from its breeding grounds in Alaska to Pacific islands thousands of kilometers away, demonstrating exceptional stamina and navigation skills.
Curlews also exhibit fascinating nesting behaviors. Some species nest in loose colonies, while others maintain solitary territories. Their chicks are among the most developed at hatching among shorebirds, able to walk and forage almost immediately, which is critical for survival in exposed open habitats.
Despite their widespread presence, curlews are often elusive birds, blending seamlessly into their landscapes. For birdwatchers and wildlife photographers, spotting a curlew offers a rewarding challenge, combining patience with an appreciation for the subtle beauty of these understated but remarkable birds.
In summary, curlews represent a unique group of shorebirds with specialized adaptations that have allowed them to thrive in diverse and often challenging environments. Understanding and protecting these birds requires global awareness and cooperation, given their migratory nature and sensitivity to habitat changes. Through continued research and conservation efforts, the future of curlews can be secured for generations to come.
