The largest North American shorebird and one of only 9 species of grassland birds considered endemic to the Great Plains, the Long-billed Curlew has the southernmost breeding distribution and northernmost wintering distribution of the 4 curlew species found in North America. Like other curlews, this one has a ringing call, the familiar “curlew” upon which the name is based. This is a quintessential spring and summer sound of short and mixed grassland habitats throughout midwestern and western portions of the continent. The name Numenius was given to curlews because their long, curved bill was likened to the new crescent moon, the Greek noumenios meaning “of the new moon.” Although the Long-billed Curlew's diet includes many species of invertebrates and some vertebrates, its bill is best adapted for capturing shrimp and crabs living in deep burrows on tidal mudflats (its wintering grounds) or burrowing earthworms in pastures.
The biology of this species is very similar to that of the Eurasian Curlew (N. arquata), a closely related species found across Eurasia but only a vagrant to North America. In both these curlews, pair formation on the breeding grounds is highlighted by a conspicuous aerial display. Both sexes incubate, and both are aggressive in defense of nests and young. The female typically abandons the brood 2–3 weeks after hatching and leaves brood care to her mate. Mate fidelity in subsequent breeding seasons is often high. Individuals are particularly sensitive to human disturbance during the nesting period.
Long-billed Curlew populations have declined significantly during the past 150 years, particularly on the East Coast, where the species was once common during migration but now is rare. Overharvest in migration areas (1850–1917) and elimination of breeding habitat, particularly in the eastern half of the species' historic range, are believed responsible for these declines. There is no accurate estimate of the current population size, but the species is considered vulnerable throughout its range. Continued loss of grassland breeding habitats is thought to be the greatest threat to population stability.
While many aspects of Long-billed Curlew biology remain unknown, work in the Great Basin has been instrumental in understanding breeding-habitat needs, population demography, behavior, and the influence of grazing on habitat suitability (Allen 1980b, Jenni et al. 1981, Redmond and Jenni 1986, Cochrane and Anderson 1987, Pampush and Anthony 1993). On winter areas, recent work in California on both the coast and in the Central Valley has made important contributions to understanding feeding ecology (Boland 1988, Leeman 2000, Leeman et al. 2001), nonbreeding habitat requirements (Elphick and Oring 1998, Elphick 2000, Mathis 2000), and social organization (Colwell and Mathis 2001). All should prove useful in efforts to manage the species.