Eskimo Curlew

Numenius borealis

Artwork by John James Audubon
  • SCOLOPACIDAE
  • Snipe, Sandpipers, Phalaropes, and allies
  • Charadriformes
  • Zarapito boreal
  • Courlis esquimaux
Introduction
Before the arrival of European settlers, the Eskimo Curlew was one of the most abundant shorebirds in the Western Hemisphere. By the late 1880s, the Eskimo Curlew had disappeared almost completely. It is now feared extinct. Its plight serves as a tragic example of the devastating potential of human impact upon the environment.
Appearance Description
The smallest of North America's curlews, the Eskimo Curlew is about 14 inches in length, with a wingspan of 27 inches. It probably weighs between 10 and 12 ounces, though exact weights have never been obtained. Its long legs, brownish plumage and long, decurved bill are typical of all curlews. Observers must take great care to eliminate similar species before positively identifying this bird. Of the regularly occurring North American curlews, the Eskimo most closely resembles the fairly common Whimbrel, but is at least one-quarter smaller than this shorebird. The Eskimo Curlew's bill is about a third shorter, and has a less dramatic downward curve. Also, the Eskimo Curlew's head is less boldly striped, and has a less distinctive eye stripe, and its plumage—particularly the cinnamon wing linings—are warmer in tone than the Whimbrel's. The Eskimo Curlew may also be confused with its closest relative, the Little Curlew, a Siberian species which is slightly smaller, and rarely found on North America's west coast.
Range Distribution
A denizen of the far north, the Eskimo Curlew is known to have bred in at least two locations within Canada's northwest territories. A more widespread breeding range, including a vast swath of northern Alaska and a portion of eastern Siberia, is suspected. The Eskimo Curlew also bred on the Arctic tundra. Prior to its decline, it was probably the most common Arctic summer bird. 
Habitat
The Eskimo Curlew utilizes a variety of habitats throughout the year. In spring, it settles mainly on tallgrass prairies from Texas north across the Midwest. Its summer, its Arctic breeding habitat is a vast region of soggy, treeless tundra, nearly inaccessible to humans. This complicates the search for possible remaining populations, which must be done either by air, or on marginally accessible areas. During fall migration, the Eskimo Curlew relies upon the North Atlantic coast, where it was formerly found in great numbers, foraging in marshes, meadows, fields, sand dunes, and tidal areas. From here, the Eskimo Curlew makes its way to its wintering grounds on wide open, flat, wet, grassy areas in Argentina, similar to its Arctic breeding grounds.
Feeding
Historic accounts indicate that the Eskimo Curlew has a varied diet throughout its annual cycle. In spring, large flocks gorged on grasshoppers, crickets, and other prairie insects. During fall migration, the species reportedly relied heavily upon coastal berries, particularly crowberry patches along the Labrador coast. The birds also consumed prey such as insects, crabs, and other aquatic invertebrates.
Reproduction
Breeding, since it occurs within North America's least accessible regions, has rarely been observed closely. The Eskimo Curlew's nest sites were described by early ornithologists as crude shallow scrapes lined with down and other nesting material, similar to nests constructed by other curlews. Historic descriptions of the species' breeding behavior are also consistent with the behavior of related species. Both parents brood and care for the chicks, which are able to follow the parents and find their own food soon after hatching. In most curlew species, parental care decreases quickly once the young birds fledge.
Migration
The annual migration undertaken by the Eskimo Curlew was known to involve a 20,000-mile round trip. After wintering in southern Argentina and Uruguay, Eskimo Curlews began to move slowly north in February or early March. Most birds crossed the formidable Andes, then flew up the Pacific coast of South America, arriving at staging areas along the Gulf Coast and southern Midwest by May. Moving northward across the prairies in huge flocks, they fed heavily on insects such as the now-extinct Rocky Mountain grasshopper. By June, the birds arrived on the northern tundra.
 
Following the relatively short breeding season, Eskimo Curlews moved east to the north Atlantic coast, particularly Labrador, where they gorged on crowberries, crabs, and insects in preparation for the long flight back to South America. Once properly fattened, large flocks of Eskimo Curlews embarked on a nonstop, two- to three-day flight over the Atlantic Ocean. Once out over the ocean, most would not see land again until they arrived, weak and starving, on the northern coasts of South America. Here the Eskimo Curlews gorged once again, then worked their way 2,000 miles further south, to wintering grounds at the end of the continent.
  • Unknown
  • Unknown
  • Endangered
  • Possibly extinct
Population Status Trends
The field notes of early American ornithologists detail the startling decline of the Eskimo Curlew. Inconceivable as it seems that such an abundant species could become scarce within a decade or two, such was the plight of the Eskimo Curlew. In Texas, Kansas, and Canada's Maritime Provinces, the bird was reported in immense flocks during migration throughout the 1870s, but had disappeared almost entirely by the end of the century. Eskimo Curlew sightings became noteworthy. Rare reports of migrants continued throughout the first half of the century. Possibly the first and last photographs of Eskimo Curlews were obtained in Galveston County, Texas, in March 1962. The last confirmed curlew was a single bird, shot in Barbados in 1963. The species was officially listed as endangered in the U.S. in 1967, and in Canada in 1980; it is ranked as a species of global concern on Audubon's WatchList.
Conservation Issues
Unchecked hunting led to the Eskimo Curlew's rapid decline. Once, the Eskimo Curlews arriving on the Great Plains in spring, and on the north Atlantic coast in fall were so abundant were that a hunter could kill dozens of birds with a single shot. The flock would then disperse briefly, before returning to the same spot to be fired upon again, to be sold at east coast markets as "dough birds." 
 
Habitat loss also contributed to the curlews' decline. Beginning in the mid 19th century, the wild tallgrass prairies of America's heartland were rapidly converted to agricultural lands. New crops were planted, and naturally occurring wildfires suppressed. These landscape changes led to the rapid extinction of the Rocky Mountain grasshopper, a primary food source for Eskimo Curlews migrating north across the prairies each spring.
 
The Eskimo Curlew received official protection with the passage of the Migratory Bird Treaty Act of 1918—but by then, there were very few left. Organized efforts to locate remaining Eskimo Curlews began in the 1980s, targeting known breeding grounds, South American non-breeding grounds, and major migratory staging areas. Since the 1960s, there have been several unconfirmed reports of individual and even small flocks of Eskimo Curlews. Should a small population be found, a captive breeding program has been suggested, but any management strategy would be controversial. Should it occur, re-establishment of this hemisphere-crossing species would be among the most remarkable conservation stories in history!
What You Can Do
Find out about actions you can take to benefit other declining birds.
More Information
The Last of the Curlews, Fred Bodsworth's 1955 novel, is an excellent and touching account of the life cycle and plight of the Eskimo Curlew in its waning years.
 
Learn more about this species and other birds through these resources.
Natural History References
Bent, A. C. Life Histories of North American Shorebirds. 1929. U.S. National Museum Bulletin 146.
 
Bodsworth, F. 1954. The Last of the Curlews. Longmans, Green and Co, Ltd, London.
 
Boldenow, M. Eskimo Curlew. 2002. Canadian Biodiversity Project.

Gill, R. E., Jr., P. Canevari, and E. H. Iversen. 1998. Eskimo Curlew (Numenius borealis). In The Birds of North America, No. 347 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
 
Gollop, J.B., T.W. Barry, and E.H. Iversen. 1986. Eskimo curlew a vanishing species? Saskatchewan Natural History Society Special Publication No. 17. Regina, Saskatchewan. Northern Prairie Wildlife Research Center Online.
 
Kaufman, Kenn. 1996. Lives of North American Birds. Houghton Mifflin Company, New York.
Richards, Alan. Shorebirds: A Complete Guide to Their Behavior and Migration. Gallery Books, New York. 1988.
Conservation Status References
Bent, A. C. Life Histories of North American Shorebirds. 1929. U.S. National Museum Bulletin 146.
 
Bodsworth, F. 1954. The Last of the Curlews. Longmans, Green and Co, Ltd, London.
 
Boldenow, M. Eskimo Curlew. 2002. Canadian Biodiversity Project.

Gill, R. E., Jr., P. Canevari, and E. H. Iversen. 1998. Eskimo Curlew (Numenius borealis). In The Birds of North America, No. 347 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
 
Gollop, J.B., T.W. Barry, and E.H. Iversen. 1986. Eskimo curlew a vanishing species? Saskatchewan Natural History Society Special Publication No. 17. Regina, Saskatchewan. Northern Prairie Wildlife Research Center Online.
 
Kaufman, Kenn. 1996. Lives of North American Birds. Houghton Mifflin Company, New York.
Richards, Alan. Shorebirds: A Complete Guide to Their Behavior and Migration. Gallery Books, New York. 1988.