|
As its name implies, the Long-billed Curlew stands out for its long, decurved bill (curved down) and its large size. In fact this is the largest shorebird in North America. The largest females (males are smaller) can have bills exceeding 200 mm and body masses over 900 g. During the summer, this species breeds in open grasslands, including some agricultural fields (especially in the Great Basin) from central Oregon and north-eastern California east to the mid-western states as well as in the grassland regions of southern British Columbia, Alberta and Saskatchewan. Of the Numeniini, this shorebird has one of the shortest migrations, mainly migrating west and south to wintering areas including interior regions of California, Texas, and Mexico but especially coastal California, Mexico, and Texas. A small number of curlews winter along the coast of southeastern USA.
Long-billed Curlews breed in open grasslands, especially in areas where grass is shorter. They form a cup nest on the ground, that they line with various material, and almost always lay 4-egg nests. The incubation period is 27-29 days, and young are almost immediately mobile. After hatching, chicks are moved to areas of higher grass cover for protection against predators and are brooded by both parents until they are about two weeks old. On breeding grounds, curlews appear to mainly feed on invertebrates like grasshoppers and beetles but will also eat bird eggs and their young.
Relative to other curlews and godwits, these are short distance migrants, sometimes making it from breeding grounds to wintering areas in less than two days. Tend to migrate in flocks of less than 50 birds and there is some suggestion that family units may migrate together. Some birds appear to stage in certain agricultural areas like the Central Valley and Imperial Valley of California, before continuing on to final winter destinations.
In the Pacific region, a significant number of Long-billed Curlews winter in interior valleys of California, while the rest winter along the coast. Along the west coast, the largest concentrations of curlews occur at San Francisco Bay. Coastal birds feed on tidal flats and on beaches, using their long bills to probe for invertebrates like Ghost Shrimp. They are often seen roosting in mixed flocks with Marbled Godwits.
Total population is estimated at 123,500 individuals (Morrison et al. 2007). Under the US Shorebird Conservation Plan (see http://www.fws.gov/shorebirdplan/), they are a species of High Concern mainly due to population declines over parts of their range, their low population size, and threats to their non-breeding and breeding grounds.
Dugger, B. D. and K. M. Dugger. 2002. Long-billed Curlew (Numenius americanus). In The Birds of North America No. 628 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington D. C.: The American Ornithologists' Union.
Text courtesy of PRBO
If you see a marked curlew, please note the date and location of your observation and the color, alpha-numeric code, and position of the bands on the legs of the bird. Any observations can be reported to:
Alex Hartman
University of Nevada-Reno
1000 Valley Road
Reno, NV 89512
Phone: (775) 784-1467
chartman@unr.nevada.edu
website: http://www.unr.nevada.edu/~chartman/sat.html
|
Long-billed Curlew (Numenius americanus)