Sanderling Plan - Western Hemisphere Shorebird Reserve Network

EXECUTIVE SUMMARY
The Sanderling (Calidris alba) is a small shorebird that breeds in the high arctic and
migrates to temperate, tropical, and south-temperate beaches. In North America, the Sanderling
is classified as a Species of High Concern because of its significant population declines,
widespread habitat loss, and the threats it faces during the nonbreeding seasons (migration and
winter).
The Sanderling has a circumpolar breeding distribution, however there is little
morphological differentiation among breeding populations. In contrast, some differentiation of
individuals occurs on the nonbreeding range. Only one race of Sanderling is recognized. This
species uses three major migration flyways in the Americas: Pacific, Central, and Atlantic.
The largest North American concentrations of Sanderlings occur during spring migration,
where tens of thousands of birds gather on the mid-Atlantic coast (coastal beaches of Delaware
Bay) and at shallow alkaline lakes in the Canadian Prairies (Saskatchewan). Other large spring
concentrations also occur on the central coast of North Carolina (Dinsmore et al. 1998, Walters
1984); on outer coastal sandy beaches of central Oregon, and southern Washington (Myers et al.
1984b, 1984b); and in Alaska (Isleib 1979).
Fall migration in North America is more protracted, extending from mid-July to late
October (or November), with birds being generally less aggregated in space. However, some
Sanderlings aggregate in Massachusetts (up to 17,000 individuals), New Jersey (8,000), Virginia
(several sites with 17,000), Texas (8,400), and Washington (10,000) (International Shorebird
Survey database). Otherwise, Sanderlings spread out during fall, moving through important sites
along the Great Lakes shorelines and all along Pacific and Atlantic coastlines. During winter,
Sanderlings are dispersed, and a pronounced site fidelity in most locations and territoriality by
many individuals likely influence population structure (Myers et al. 1988).
Sanderlings need explicit conservation planning for several reasons:
o Population declines;
o Widespread habitat loss. Their principal habitat is wide-open sandy beaches and barrier
islands, which are threatened by development and chronic human disturbance;
WHSRN – Sanderling Conservation Plan, February 2010, v1.1 1