Wednesday, January 9, 2013

Pectoral Sandpiper

Like Least Sandpipers, Pectoral Sandpipers have yellowish legs. But Pectorals are much larger shorebirds than Leasts and are not as dark-backed. Identification, however, could be muddled by the large size difference between male and female Pectorals. Males are almost 30% larger than females. The sharp line of demarcation between the dark breast and white belly is is an excellent field mark.

Pectoral Sandpipers breed across the central and western Canadian Arctic tundra all the way into Siberia. They winter in southern South America, the Siberian populations migrating east or across the Great Circle route over the Arctic Ocean to the New World. These later routes result in distances of over 30,000 km, among the longest for any avian migrant. For her dissertation, Erika studied the trematode parasites of Pectoral Sandpipers as these shorebirds made their intercontinental migrations.

Male Pectoral Sandpipers are either polygynous or promiscuous. In any case, males court any female that lands within his territory and males often leave nesting areas before the young hatch. Males associate with females only long enough for courtship and copulation.

Pectoral Sandpipers are relatively common, but numbers are greatly reduced from the late 1800s, when they occurred in “enormous” numbers. Although this shorebird suffered from intense market hunting, habitat loss may also contribute to their decline. Much of the information in this post was gleaned from Holmes and Pitelka (1998).

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