Semipalmated Plover (Charadrius semipalmatus)

By Andrew McCormick

The Semipalmated Plover is one of the most common plovers in North America and will attract attention in a flock of shorebirds when it repeatedly runs and stops while foraging for marine worms, crustaceans and small mollusks (Kaufman). It takes a particular stance when stopped. Paulson describes its "'foot-stir,' with one foot extended forward at about 45 degrees and vibrated on the substrate, presumably causing some invertebrates in their visual field to move and be detected." The Semipalmated is most often seen along Washington's coast during spring and fall migration but some have bred in the state.

Along with other North American ringed plovers: Common Ringed, Snowy, Wilson's, Piping and Mountain Plovers and the Killdeer, the Semipalmated Plover is included in the genus Charadius from the Greek kharadra , ravine or cleft, where some shorebirds may have lived. Most of these birds have a white neck collar and one or two dark breast bands, some of which are partial bands. Both the Semipalmated and its Eurasian relative the Common Ringed Plover (C. hiaticula) have two partially webbed toes which gives our species its name semipalmatus , half palmed, from Latin semi , half and palma , the palm (Holloway).

The Semipalmated Plover is a small, stout bird with a rounded head and no neck. It is medium, dark brown on the head and back with black crown bar and facial markings. A white collar extends around the neck and there is a single black breast band. The eye is dark and set off by a narrow yellow eye ring. The legs are orange and the bill is black with an orange base. It is nearly identical to the Common Ringed Plover and some research indicates they may be one species (Nol & Blanken). The Common Ringed would be rarely seen in Washington. The Wilson's Plover has pale legs, and the Snowy and Piping Plovers are much paler on the head and back. Simply put in the Pacific Northwest, "A small brown plover with a single breast band will be this species" (Paulson).

In spring this plover migrates from mid April to mid May and nests in the sub-arctic along sand dunes and sandy and gravel shorelines. The nest is a scrape in the gravel sometimes lined with leaves. Generally four olive-buff to olive-brown eggs blotched with black or brown are deposited. Both parents incubate for about 24 days and both feed the young.  First flight occurs in another 3-4 weeks (Kaufman). Fall migration is heaviest in August but it can be seen into September. It winters along the Atlantic and Pacific coasts of North, Central and South America. It is one of our birds with the longest migration route.

The Semipalmated is a strong and fast flyer and has been timed at 52km/hr (34mph). It also displays using a butterfly-type flight around the nesting area. Its call is a distinctive, upslurred chu-weet , with the second syllable higher pitched and emphatic (Alderfer).

An video and audio recording of the Semipalmated Plover running, calling and in a close-up view can be seen at the Macauley Library of the Cornell Lab of Ornithology at http://macaulaylibrary.org/video/flashPlayer.do?id=12625

Photo credit Gary Luhm. References available upon request from amccormick@eastsideaudubon.org