Figure 227. The Semipalmated Sandpiper has proved to be an uncommon to rare spring and fall migrant through California. Most fall records involve first-year birds—like this one at the mouth of the Santa Clara River, Ventura County, 4 September 1979—associating with Western Sandpipers (1980-036; Larry Sansone). This image was originally published as being of a Red-necked Stint (NAB 33:214); see WB 6:138–139.

 

 

 

 

 

 

SEMIPALMATED SANDPIPER Calidris pusilla (Linnaeus, 1766)

Accepted: 62 (85%)	Treated in Appendix H: no
Not accepted: 11	CBRC review: records from 1966 through 19801
Not submitted/reviewed: NA	Large color image :see Figure

This small Calidris sandpiper breeds across the nearctic from western Alaska eastward to northern Labrador. Wintering takes place in coastal areas in and around the Caribbean southward to southern Brazil, and along the Pacific coast from southern Mexico to northern Chile. Migration occurs mainly east of the Rocky Mts. In fall, moderate numbers migrate along the Pacific coast southward to the northern coast of Washington, but most move inland from there. The species is a rare, regular fall transient from central Washington south through the Baja California Peninsula. Extralimital records extend to Hawaii, the Galapagos Islands, western Europe, and the Azores.

California’s first recorded Semipalmated Sandpiper was a sick adult in alternate plumage collected on 7 May 1960 near Niland in Imperial County (Cardiff 1961, SBCM 33032). By the late 1970s, careful scrutiny of flocks of small Calidris sandpipers, coupled with an increased understanding of the intricacies of their identification, showed this species to be a rare, regular migrant through the state, an observation supported by some 20 specimens. In California, Semipalmated Sandpipers are typically found among flocks of migrating Western Sandpipers, particularly during the fall passage. Records of 31 individuals were accepted in 1980, the final year of CBRC review.

Semipalmated Sandpipers occur more frequently in fall than in spring across California, except at the Salton Sea, where they are regular in spring (see below) and casual in fall (Patten et al. 2003). Adults known or presumed to be fall migrants occur mainly between 22 June and 31 July, and are found regularly only in the northern half of the state. Monterey County, which averages three or four records per fall, claims no more than three records of fall adults (Roberson 2002, D. Roberson in litt.). The status is comparable in San Diego County, where records average about four per fall and the first adult is yet to be found (Unitt 2004). First-fall birds—most of which pass through between late July and late August—greatly outnumber adults throughout the state. Records trail off through the month of September, and later migrants—such as those found in northern Santa Barbara County on 19 October 1980 and 30 October 1986 (Lehman 1994)—should be identified with particular care and thoroughly documented.

Spring records of alternate-plumaged birds, most of them in May, average about one per year in the northern half of the state (M. M. Rogers in litt.). Most of southern California’s spring records come from the Salton Sea, where one to three individuals turn up during a typical season (21 April–6 June; Patten et al. 2003). An earlier record is from Mystic Lake, Riverside County, 18 April 1988 (SBCM 30647).

Two aseasonal records of adults involve some combination of late or early transients, or perhaps non-breeding summer wanderers: 16–17 June 1976 at Abbotts Lagoon, Marin County, and 12 June 1994 at the mouth of the Salinas River, Monterey County (Roberson 2002).

¹On the review list 1972–1980