Sharp-tailed Sandpiper

Sharp-tailed Sandpiper is an Old World species closely related to our Pectoral Sandpiper (Calidris melanotos). It breeds in the Russian Far East and winters in Australasia. It's considered a fairly common fall migrant in Western Alaska and a rare fall migrant all along the Pacific Coast. According to the various field guides, these coastal strays are almost always juveniles, and all records for Sharp-tailed Sandpiper I can find for Sonoma County (about 10, most at Bodega Bay) appear to be juvenile birds. Sharp-tailed Sandpiper is rare enough in Sonoma County that a sighting creates quite a stir in the local birding community. The bird pictured above, a juvenile, was photographed at Shollenberger Park in October 2011. This bird was first reported there on October 4. It stayed through at least October 15. According to some reports, two were present, but no one to my knowledge photographed two birds together, so that remains unconfirmed. Sharp-tailed Sandpiper has also been recorded in neighboring Marin County, mostly at Abbotts Lagoon.

Sharp-tailed Sandpiper is a medium-sized, fairly stocky sandpiper, about the size of a Dunlin (Calidris alpina). Juveniles are distinguished by a rufous cap with very fine black streaking; a distinct white supercilium, or eyebrow, that may be somewhat thicker and whiter behind the eye; a fine white eyering (although this is subtle and may be hard to see in the field); much rufous in the fringes of the feathers of the upper parts; and a diffusely buffy upper breast with very little streaking. The bill, of moderate length, is mostly black, but paler at the base. Legs are dull greenish, but leg color is variable, and can change deceptively in different lights. Legs may look quite yellow. The white supercilium has the effect of setting off the rufous cap.

Most likely to be confused with the much more common Pectoral Sandpiper. Juvenile Pectoral Sandpiper generally looks washed out by comparison, with less rufous in the cap and breast in particular. The upper breast of juvenile Pectoral Sandpiper is more distinctly streaked and the border between the breast markings and its white underbelly is abrupt, whereas the buffy areas of Sharp-tailed Sandpiper's breast fade into its paler underparts. Sharp-tailed Sandpiper often has dark streaks under the tail (visible in the photo above), lacking in Pectoral Sandpiper. In Pectoral Sandpiper, there is usually more pale coloration at the base of the bill than in Sharp-tailed Sandpiper. Legs of Pectoral Sandpiper are usually paler and more yellow, but leg color is variable. Sharp-tailed Sandpiper shows less sexual size dimorphism than Pectoral (the male Pectoral Sandpiper is noticeably bigger than the female).

In breeding plumage, Sharp-tailed Sandpiper will again have more rufous in the cap and on the back than Pectoral Sandpiper, and in breeding plumage Sharp-tailed Sandpiper acquires chevron-shaped dark markings all along the flanks that extend under the tail. In contrast, streaking stops abruptly at the lower breast in Pectoral Sandpiper in all plumages. Keep in mind, however, that most Sonoma County sightings of Pectoral Sandpiper will be juveniles and, to my knowledge, no adult Sharp-tailed Sandpiper has ever been observed in the county.

Selected county sightings: Bodega Bay (September 21-23, 2012); Shollenberger Park (October 4-15, 2011), Shollenberger Park (November 07, 2006); Hudeman Slough Wetlands Enhancement Area (November 7, 2004); Doran Regional Park Mudflats (September 23, 2001); Doran Regional Park Mudflats (October 6-7, 2001)--the previous four sightings from Parmeter and Wight; Doran Regional Park, Bodega Bay (September 15, 1996--this and older sightings are from Birds of Sonoma County); Spud Point, Bodega Bay (November 8, 1995), Doran Regional Park, Bodega Bay (November 5-8, 1995), Doran Regional Park, Bodega Bay (October 24-27, 1992). Bolander and Parmeter also note sightings in 1983, 1979, and 1969 (two different dates in 1969).