Introduction

Among North American shorebirds, the Black Turnstone is synonymous with the rocky, wave-washed Pacific Coast. Here the zebralike color and pattern of its plumage make it all but invisible while foraging and roosting on dark rocky substrates or when flying through the splash and spray of breaking waves. Its English name refers to its habit of flipping over objects to get at foods either beneath or attached to stones, algae, hard-shelled invertebrates, and all sorts of supratidal jetsam. When feeding in the wave zone it uses its specialized bill for prying loose or chiseling apart sessile foods, particularly mussels and barnacles.

The Black Turnstone is strictly a bird of western North America and during its annual cycle is seldom found away from areas of marine influence. It breeds in a narrow band of coastal sedge meadows throughout western Alaska where, on places like the central Yukon-Kuskokwim Delta, it could be described as colonial. Its breeding behavior is characterized by an elaborate series of ground and aerial displays with accompanying vocalizations. This turnstone appears to be the self-appointed sentinel of its nesting community. It shrieks warnings of avian predators and relentlessly pursues them, occasionally making contact and even pulling out feathers. In the absence of rocky substrates on the breeding grounds, it resorts to turning and flipping vegetation and driftwood in search of food, a behavior for which, during these 2–3 months of the year, it is more aptly called a “turnstick.”

The species vacates breeding grounds in early summer and moves rapidly to nonbreeding areas that extend from Kodiak I., AK, to the Gulf of California. Here, the reefs, headlands, and sea stacks of the outer coast are its home, one it regularly shares with Surfbirds (Aphriza virgata). During low tide this turnstone’s presence in these cryptic habitats is often betrayed only by its raucous, scolding vocalizations. Beginning in April most individuals are on the move north, stopping briefly in Prince William Sound, AK, before proceeding to the nesting grounds, where most arrive during early May.

For such a relatively common species, many aspects of its biology went unknown until relatively late in the twentieth century. Recent studies provide a reasonably good outline of its population size, distribution, and reproductive ecology (Handel 1982; Handel and Gill 1992, 2000) and its feeding ecology (Connors 1977; Marsh 1984, 1986; Bishop and Green 1999). Lacking is information on its population trend and demographics, and on its behavioral ecology and intra-seasonal movements during the nonbreeding period.