Ecology of a Vulnerable Shorebird across a Gradient of Habitat Alteration: Bristle-Thighed Curlews (Numenius tahitiensis) (Aves: Charadriiformes) on Palmyra Atoll1

Abstract

Abstract: Palmyra Atoll, USA, in the Central Pacific, has remained mostly uninhabited since construction and abandonment of a U.S. naval base during World War II. However, the effects of Navy modifications have persisted, affecting physical conditions and benthic habitat quality of Palmyra's lagoon sand flats. Sand flats provide important nonbreeding habitat for Bristle-thighed Curlews (Numenius tahitiensis), a migratory shorebird listed as “vulnerable” by the International Union for Conservation of Nature and Natural Resources. We used camera trapping, observations of focal individuals, and quantification of prey availability and sediment characteristics to assess curlew habitat use across different levels of historical anthropogenic impact. Habitat preferences were not determined by the degree of land reclamation impact on lagoon flat habitat, although the two most preferred sites were both highly impacted. Curlew abundance was most strongly correlated with availability of prey items, such as spionid po...