Further information on the avifauna of St. Matthew and Hall Islands, Bering Sea, Alaska

In June and July 2018 and July 2019 we surveyed birds on St. Matthew and Hall islands, isolated in the central Bering Sea. Our surveys were focused on the McKay’s Bunting (Plectrophenax hyperboreus), Rock Sandpiper (Calidris ptilocnemis ptilocnemis), and Pelagic Cormorant (Phalacrocorax pelagicus) but encompassed all birds and yielded 13 species and four subspecies new to the islands’ avifaunal list, and new details and documentation of breeding for eight species. Especially notable discoveries include a mixed pair of Bewick’s (Cygnus columbianus bewickii) and Whistling (C. c. columbianus) Swans, a mixed pair of the Glaucous-winged (Larus glaucescens) and an Asian subspecies of the Herring Gull (L. argentatus vegae), and discovery of a colony of ~100 pairs of the Red-legged Kittiwake (Rissa brevirostris). Also, contrary to many previous expeditions, we found the Gray-crowned Rosy-Finch (Leucosticte tephrocotis umbrina) to be common and conclude that it may be resident.