Remains of Land Birds from Lisianski Island, with Observations on the Terrestrial Avifauna of the Northwestern Hawaiian Islands

摘要

Early nineteenth-century accounts suggest that there were ducksand rails on Lisianski Island, although neither were present in 1891 when thefirst ornithological collector visited the island. Excavations and surface searcheson the island in 1990 uncovered numerous bones of the Laysan Duck (Anaslaysanensis Rothschild), indicating that there once was a resident population.A single coracoid of a small rail (Porzana) probably came from one of the 45individuals of Laysan Rail (P. palmeri Frohawk) that were introduced in 1913and quickly died out, because no further evidence of rails or other land birdswas found. Extinction of the duck may have been due to predation by survivorsof mid-nineteenth-century shipwrecks and possibly to competition for foodfrom introduced House Mice (Mus musculus Linnaeus). The land birds of theNorthwestern Hawaiian Islands were derived partly from Asia and partly fromspecies that were formerly widespread in the lowlands of the main HawaiianIslands. They are not, therefore, a collection of ancient relicts of a montanebiota as has been hypothesized. The terrestrial avifauna of Nihoa isdepauperate even for an island of its size and may have suffered prehistorichuman-caused extinctions.