Fossil bones collected in the early 1990s from Henderson Island have revealed a new species of Polynesian sandpiper. This extinct little bird is detailed in an article for the Zoological Journal of the Linnean Society.
The newly described bird is officially named Prosobonia sauli after bird watcher and ecologist Edward C. Saul.
A group of researchers from New Zealand, Australia, Denmark, Switzerland, the Netherlands, and China, led by Canterbury Museum curator Vanessa De Pietri, described a new species of sandpiper based on 61 fossilized bones. They are kept in the Natural History Museum in England.
Sandpipers are birds of the order Charadriiformes, which are commonly found along the coastline and muddy shoals, hence they are called wading birds. The term waders is used in most parts of the world.
Canterbury Museum Visiting Fellow Dr. Graham Regg collected bones from caves and ledges on Henderson Island in 1991 and 1992.
Prosobonia sauli is the fifth known species of the Polynesian sandpiper. All species became extinct, except for one endangered Tuamotu sandpiper, Prosobonia parvirostris.
Scientists suggest that Prosobonia sauli probably died out shortly after the arrival of humans on Henderson Island, which, according to archaeologists, did not occur until the 11th century. Perhaps these people brought with them rats, to which the populations of Polynesian waders are very vulnerable.
DNA from the living Tuamotu sandpiper and the extinct Tahitian sandpiper (Prosobonia leucoptera), whose remains are at the Naturalis Biodiversity Center in the Netherlands, have been used to determine the relationship of Polynesian waders to other wading birds.
Comparison with two other extinct Polynesian waders, the Kiritimati wader (Prosobonia cancellata) and the Mo’orea wader (Prosobonia ellisi), was a real test. These birds are known only from illustrations, mainly by William Wade Ellis, artist and assistant surgeon on Captain James Cook’s third expedition, who probably saw the birds alive in the 1770s.
Compared to the Tuamotu wader, its closest relative geographically, the Henderson wader had longer legs and a wider, straighter bill. It is likely adapted to habitats on Henderson Island, which are different from those on other islands where Polynesian waders have been found.
Henderson Island is the largest island in the Pitcairn group, located in the center of the South Pacific Ocean. It has been uninhabited since around the fifteenth century and was listed as a UN World Heritage Site in 1988.
Paul Scofield, senior curator of natural history at the Canterbury Museum and one of the study co-authors, says there are a number of unique species on Henderson Island, some of which are terrestrial birds.
Scientists emphasize that their research demonstrates the need to protect one of the remaining species of Polynesian waders – the Tuamotu wader.