Fossil bones collected in the early 1990s on Henderson Island, which are part of the Pitcairn Collection, revealed a new species of Polynesian sandbird.
Henderson Sandpiper, a small water wading bird that went extinct for centuries, is described in an article in Journal of Zoology of the Linian Society Posted last week.
The newly described bird was officially named Prosobonia sauli after Cook Islands ornithologist and conservationist Edward K.
A team of researchers from New Zealand, Australia, Denmark, Switzerland, the Netherlands and China, led by Canterbury Museum Research Curator, Dr. England.
Canterbury Museum visiting scholar Dr. Graham Wrage collected bones from the overhanging caves on Henderson Island in 1991 and 1992 during Sir Peter Scott’s memorial trip to the Pitcairn Islands.
Prosobonia sauli is the fifth known species of Polynesian sandbird. All species, except for one, are the endangered Tuamotu Sandpiper (Prosobonia parvirostris).
“We think that Prosobonia sauli may have become extinct shortly after the arrival of humans on Henderson Island, which archaeologists estimate occurred before the eleventh century,” says Dr. de Petrie.
“It is possible that these humans brought with them the Polynesian rat, which the Polynesian sandbird populations are extremely vulnerable to.”
Animal DNA Tuamotu Sandpiper live and Tahiti Sandpiper (Prosobonia leucoptera), known only from the skin at the Naturalis Biodiversity Center in the Netherlands, were used to determine how Polynesian sandbirds were related to other wading birds.
“We found that Polynesian sandbirds are divergent early members of a group that includes the sand calidrin and the spinning stone.” They differ from other sandbirds in that they are confined to the Pacific islands and do not migrate, “says Dr.
Comparisons with the other two extinct Polynesian sand species, Kiritimati Sandpiper (Prosobonia cancellata) and Mo’orea Sandpiper (Prosobonia ellisi), are complex. These birds are known only from illustrations by William Wade Ellis, an artist and fellow surgeon on Captain James Cook’s third expedition, who may have seen the birds alive in the 1870s.
Compared to Tuamotu Sandpiper, its geographically closest cousin, the Henderson Sandpiper had longer legs and a wider, straighter beak, indicating how it foraged for food. It may have adapted to the habitats available on Henderson Island, which differs from those on other islands where Polynesian sandbirds are found.
Henderson Island is the largest island in the Pitcairn Group, in the central South Pacific Ocean. It has been uninhabited since around the fifteenth century and was designated a World Heritage Site by the United Nations in 1988.
Dr. Paul Schofield, chief curator of the Canterbury Museum of Natural History and one of the study’s co-authors, says Henderson Island is home to a number of unique species, including a handful of wild birds such as Henderson Sandpiper.
“The island is really wonderful because every type of wild bird that lives there, or that we know used to live there, is not found anywhere else,” he says.
Dr. De Petri says the study shows the need to protect one remaining Polynesian sandbird species, the Tuamotu Sandpiper.
“We know that just a few centuries ago there were at least five Polynesian sand plant species scattered around the Pacific Ocean. Now there is only one, and its numbers are diminishing, so we need to ensure that the rest of the population is taken care of.”
This research was supported by a grant from the Marsden Fund Board, administered by the Royal Society of Te Aprangi, as well as the RS Alan Fund administered by the Canterbury Museum.