| Tahiti sandpiper | |
|---|---|
 | |
| Forster's drawing, 1772–75 | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Charadriiformes |
| Family: | Scolopacidae |
| Genus: | Prosobonia |
| Species: | †P. leucoptera |
| Binomial name | |
| †Prosobonia leucoptera (Gmelin, JF, 1789) | |
| Synonyms | |
Tringa leucopteraGmelin, 1789 | |
TheTahiti sandpiper orTahitian sandpiper (Prosobonia leucoptera) is anextinct member of the largewader familyScolopacidae that wasendemic toTahiti inFrench Polynesia until its extinction sometime before 1819.[2]
It was discovered in 1773 duringCaptain Cook's second voyage, when a single specimen seems to have been collected, but it became extinct in the nineteenth century. Only one museum specimen is known to exist, held in theAves collection ofNaturalis Biodiversity Center. The bird's name in theTahitian language was transcribed astoromē.
The Tahiti sandpiper wasformally described in 1789 by the German naturalistJohann Friedrich Gmelin in his revised and expanded edition ofCarl Linnaeus'sSystema Naturae. He placed it with the other sandpipers in thegenusTringa and coined thebinomial nameTringa leucoptera.[3] Gmelin based his description on the "white-winged sandpiper" that had been described and illustrated in 1785 by the English ornithologistJohn Latham from a specimen collected in Tahiti.[4] The species is now placed in the genusProsobonia that was introduced in 1850 by the French naturalistCharles Lucien Bonaparte with the Tahiti sandpiper as thetype species.[5][6] Bonaparte did not explain the etymology of the genus name, but it is likely from theAncient Greekprosōpon meaning "mask" or "face". The specific epithetleucoptera is derived from Ancient Greekleukopteros meaning "white-winged".[7]
Based on Zusi & Jehl (1970):[8] A small (some 18 cm long), plain-colored sandpiper, brown below, darker above, with a white wing patch. Top and sides of head and neck to wings and back sooty brown, darker on back and wings. A small white patch behind and above the eye. Chin buffish white. Lores, rump and undersiderusty. Wing coverts with some rusty edging.Remiges with paler inner surfaces. Underside of wing dusky brown with paler edges to coverts. A crescent-shaped white patch formed by tertiary coverts; smaller on the underside of the wing. Ten primaries, twelverectrices. Central tail feathers sooty brown with rusty tips; outer ones rusty with sooty brown barring.
Bill blackish, lowermandible slightly paler, pointed, thin and short, rather like in aninsectivorouspasserine than a wader. Legs greenish-hued pale straw color. Toes unwebbed. A slim pale rusty ring around the eye.Iris a very dark brown.
Two probable specimens taken onMoorea byWilliam Anderson between September 30 and October 11, 1777, formed the basis for the description of theMoorea Sandpiper. Three specimens mentioned byJohn Latham in 1787 all differed from one another, but the single remaining one,RMNH 87556, cannot be positively identified with any of them. How it came into the possession of the museum cannot be retraced with complete certainty, but it probably was acquired in 1819 with other specimens fromGeorg Forster.[2] There also exists a painting by Forster, drawn from the original specimen.
At any rate, the specimen agrees better with the Tahiti bird in Forster's painting. The Moorea Sandpiper—of which another painting, by William Ellis, and a plate by John Webber, supposed to depict the other specimen, constitute all remaining evidence—differs in the color of wings and head. Whether these two forms were species, subspecies, or simply variants due to age or sex cannot be determined with certainty, but for the present they are more often treated as different species than not. The Tahiti and Moorea Sandpipers are believed to have occurred near small streams.
Bones of a related form have been found onMangaia in theCook Islands. It is not likely that they will be studied anytime soon; a scientific description would require either successful extraction and analysis ofDNA from both the bones and the Leiden specimen (which would risk being damaged during extraction of the tissue sample), or the collection of a sufficient amount of material from Tahiti or Moorea to determine the Mangaia bird's affiliation by analysis of theosteology.
