Freshwater turtles of the Kikori Drainage, Papua New Guinea, with special reference to the pig-nosed turtle, Carettochelys insculpta

Abstract

A survey of the Kikori River drainage of the Gulf Province of Papua New Guinea identified four species of freshwater turtle. The pig-nosed turtle Carettochelys insculpta and the southern New Guinea soft-shelled turtle Pelochelys bibroni are riverine species. The New Guinea spotted turtle Elseya novaeguineae lives primarily in the tidal freshwater creeks and streams, flooded sinkholes and swamps of the lowland rainforest. The New Guinea painted turtle Emydura subglobosa resides almost exclusively in forest sinkholes and swamps. Pelochelys bibroni was the least-common species, and is probably locally endangered. Greatest turtle diversity occurred in the Karst Plains of the Kikori sub-basin, where there is a greater diversity of habitat available to turtles. Lowest diversity occurred in the highlands, where turtles were present in very low density as introduced populations, brought in from the Kikori lowlands, Mount Bosavi and the Western Province by visiting relatives. Linguistic diversity concurred with turtle diversity of the regions in which the languages were spoken. C. insculpta nests both on riverine sand beaches and on coastal beaches, sand spits and isolated sand bars where the Kikori River discharges into the Gulf of Papua. Adult females and eggs of C. insculpta are harvested heavily by local people for local consumption.

Salinity of the coastal nesting environment and its association with body size in the estuarine pig‐nosed turtle

“…These two areas are divided by a delta, embedded in a large alluvial plain formed principally by soft silts and clays deposited over the underlying limestone plain (Enesar Consulting, ). Carettochelys insculpta does not nest in the delta clay banks (Georges et al ., 2008 a ). The riverine area occupies the central part of the Kikori basin, and it is highly confined within its limestone bed.…”

“…Primarily a freshwater group, many species of softshell turtles (Trionychidae) nest and occupy estuarine or even marine habitats (Pritchard, ). Its sister family, Carettochelyidae, comprises one single living species, the pig‐nosed turtle Carettochelys insculpta , which also occurs and nests in coastal areas of southern New Guinea (Rhodin & Rhodin, ; Georges et al ., 2008 a , b ). Female C. insculpta nest in large numbers on coastal beaches and isolated sandbanks of the Gulf of Papua, at the mouth of the Fly, Kikori, Omati and Purari Rivers (Pernetta & Burgin, ; Georges, Guarino & Bito, ; Georges et al ., 2008 a , b ).…”

“…Its sister family, Carettochelyidae, comprises one single living species, the pig‐nosed turtle Carettochelys insculpta , which also occurs and nests in coastal areas of southern New Guinea (Rhodin & Rhodin, ; Georges et al ., 2008 a , b ). Female C. insculpta nest in large numbers on coastal beaches and isolated sandbanks of the Gulf of Papua, at the mouth of the Fly, Kikori, Omati and Purari Rivers (Pernetta & Burgin, ; Georges, Guarino & Bito, ; Georges et al ., 2008 a , b ). However, coastal nesting does not occur in Northern Australia, where populations are restricted to the upper parts of the rivers (Georges & Kennett, ; Doody, Georges & Young, 2003 a ; Doody, Sims & Georges, 2003 b ; Doody, West & Georges, 2003 c ; Georges et al ., 2008 b ).…”

Carettochelys insculpta Ramsay 1886 – Pig-Nosed Turtle, Fly River Turtle

“…In Indigenous Harvest. -Carettochelys insculpta is highly prized as a food item by the indigenous peoples within its range both in Australia and New Guinea (Schultze-Westrum 1963;Cann 1980;Press 1986;Georges et al 2007a and is important to the subsistence economies of several Papuan communities (Pernetta and Burgin 1980). Both the adults and their eggs are collected, consumed, and sold throughout its range in Papua New Guinea.…”

“…In entering partnerships with NGOs such as the World Wide Fund for Nature and universities to mitigate these potential impacts, the company and its joint venture partners are breaking new ground. A three-year project on Carettochelys is part of the current portfolio of environmental initiatives funded or otherwise supported by Oil Search and its joint venture partners (Georges et al 2007a;.…”