The Palawan Forest Turtle; under threat from international trade (original) (raw)
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Siebenrockiella leytensis (Taylor 1920) – Palawan Forest Turtle, Philippine Forest Turtle
Conservation Biology of Freshwater Turtles and Tortoises, 2012
The Palawan Forest Turtle (or Philippine Forest Turtle), Siebenrockiella leytensis (Family Geoemydidae), is one of the most enigmatic species of freshwater turtles in Southeast Asia, and has been surrounded with more confusion and misconception than almost any other turtle in the region. For over 80 years, its true geographic distribution in the Philippines remained a mystery; its apparent rarity and the rudimentary knowledge of its ecology and natural history had bestowed upon it an almost mythical reputation. Long thought to come from the eastern Philippine island of Leyte, it was very recently discovered to actually occur in the Palawan region of the western Philippines. The species is the largest and heaviest geoemydid turtle known from the Philippines, attaining a carapace length of more than 300 mm and weighing as much as 3.5 kg. Known clutch size is 1-2, and eggs average 49.6 x 26.5 mm in size and weigh 18-30 g. As predicted by previous workers, the recent discovery of a natural population of S. leytensis on Palawan has already spurred a collecting frenzy among wildlife trappers and traders to supply domestic and international markets for the illegal wildlife trade. In spite of its official protected status in local and international listings, the illegal trade in S. leytensis is rampant and is perceived currently as the greatest threat to the species. This threat is exacerbated by the continuing destruction of the lowland forests of Palawan, the primary habitat of the species. If the current trend of overexploitation continues, it is certain that several subpopulations of S. leytensis will soon collapse. In the face of these threats, wildlife authorities on Palawan must immediately enforce relevant laws and encourage greater coordination among appropriate government agencies that typically work in isolation. Conservation programs need to prioritize efforts that will curb illegal collection of S. leytensis and other threatened species and monitor known populations. Top priority research studies for S. leytensis include population biology, ecology, and in-depth investigation of the dynamics of illegal trade in the species.
We report new observations from natural populations of the critically endangered Philippine forest turtle, Heosemys leytensis. Previously known from two cotypes (reportedly from Leyte Island) that were destroyed during World War II, a lone specimen in a U.S. collection, and a specimen purchased on Palawan Island in the late 1980s, its status in the wild has been uncertain since its discovery. Our recent surveys of Palawan and nearby Dumaran islands have documented natural populations that are under immediate threat due to over-harvesting and loss of habitat. Records of captive animals and interviews with residents from these islands suggest that this species is heavily exploited for food, pet trade, and ornamental fish pond curiosities. There is an urgent need to establish a conservation program to study and protect remaining natural populations.
Status and Distribution of Nonmarine Turtles of the Philippines
Chelonian Conservation and Biology, 2008
We present updated accounts on the status and distribution of all known species of freshwater turtles in the Philippines, including information on taxonomy, natural history, exploitation, and conservation status. Six species of native nonmarine turtles (Dogania subplana, Pelochelys cantorii, Cuora amboinensis, Cyclemys dentata, Heosemys spinosa, and Siebenrockiella leytensis) are recognized from the Philippines, 2 of which are trionychids and 4 are geoemydids. One of these (S. leytensis) is an endemic species. There is some evidence to suggest that Philippine populations of P. cantorii, C. amboinensis, C. dentata, and H. spinosa may warrant further taxonomic study. The fauna also includes 3 introduced species (Pelodiscus sinensis, Trachemys scripta elegans, and Chrysemys picta). Pelodiscus sinensis, D. subplana, C. amboinensis, and S. leytensis feature prominently in the domestic food and pet trade. Preliminary information indicates that these species are also illegally exported to supply international animal markets. The lack of basic information on the natural history of freshwater turtles in the Philippines stands as an obstacle to the implementation of effective conservation and management measures. We recommend that a national program for Philippine freshwater turtles be established to address priorities for research, conservation, and management of this threatened and poorly studied faunal assemblage.
2005
The Philippine forest turtle (Heosemys leytensis) is one of the least-known Asian turtles. Until recently it was only known from a single specimen, the neotype (CAS 60930). The rediscovery of this enigmatic turtle in the wild provides access to fresh genetic material, allowing us to rigorously test its phylogenetic position among Asian pond and wood turtles of the clade Bataguridae for the first time. We sequenced 1174 bp of mitochondrial DNA (cytb) and 1076 bp of nuclear DNA (R35 intron) from a newly acquired specimen of H. leytensis (PNM 8488) and compared our sequences to a previously published genetic survey of batagurids. Our main goal is to determine if H. leytensis is closely related to other species of Heosemys (H. spinosa [type species], H. grandis, H. depressa, and H. annandalii [comb. nov.]). Parsimony and likelihood analyses of mitochondrial and nuclear DNA data strongly support H. leytensis as the sister taxon to the Southeast Asian species Siebenrockiella crassicollis (commonly known as the 'black marsh turtle' or 'smiling terrapin'). The close relationship between H. leytensis and S. crassicollis is a novel hypothesis, although both share an easily recognizable diagnostic feature: vertebrals 2-4 are mushroomshaped or 'ginkgo leaf'-shaped. In order to eliminate two potentially monotypic genera, the genus Siebenrockiella is phylogenetically defined to accommodate the close relationship between S. crassicolis and H. leytensis whereas a new name, Panyaenemys, is defined for the distinct H. leytensis stem lineage.
Journal of Asia-Pacific Biodiversity, 2016
All of the world's seven species of marine turtle are threatened by a multitude of anthropogenic pressures across all stages of their life history. The Calamian Islands, Palawan, Philippines provide important foraging and nesting grounds for four species: green turtles (Chelonia mydas), hawksbill turtles (Eretmochelys imbricata), loggerheads (Caretta caretta), and leatherbacks (Dermochelys coriacea). This work aimed to assess the relative importance of turtle nesting beaches and local threats using a combination of social science and ecological research approaches. Endangered green turtles and critically endangered hawksbills were found to nest in the Calamianes. The most important nesting sites were located on the islands off the west of Busuanga and Culion, particularly Pamalican and Galoc and along the north coast of Coron, particularly Linamodio Island. Opportunistic hunting and egg collection, conducted legally by indigenous communities, is the most significant threat to sea turtles in the area. Sites particularly vulnerable to hunting were found to be Galoc Island, Pamalican Island, and Panlaitan Island. Raising awareness, community engagement, and understanding of socio-cultural drivers of sea turtle exploitation, particularly among indigenous communities, are essential to gain support for any effective conservation program. Additionally, more effective enforcement of laws related to the trade in sea turtle products is required to close the commercial and export markets.
Conservation Biology of Freshwater Turtles and Tortoises, 2012
The diversity of all turtles and tortoises (chelonians) in the world that has existed in modern times (since 1500 AD), and currently generally recognized as distinct by specialists in turtle taxonomy and systematics, consists of approximately 331 species, of which 56 are polytypic, with 121 additional recognized subspecies, or 452 total taxa of modern chelonians. Of these, 9 species plus 2 subspecies, or 11 total taxa, of tortoises and freshwater turtles have become extinct since 1500 AD (see Table 1), leaving us currently with 322 species and 119 additional subspecies, aBsTracT.-This is our 6th annual compilation of an annotated checklist of all recognized and named taxa of the world's modern chelonian fauna, documenting recent changes and controversies in nomenclature, and including all primary synonyms, updated from our previous five checklists (Turtle Taxonomy Working Group 2007b, 2009, 2010, 2011; Rhodin et al. 2008). We continue to provide an updated comprehensive listing of important aspects of taxonomy, names, distribution, and conservation status of all turtles and tortoises of the world. We strive to record the most recent justified taxonomic assignment of terminal taxa in a hierarchical framework, providing annotations, including alternative possible arrangements, for some recently proposed changes. We provide common English names and detailed distributional data for all taxa, listing occurrence by countries and many smaller political or geographic subunits (states or regions), including indications of native, extirpated, and introduced (modern or prehistoric) populations. We also include current published and draft IUCN Red List status determinations for all turtles, as well as CITES listings. The diversity of turtles and tortoises in the world that has existed in modern times (since 1500 AD), and currently generally recognized as distinct and included on this checklist, now consists of 331 species. Of these, 56 are polytypic, representing 121 additional recognized subspecies, or 452 total taxa of modern turtles and tortoises. Of these, 9 species and 2 subspecies, or 11 taxa (2.4%), are extinct. As of the current IUCN 2012 Red List, 134 turtle species (58.8% of 228 species listed, 40.5% of all 331 recognized species) are officially regarded as globally Threatened (Critically Endangered [CR], Endangered [EN], or Vulnerable [VU]). We record additional draft Red List evaluations by the IUCN Tortoise and Freshwater Turtle Specialist Group (TFTSG) of the 103 previously "unevaluated" species, and updated draft re-evaluations of previously listed species, allowing us to evaluate the overall current threat levels for all turtles and tortoises. Of the 331 total species of turtles and tortoises, 101 (30.5%) are CR or EN, 155 (46.8%) are Threatened (CR, EN, or VU), and 164 (49.6%) are Threatened or Extinct. If we provisionally adjust for predicted threat rates of Data Deficient species, then ca. 53% of all turtles are Threatened. If we include Extinct species, and also adjust for Data Deficient species, then ca. 57% of all modern turtles and tortoises are either already Extinct or Threatened. Turtles are among the most endangered of the major groups of vertebrates, surpassing birds, mammals, cartilaginous or bony fishes, and amphibians.
Conservation Biology of Freshwater Turtles and Tortoises, 2011
The diversity of all turtles and tortoises (chelonians) in the world that has existed in modern times (since 1500 AD), and currently generally recognized as distinct by specialists in turtle taxonomy and systematics, consists of approximately 330 species, of which 57 are polytypic, with 125 additional recognized subspecies, or 455 total taxa of modern chelonians. Of these, 8 species plus 2 subspecies, or 10 total taxa, of tortoises and freshwater turtles have become extinct since 1500 AD (see Table 1), leaving us currently with 322 species and 123 additional subspecies, aBsTracT.-This is our fifth annual compilation of an annotated checklist of all recognized and named taxa of the world's modern chelonian fauna, documenting recent changes and controversies in nomenclature, and including all primary synonyms, updated from our previous four checklists (Turtle Taxonomy Working Group 2007b, 2009, 2010; Rhodin et al. 2008). We continue to provide an updated comprehensive listing of important aspects of taxonomy, names, distribution, and conservation status of all turtles and tortoises of the world. We strive to record the most recent justified taxonomic assignment of terminal taxa in a hierarchical framework, providing annotations, including alternative possible arrangements, for some recently proposed changes. We provide common English names and detailed distributional data for all taxa, listing occurrence by countries and many smaller political or geographic subunits (states or regions), including indications of native, extirpated, and introduced (modern or prehistoric) populations. We also include current published and draft IUCN Red List status determinations for all turtles, as well as CITES listings. The diversity of turtles and tortoises in the world that has existed in modern times (since 1500 AD), and currently generally recognized as distinct and included on this checklist, now consists of 330 species. Of these, 57 are polytypic, representing 125 additional recognized subspecies, or 455 total taxa of modern turtles and tortoises. Of these, 8 species and 2 subspecies, or 10 taxa, are extinct. As of the current IUCN 2011 Red List, 134 turtle species (58.8% of 228 species listed, 40.6% of all species) are officially regarded as globally Threatened (Critically Endangered, Endangered, or Vulnerable). We now record additional draft Red List evaluations of the 102 previously "unevaluated" species, and updated draft re-evaluations of previously listed species, allowing us to evaluate the overall current threat levels for all turtles and tortoises. Of the 330 total species of turtles and tortoises, 149 (45.2%) are Threatened, with 98 (29.7%) Critically Endangered or Endangered. If we adjust for predicted threat rates of Data Deficient species, then 52% of all turtles are Threatened. If we include Extinct in the Wild and Extinct species, then 48.0% of all modern turtles and tortoises are recorded as either already extinct or threatened with extinction, with a predicted rate of 55% threatened and extinct. Turtles are among the most endangered of the major groups of vertebrates, surpassing birds, mammals, cartilaginous or bony fishes, and amphibians.