SREL Reprint #3130

A Global Analysis of Tortoise and Freshwater Turtle Distributions with Identification of Priority Conservation Areas

Kurt A. Buhlmann1, Thomas S. B. Akre2, John B. Iverson3, Deno Karapatakis1,4, Russell A. Mittermeier5, Arthur Georges6, Anders G. J. Rhodin7, Peter Paul van Dijk5, and J. Whitfield Gibbons1

1University of Georgia, Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802 USA
2Department of Biological and Environmental Sciences, Longwood University,
201 High Street, Farmville, VA 23909 USA
3Department of Biology, Earlham College, Richmond, IN 47374 USA
4Savannah River National Laboratory, Savannah River Site, Building 773-42A, Aiken, SC 29802 USA
5Conservation International, 2011 Crystal Drive, Suite 500, Arlington, VA 22202 USA
6Institute for Applied Ecology Research Group, University of Canberra,
Australian Capitol Territory 2601, Canberra, Australia
7Chelonian Research Foundation, 168 Goodrich Street, Lunenburg, MA 01462 USA

Abstract: There are currently ca. 317 recognized species of turtles and tortoises in the world. Of those that have been assessed on the IUCN Red List, 63% are considered threatened, and 10% are critically endangered, with ca. 42% of all known turtle species threatened. Without directed strategic conservation planning, a significant portion of turtle diversity could be lost over the next century. Toward that conservation effort, we compiled museum and literature occurrence records for all of the world’s tortoises and freshwater turtle species to determine their distributions and identify priority regions for conservation. We constructed projected range maps for each species by selecting geographic information system–defined hydrologic unit compartments (HUCs) with verified locality points, and then added HUCs that connected known point localities in the same watershed or physiographic region and that had similar habitats and elevations as the verified HUCs. We analyzed a total of 305 turtle species and assigned each to 1 of 7 geographic regions of the world. Patterns of global turtle species distributions were determined and regional areas of turtle species richness identified. In only 2 areas of the world did as many as 18 or 19 species occur together in individual HUCs. We then compared species distributions with existing global conservation strategies (GCSs) and established biodiversity priority areas. Presence of a species in a GCS was defined as ≥5% its range. Of the 34 biodiversity hotspots, 28 collectively contain the projected ranges of 192 turtle species, with 74 endemic; the 5 high-biodiversity wilderness areas contain 72 species, with 17 endemic; and 16 other wilderness areas contain 52 species, with 1 endemic. However, 116 turtle species have either >50% of their ranges in existing GCSs (57 species) or do not occur in them at all (59 species, 19.3%), thus potentially leaving many tortoises and freshwater turtles without any regional GCS. For each of these 116 species we identify a priority Ecoregion for further conservation consideration, and we identify 3 new global Turtle Priority Areas for conservation based on aggregated Ecoregions. These are the Southeastern United States, Lower Gangetic Plain, and Coastal Australia Turtle Priority Areas.

Keywords: Reptilia; Testudines; tortoise; turtle; distribution; species richness; endemism; conservation; global conservation strategies; biodiversity hotspots; high-biodiversity wilderness areas; Ecoregions

SREL Reprint #3130

Buhlmann, K. A., T. S. B. Akre, J. B. Iverson, D. Karapatakis, R. A. Mittermeier, A. Georges, A. G. J. Rhodin, P. P. van Dijk, and J. W. Gibbons. 2009. A Global Analysis of Tortoise and Freshwater Turtle Distributions with Identification of Priority Conservation Areas. Chelonian Conservation and Biology 8(2): 116-149.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).