STATUS of the WESTERN POND TURTLE (Clemmys Marmorata) in WASHINGTON
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DEPARTMENT OF WILDLIFE a shing to n---' July 1993 STATUS OF THE WESTERN POND TURTLE (Clemmys marmorata) IN WASHINGTON Washington Department of Wildlife Wildlife Management Division The Washington Department of Wildlife maintains a list of endangered, threatened and sensitive species (Washington Administrative Codes 232-12-014 and 232-12-011, Appendix B). Species are evaluated for listing using a set of procedures developed by a group of citizens, interest groups, and state and federal agencies (Washington Administrative Code 232-12-297, Appendix B). The procedures were adopted by the Washington Wildlife Commission in 1990. They specify how species listing will be initiated, criteria for listing and delisting, public review, and recovery and management of listed species. The first step in the process is to develop a preliminary species status report. The report includes a review of information relevant to the species' status in Washington including, but not limited to: historic, current, and future species population trends, natural history including ecological relationships, historic and current habitat trends, population demographics and their relationship to long term sustainability, and historic and current species management activities. The procedures then provide for a 90-day public review opportunity for interested parties to submit new scientific data relevant to the status report and classification recommendation. During the 90-day review period, the Department holds one public meeting in each of its administrative regions. At the close of the review of the draft report, the Department completes a final status report and listing recommendation for presentation to the Washington Wildlife Commission. The final report, listing recommendation, and any State Environmental Policy Act findings are then released for public review 30 days prior to the Commission presentation. This report is the Department of Wildlife's final Status Report and listing recommendation for the western pond turtle. The listing proposal will be presented to the Washington Wildlife Commission on August 14, 1993 at the Colville Community Center, Colville, Washington. Comments on the report and recommendation may be sent to: Endangered Species Program Manager, Washington Department of Wildlife, 600 Capitol Way N, Olympia, WA 98501-1091; or presented to the Wildlife Commission at its August 14 meeting. This report should be cited as: Washington Department of Wildlife. 1993. Status of the western pond turtle (C/emmys mannorata) in Washington. Unpub!. Rep. Wash. Dept. Wild!., Olympia. T ABLE OF CONTENTS LIST OF TABLES AND FIGURES. v ACKNOWLEDGMENTS ..... .... .. ... .................... VI EXECUTIVE SUMMARY ........ ... ...... .. ...... ...... .. VII TAXONOMY .............................................. 1 DESCRIPTION ................. .... ........ ... ..... .. 1 DISTRIBUTION. .. 2 North America ..... .. ...... ......... ... .. .... .... 2 Washington ...... ........................•........... 2 NATURAL HISTORY ........... .... ......... .. ... .. ... .. ..... 6 Behavioral Characteristics. .. 6 Diet . .. 7 Interspecific Relationships .. ............................... 8 HABITAT REQUIREMENTS ... ..... ........ ...... ......... .... 8 General . .. 8 Substrate and Vegetation ......... ..... ......... ........... 9 Basking Sites ' . 9 Refugia .. ..... .. .. .. .. .................. ... .......... 10 Water Conditions .....•............. .................... 10 Uplands ... .... .... .. .. ... .. .. ...... ........ .. ...... 10 POPULA nON DYNAMICS ...................... .... ... ... .. .. 11 Reproduction ......................... .... ............. 11 Mortality .. .. ......•......... .. ........ ........ ... 12 General .............. ..... ...... .. ............ .. 12 Predation ... .... ................. ........... .. 12 Drought ...... .... .................. ....... 12 Parasi tes . 13 Disease ................................ .... .... 13 Contaminants .. .. ... ........... ..... .. 13 POPULATION STATUS . .. .... ....................... 13 Past ... ....... ... .. .. ... .. ............ .. ... ...... 13 General ........ ....... ............ ..... .. ... 13 July 1993 III Washington Department of Wildlife Puget Sound ....................... .......... ... 14 Columbia Gorge .................................... 15 Present . 17 Future ..... 18 HABITAT STATUS . ... ................... ...... ........ 18 Past . 18 Present ................................... ... ........ 19 Klickitat County .... ... ......... .. .. .......... .. ... 19 Skamania County . ........................ .............. 21 Puget Sound ............. ............................. 21 CONSERVATION STATUS ... .. .. ...... ... ..................... 21 Legal Status ........................................... 21 Management Activities ........ .. ......................... 22 Critical Habitat Acquisition ........... ..... ... ....... 22 Habitat Enhancement. ........ ...... ... .. ... ........ 22 Predator Removal. 22 Surveys ......... ....... ....... ... .. .............. 22 Captive Breeding Program . 23 Head Start Program. ............................ .... 23 FACTORS AFFECTING CONTINUED EXISTENCE ..................... 23 Adequacy of Existing Regulatory Mechanisms ...................... 23 Present and Threatened Habitat Loss ......................... .. 23 Human Disturbance ...................................... 24 Interspecific Relationships ................ ................. 25 CONCLUSIONS AND RECOMMENDATION ...... ... ............... 25 REFERENCES CITED .. .......... ....... ...................... 27 PERSONAL COMMUNICATIONS ................................. 30 Appendix A. Key to sexually dimorphic charac.ters in the western pond turtle ....... 31 Appendix B. Washington Administrative Codes ... ........... ........ 33 July 1993 IV Washington Department of Wildlife LIST OF TABLES AND FIGURES Table I . Western pond turtle specimens collected in Washington 6 Table 2. Results of 1992 western pond turtle surveys in Washington 17 Figure I. Range of the western pond turtle . 3 Figure 2. Range of the western pond turtle in Washington . .. 4 Figure 3. Hypothesized historical distribution of the western pond turtle in the area of Puget Sound . ...................................... 5 Figure 4. Size/age class composition of the western pond turtle population in Klickitat County ...................................... 16 July 1993 v Washington Department of Wildlife ACKNOWLEDGMENTS This status report was compiled by Scott A. Richardson and has been drawn primarily from a Department of Wildlife contract report prepared by Dan C. Holland (I99Ic). It was improved after reviews by Dan Holland, Kate Slavens, and Kelly McAllister. The cover illustration was drawn by Siobhan Sullivan. The Department appreciates the interest shown and information provided by individuals who attended the public meetings or wrote letters concerning the status report and listing proposal. July 1993 VI Wash ington Department of Wildlife TAXONOMY The western pond turtle (Clemmys marmorala) has been known variously as the Pacific pond turtle, western mud turtle, Pacific mud turtle, and Pacific fresh-water turtle. It is a member of the order Testudines and the family Emydidae. The type specimens of the western pond turtle were collected during the U.S. Exploring Expedition in 1841 in the vicinity of Puget Sound, and were described by Baird and Girard (1852) as Emys marmorara. The first use of the combination Clemmys marmorara was by Strauch (1862). Seeliger (1945) divided the species into two subspecies: the northwestern pond turtle (Clemmys marmorara marmorara) and the southwestern pond turtle (Clemmys marmorara pal/ida). The northwestern subspecies is found from the Sacramento Valley, California northward to Puget Sound. The southwestern subspecies is found from the vicinity of Monterey, California southward to Baja California Norte. The area of the San Joaquin Valley, California is considered a zone of intergradation. Seeliger's description of the two subspecies is based upon examination of 158 specimens from throughout the range of the species (Washington and Nevada excluded). Holland (1992) examined 5,137 specimens and distinguished three morphologically distinct forms. One form is restricted to the Columbia River Gorge, while Puget Sound animals are most similar to turtles from the Willamette drainage. DESCRIPTION The western pond turtle is a moderate-siz':d emydid. Maximum size varies geographically, with the largest animals reaching 210 mm (8.2 in). Large anim;lls may exceed I kg (2.2 Ib) in mass. In a series of 45 adults from Klickitat County the mean weight of males was 554 g (1.2 lb) and the mean weight of non-gravid females was 504 g (l.l Ib) (D. Holland, unpubl. data) . Non-gravid females of a given carapace length are usually significantly heavier than males (Holland 1985a). Hatchlings are 25-31 mm (1.0-1.22 in) in length and weigh from 3-7 g (0.11-0.25 oz) (D. Holland and F. Slavens, unpubl. data). The color of this species varies geographically and with age. In general, animals in the northern part of the range are darker in overall coloration. The ground color of the carapace is generally dark brown or black, but may be reddish in a small percentage of the females in a given population. In some extremely old males the melanin in the carapace appears to disappear in a patchy manner, producing a piebald or mottled appearance. The carapace may be unmarked, or may possess a series of fine black radii or lines extending outward