WASHINGTON STATE STATUS REPORT FOR THE July 1997 Oregon Spotted Frog byby KellyKelly R.R. McAllisterMcAllister andand WilliamWilliam P.P. LeonardLeonard Washington Department of FISH AND WILDLIFE Wildlife Management Program The Washington Department of Fish and Wildlife maintains a list of endangered, threatened and sensitive species (Washington Administrative Codes 232-12-014 and 232-12-011, Appendix). In 1990, the Washington Fish and Wildlife Commission adopted listing procedures developed by a group of citizens, interest groups, and state and federal agencies (Washington Administrative Code 232-12-297, Appendix). The procedures include 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 and addresses factors affecting its status 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, classification recommendation, and any State Environmental Policy Act findings. During the 90-day review period, the Department holds one public meeting in each of its administrative regions. At the close of the comment period, the Department completes the Final Status Report and Listing Recommendation for presentation to the Washington Fish and Wildlife Commission. The Final Report and Recommendation are then released 30 days prior to the Commission presentation for public review. This is a Final Status Report for the Oregon spotted frog. Submit written comments on this report by August 3, 1997 to: Endangered Species Program Manager, Washington Department of Fish and Wildlife, 600 Capitol Way N, Olympia, WA 98501-1091. The Department will present the results of this status review to the Fish and Wildlife Commission for action at the August 8-9 meeting in Richland, Washington. This report should be cited as: McAllister, K. R. and W. P. Leonard. 1997. Washington State status report for the Oregon Spotted Frog. Wash. Dept. Fish and Wildl., Olympia. 38 pp. Washington State Status Report for the Oregon Spotted Frog Washington Department of Fish and Wildlife Wildlife Management Program 600 Capitol Way N Olympia, Washington 98501-1091 Prepared by Kelly R. McAllister and William P. Leonard July 1997 TABLE OF CONTENTS LIST OF TABLES AND FIGURES .............................................v ACKNOWLEDGMENTS .................................................... vi EXECUTIVE SUMMARY ...................................................vii TAXONOMY .............................................................1 DESCRIPTION ............................................................1 Similar Species ........................................................2 GEOGRAPHICAL DISTRIBUTION ............................................7 North America ........................................................7 Washington ..........................................................7 NATURAL HISTORY .......................................................8 Reproduction .........................................................8 Mortality ...........................................................11 Behavioral Characteristics ..............................................12 Mating behavior ................................................12 Foraging ......................................................13 Escape .......................................................13 Interspecific Relationships ..............................................13 Food ..............................................................15 HABITAT REQUIREMENTS ................................................16 General ............................................................16 Food ..............................................................17 Breeding Habitat .....................................................17 Seasonal Habitat .....................................................17 POPULATION STATUS ....................................................18 Past ...............................................................18 Present .............................................................20 Future .............................................................21 HABITAT STATUS ........................................................21 Past ...............................................................21 Present .............................................................22 July 1997 iii Washington Department of Fish and Wildlife Future .............................................................23 CONSERVATION STATUS .................................................23 Legal Status .........................................................23 Management Activities .................................................24 FACTORS AFFECTING CONTINUED EXISTENCE ..............................24 Adequacy of Existing Regulatory Mechanisms ...............................25 Present and Threatened Habitat Loss ......................................25 Other Natural and Manmade Factors ......................................25 CONCLUSIONS AND RECOMMENDATION ...................................26 REFERENCES CITED ......................................................27 PERSONAL COMMUNICATIONS ............................................31 Appendix Washington Administrative Codes ........................................32 July 1997 iv Washington Department of Fish and Wildlife LIST OF TABLES AND FIGURES Table 1. Characteristics of Oregon spotted frog oviposition ..........................10 Table 2. Oregon spotted frog localities in Washington based on museum records ..........19 Figure 1. Comparison of Oregon spotted frog and red-legged frog. ......................2 Figure 2. Comparison of Oregon spotted frog and red-legged frog - groin mottling. .........3 Figure 3. Comparison of Oregon spotted frog and red-legged frog - eye angle. .............4 Figure 4. Comparison of Oregon spotted frog and red-legged frog - webbing. ..............5 Figure 5. Range of the Oregon spotted frog. .......................................7 Figure 6. Locations of populations of the Oregon spotted frog in Washington ..............7 Figure 7. A comparison of oviposition chronology, 1995 - 1997 ........................9 Figure 8. Locations of Oregon spotted frog populations known prior to 1990 .............18 July 1997 v Washington Department of Fish and Wildlife ACKNOWLEDGMENTS Dr. Marc Hayes provided a thorough and thoughtful review of an earlier draft of this report and provided considerable unpublished data, some of which we used. Joseph Engler shared his observations of Oregon spotted frog habitat use at Conboy National Wildlife Refuge. Harriet Allen provided constructive suggestions that improved this report at several points during its development. Illustrations by Jim Hunter and illustrations and cover design by Darrell Pruett add a little bit of life to this report. On the cover is a photograph taken by William P. Leonard which provides a view of Oregon spotted frog breeding habitat at Trout Lake Marsh. July 1997 vi Washington Department of Fish and Wildlife EXECUTIVE SUMMARY The Oregon spotted frog (Rana pretiosa) is a Pacific Northwest endemic recently differentiated from a close relative, the Columbia spotted frog (Rana luteiventris). Historically, the Oregon spotted frog occurred from southwestern British Columbia south to the northeast corner of California. In Washington, the Oregon spotted frog was historically found in the Puget Trough from the Canadian border to the Columbia River and east into the southern Washington Cascades. Oregon spotted frogs breed during late winter or early spring. The low-volume calls of the males resemble the sound of the distant tapping of a woodpecker. Females lay their eggs in traditional communal oviposition sites; areas of shallow, still or slow-moving water and sparse, emergent wetland vegetation. Eggs hatch in 18 to 30 days and the tadpoles grow and develop for 13 to 16 weeks prior to metamorphosis in mid-summer. Oregon spotted frogs mature and begin breeding at two or three years of age. Oregon spotted frogs are preyed upon during all life stages by a wide variety of predators ranging from invertebrates that prey on eggs, to garter snakes (Thamnophis spp.) and herons (family Ardeidae) that feed on adults. Among the most significant of predators are various introduced species. Numerous warmwater fish species (primarily of the families Centrarchidae, Percidae, and Ictaluridae) and the bullfrog (Rana catesbeiana) have been introduced to waters within the historic range of the Oregon spotted frog. Because of their life histories and habitat affinities, these introduced species pose serious threats to Oregon spotted frog populations. Oregon spotted frogs are almost entirely aquatic in habit, leaving the wetlands only occasionally and for short duration. Wetlands associated with lakes, ponds, and slow-moving streams can provide suitable habitat. However, these aquatic environments must include a shallow emergent wetland component to be capable