Western Pond Turtle PHVA (2012)

The western pond turtle (Actinemys marmorata) can be found in the lowlands of Puget Sound, southward through western Oregon and California into the northernmost areas of the Baja California peninsula. The species can be found in slow streams, wetlands, ponds and lakes. Where still extant, the species is typically found in small isolated populations across its range. By 1990, the western pond turtle population in the state of Washington declined to an estimated 150 animals remaining in the wild, prompting the Washington Department of Fish and Wildlife (WDFW) to classify the species as “Endangered” in 1993. Habitat degradation, disease, and predation by invasive bullfrogs were identified as the primary factors causing the population declines across the species’ range.

For the past 22 years, Seattle’s Woodland Park Zoo (WPZ) and WDFW have collaborated on a headstarting program in which turtle eggs or recently-emerged hatchlings are collected from the wild,
hatchlings are reared over the winter in controlled conditions at the zoo, and juveniles are released into wild habitats when they reach about ten months of age. Oregon Zoo joined the collaboration several years later. In accordance with guidelines set out in the 1999 Washington State Recovery Plan for the species, four populations are to be established in the Columbia River Gorge and three in Puget Sound. This Western Pond Turtle Recovery Project is a collaborative effort among partners from Woodland Park Zoo, Oregon Zoo, Washington Department of Fish and Wildlife, U.S. Fish and Wildlife Service, U.S. Forest Service and Washington State Parks.

As a result of this intensive recovery effort, researchers estimate the western pond turtle population in Washington to be approximately 1,200 – 1,500 individuals. The turtles are found today at six sites: two in South Puget Sound (SPS), the “Mason County site” and “Pierce County site”; and four along the Columbia River Gorge (CRG), the “Sondino site”, the “Bergen site”, the “Pierce National Wildlife Refuge (NWR) site” and the “Homestead site” (more precise locations are not identified in this report for security reasons). Despite this success, project managers remain concerned about the continued predation threat posed by invasive bullfrogs and other predators and limited extent of habitat available for population recovery. Additionally, recent observation of ulcerative shell disease that may affect 30% or more of animals released to the wild is an increasing cause for concern. Project managers are interested in a current evaluation of the Western Pond Turtle Recovery Project to assess threats to the species using the best available scientific information and tools, thereby further strengthening prospects for recovery in the wild.

To initiate and inform this effort, species conservation staff from the WPZ sought the assistance of the Conservation Breeding Specialist Group (CBSG), part of the Species Survival Commission (SSC) of the International Union for Conservation of Nature (IUCN), to design and facilitate a Population and Habitat Viability Assessment (PHVA) workshop process with members of Washington’s Western Pond Turtle Recovery Team and associated species experts and stakeholders.

North America
Document Type: 
PHVA Reports