Conservation

conservation2Conservation of the Western Pond Turtle

The Western Pond Turtle (WPT) population has seen a significant reduction in numbers in its native range. Holland (1994) estimates a historic population of anywhere between 60,000 and 90,000 individuals in the Willamette region, with current levels between 1500 and 2400 turtles. In the Willamette River drainage basin the species is thought to be down 96%-98% from its historic population level (Holland, 1994) and it has become extirpated in British Columbia and most of Washington (Bettelheim, 2004). This significant crash in population is the result of numerous threats to WPT survival. Habitat loss is a serious issue in part due to the filling of wetlands for human real estate development. WPTs are also threatened by the introduction of invasive predators such as bullfrog (Rana catesbeiana) and largemouth bass (Micropterus salmoides) that eat hatchlings and juveniles, resulting in low recruitment levels and contributing to population decline. Industrial and agricultural contaminants can make water unsuitable for WPTs to live in. Invasive plant species like Himalayan blackberry (Rubus discolor) and reed canary grass (Phalaris arundinacea) have reduced areas suitable for nesting by covering packed earth with impassable vegetation. Exotic turtle species such as the red-eared slider (Trachemys scripta elegans) often out-compete WPTs in their native range and frequently carry diseases that only exacerbate WPT mortality (Holland, 1994).

Faced with all of these challenges, it is no wonder that the WPT is in a state of decline. The United States Fish and Wildlife Service regards the WPT as a “Species of Concern” though it dismissed the proposal to list the species as threatened or endangered on the basis of insufficient scientific evidence. The Oregon Department of Fish and Wildlife lists the WPT as Sensitive – Critical, which means that a listing of threatened or endangered is pending and actions are desired to prevent that listing. The WPT is listed as endangered by the Washington Department of Fish and Wildlife (Bettelheim, 2004). Because the WPT is not listed under the Federal Endangered Species Act there are no laws requiring protection of the animal or its habitat. Nonetheless, the U.S. Fish and Wildlife Service encourages volunteer-initiated conservation efforts for the WPT in an attempt to keep it from being listed in the future (USFWS, 2001).

In light of the many woes of the WPT, conservation efforts are being made to assist this fragile species. These efforts are not required by federal law, but are an effort to preempt future expenditure and legislation that would no doubt result if the species were listed as threatened or endangered in the future. By learning more about the distribution and natural history of the WPT, researchers hope to gain a better understanding of how to assist the turtles. The research discussed in this report is only one of many studies and projects designed to aid the WPT in recovery. What follows is a discussion of some of the projects that have been done in the past and that have informed this one. Learning about past projects can teach us what has worked and what hasn’t in WPT conservation and provides a strong information base from which to frame our own research.

In 2002 and 2003 the Western Pond Turtle Working Group (WPTWG) and local watershed councils set up a survey to obtain more comprehensive data about the presence of the WPT in the Willamette River Basin. The study was conducted in 2002 and 2003 and revealed a wide distribution of WPTs within the region, though only 112 twelve sites definitely visited by WPTs were reported (Adamus (a), 2003). As a follow up to the initial report, the WPTWG put out another paper containing recommendations for restoration and management practices to aid the WPT, including adding basking structures, re-contouring channels, and restoring wetlands (Adamus (b), 2003).

The United States Army Corps of Engineers conducted an additional study of the WPT in 1993 at Kirk Pond near Eugene, Oregon. The study used a combination of visual survey, trapping, radiotelemetry, visual mark-recapture, and nest, juvenile, and hatchling searches to gather data on population age and sex distribution, density, range, and habitat conditions. Nest exclosures were placed over nests to protect the eggs from predators, new basking structures were placed, and a wetland restoration project was conducted in Kirk Park to aid turtle recruitment and survival (Leatham, 1994).

The Friends of Buford Park at Mt. Pisgah near Eugene, Oregon worked on WPT habitat restoration as part of their South Meadow channel restoration project beginning in 2003. A side channel was connected through the meadow and a backwater added, creating new slow-moving water, ideal for turtle habitat. Western pond turtles have already been seen using the new channels and future plans for continuation of the restoration will likely improve the habitat even more (Jones, 2007).

The western pond turtle is undoubtedly a species of concern and awareness needs to be raised to help it rebound. Fortunately there is hope for this at risk reptile. The multiple studies and conservation efforts carried out by diverse agencies in the turtles’ range are building a knowledge base about the species and giving it a fighting chance for the future.

Conservation efforts in Oregon

Fish WIldlife Science http://wdfw.wa.gov/science/articles/pond_turtle/index.html

Conservation Efforts in Washington

Washington Department of Fish and Wildlife http://wdfw.wa.gov/wlm/diversty/soc/recovery/pondturt/wptxsum.htm

Woodland Park Zoo http://www.zoo.org/conservation/pond_turtle.html