[PDF] Conservation Assessment For The Western Pond Turtle In Oregon Actinemys Marmorata eBook

Author : Cristina Yarnal
Publisher :
Page : pages
File Size : 30,73 MB
Release : 2019
Category :
ISBN :

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This project provides insight into western pond turtle (Actinemys marmorata) population health at sites in three states on the western part of the United States. Washington, Oregon and California have identified the western pond turtle as endangered, a critical and a species of special concern in that respective order. Washington has implemented a recovery plan for western pond turtles and Oregon has established best management practices for the conservation of native turtles. California has yet to establish any guidelines for the conservation of western pond turtles. This species is endemic to the western United States and has been suffering from declining populations since the late 1800s. The factors that have contributed to the decline in western pond turtle numbers include: historical commercial food use, habitat destruction and fragmentation by water diversions, urbanization and agriculture, non-native species interactions, fire, drought, and flood which are increased by climate change due to anthropogenic activity. Reptiles in general do not do well with high disturbance rates in their environment, due to their slow movements. Western pond turtles have also been afflicted by different diseases, such as a respiratory illness that decimated one-third of the population in Washington and shell disease that has been affecting populations in Washington, Oregon and California. Exposure to diseases is proliferated by contact with released pet turtles, as captive turtles contain different bacteria. The western pond turtle sites analyzed are in the Columbia Gorge and South Puget Sound in Washington, Willamette Drainage in Oregon and sites in Lake County, San Diego County and Yolo County in California. These sites were analyzed through a combination of data from peer-reviewed, unpublished literature and government agency reports. The purpose of this research is to determine the effectiveness of management plans and strategies used for the recovery and conservation of western pond turtle populations, with an emphasis on head-starting programs, non-native species removal, habitat restoration and enhancement. The results will be analyzed by looking at historical data and more recent results in relatively the same area to determine if the western pond turtle populations have increased or decreased at those sites, in order to best allocate resources and prepare management plans for the conservation of western pond turtle populations in California. The recommendations being propose are surveying and monitoring, collaboration, habitat restoration/enhancement, non-native species removal, head-start programs and land acquisition. The analysis between sites in Washington, Oregon and California showed some progress but requires further research.

Author : Barry S. Nerhus (Jr.)
Publisher :
Page : 60 pages
File Size : 28,43 MB
Release : 2016
Category : Pond animals
ISBN : 9781339687421

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Abstract: This study investigates the population dynamics, movements, and habitat use of a population of western pond turtles in Orange County, California from 2008-2012 using radio telemetry and mark-recapture data. Western pond turtles have been thought to be declining throughout their range. However, few studies have documented their status in southern California, where urbanization has changed the landscape drastically in recent decades. I individually marked 236 pond turtles using hoop-net funnel traps and estimated the population size at 308 individuals, which is the largest estimate reported in southern California. Mean capture per unit effort was 5.03±0.87. Mean female carapace length (CL) (142±14mm) was not significantly larger than males (139±14 mm). I also documented 20 nest and 9 estivation locations. Mean distances included 176 ±130.80 meters (m) and 91±58.6 m. These data identify the population demography, which can be a metric of population stability. Other known populations need to be estimated to determine their regional status.