San Diego Management & Monitoring Program


Habitat Assessment and Baseline Surveys for the Western Spadefoot (Spea hammondii) and the Western Pond Turtle (Emys marmorata) on the Irvine Ranch Land Reserve

Type: report

Article abstract: Recent conservation planning for Orange County identifies the western spadefoot (Spea hammondii) and western pond turtle (Emys marmorata) as species requiring protection (NCCP/HCP, 1995). The western spadefoot is listed as a federal species of concern, a California Department of Fish and Game (CDFG) species of special concern, Bureau of Land Management (BLM) sensitive species and Natural Community Conservation Plan (NCCP) County of Orange target species. The western pond turtle is listed as a federal species of concern, a CDFG species of special concern, a BLM sensitive species, and a United States Forest Service sensitive species. Initial surveys of Irvine Ranch lands for the western spadefoot (coastal reserve only) and the western pond turtle were conducted in 1995 and 1997, respectively. The United States Geological Survey (USGS) conducted surveys in 2003 and 2004 to 1) identify currently occupied habitats and 2) assess population status for these two locally rare species within the Irvine Ranch Land Reserve (IRLR). USGS surveys encompassed portions of both the IRLR coastal and central reserves. Western spadefoots were found to be widespread in the central reserve, occurring in all six surveyed areas. In the coastal reserve, western spadefoots were detected in two of the six surveyed areas. Western pond turtles were detected at 4 of the 32 surveyed area on Irvine Ranch lands, all west of Interstate 5. Western pond turtles were detected at the University of California, Irvine's (UCI's) San Joaquin Freshwater Marsh and adjacent portions of the San Diego Creek Channel. At two sites, Bonita Canyon and Strawberry Farms Golf Course only a single western pond turtle was detected. Currently the largest populations of western pond turtles within the IRLR are at the Shady Canyon turtle pond mitigation site. The success of The Irvine Company's (TIC) mitigation effort at the Shady Canyon turtle pond indicates successful turtle habitats can be created and maintained. This report summarizes USGS's habitat assessment of the baseline surveys of both the western spadefoot and western pond turtle on Irvine Ranch Land Reserve, and provides recommendations for management to conserve these species within the IRLR.

Number of pages: 56

Authors: Fisher, Robert N.; Trenham, Peter; Schuster, Sara L.; Backlin, Adam R.; Hathaway, Stacie; Touré, T’Shaka A.;

Year: 2004

Prepared for: The Nature Conservancy, Newport Beach Office;

Prepared by: U.S. Geological Survey, Western Ecological Research Center;

Keywords: California Species of Special Concern; federal Species of Concern; NCCP; sensitive species; southwestern pond turtle; western spadefoot toad;

Species: Western spadefoot; Southwestern pond turtle