Central Reserve Cactus Wren Habitat Assessment and Survey

Type: report

Article abstract: A study to determine the status of the coastal cactus wren was conducted in the Coastal Reserve in 2006. The purpose of this study was to determine the status of the wren in the Central Reserve using the same methodology so that a baseline condition for cactus wren could be established reserve-wide. All of the cactus resources in the Central Reserve were mapped in the spring of 2008, and two rounds of focused surveys for the cactus wren were conducted in cactus scrub judged mature enough to support nesting pairs. Unanticipated fires burned approximately 75% of the Central Reserve in 2007, so methods were developed to collect data that would enable an evaluation of the impact of the fires on the cactus resources within those areas. A total of 1,855 acres of cactus scrub was mapped in the Central Reserve. Of that total, 1,420 acres sustained Low, Moderate, or High levels of damage during the fires, 75% of which (1,059 acres) was severely burned and is not suitable for supporting nesting cactus wrens. Six hundred eighty three (683) acres were judged suitable for occupancy by cactus wrens and surveyed. Within the 683 acres of cactus scrub judged suitable for occupancy by cactus wrens, 263 sites were delineated and surveyed for adult cactus wrens. Fifty eight (58) sites were found to be occupied during the first round of surveys, and 56 sites were found to be occupied during the second round of surveys. These occupied sites represent an estimated 67 territories, a decline of 82.1% since 374 territories were estimated in 2004.

Number of pages: 27

Year: 2008

Purpose: Determine the status of the wren in the Central Reserve using the same methodology so that a baseline condition for cactus wren could be established reserve-wide.

Prepared for: Nature Reserve of Orange County;

Prepared by: Leatherman Bioconsulting, Inc.;

Keywords: Cactus Wren; central reserve; habitat assessment; NROC; Orange County;

Projects: