Cactus Wren, Coastal cactus wren
City of San Diego, Public Utilities Department Watershed and Resource Protection Team
San Diego Association of Governments; San Diego Zoo Institute for Conservation Research; San Dieguito River Park; San Dieguito River Valley Conservancy
Goal: Protect, enhance, and restore suitable cactus scrub habitat for coastal cactus wrens to increase effective population size in each genetic cluster at a short term sustainable level (e.g. 50-100 wrens), rehabilitate habitat destroyed by wildfire, improve habitat quality to maintain populations during drought, enhance connectivity within and between genetic clusters to increase genetic diversity and rescue small populations, and manage anthropogenic predation risk to ensure the long term persistence (>100 years) of cactus wrens on Conserved Lands in the MSPA.
Management units: 5, 6
In 2017-2021, continue supporting restoration of cactus scrub based upon ICR's Restoration Analyses for the San Pasqual Valley/Lake Hodges coastal cactus wren genetic cluster (see occurrence table) to: rehabilitate cactus scrub destroyed or degraded by the 2007 Witch Fire; to expand occurrences, particularly adjacent to Lake Hodges; to improve connectivity within the genetic cluster; and as needed, to manage high risk of anthropogenic predation of adults and nestlings.
|IMP-1||Following best practices, design cactus scrub enhancement and restoration projects to provide high quality nesting and foraging habitat with large patches of cacti >1 m tall in a mosaic of open scrub that provides sufficient food resources for reproduction and survival, especially during drought years when arthropod food resources are limiting. As they become available, incoporate the results from the Cactus Wren Demography, Foraging and Arthropod Study to create restoration palettes that favor plant species associated wtih important wren food resources. Design planting layouts to maximize water availability by allocating a portion of the plantings to more mesic sites, such as ravines, at the bottom of slopes, and on northerly and easterly aspects. Control invasive nonnative plants to =20% absolute cover to reduce competition with native plants for water and light.||in progress||Hodges Reservoir-Bernardo Bay Cactus Wren Habitat Restoration Grant Project|
|IMP-2||Implement management actions, as needed, to reduce anthropogenic predation on wrens and their nests in fragmented habitats bordered by development where wrens are vulnerable to predation by cats, Cooper's hawks, corvids and other human-subsidized predators. Actions could include removing selected trees within or bordering cactus scrub that provide hunting, roosting, and nesting perches for hawks and corvids and avoiding cactus scrub restoration in areas where the terrain and location make wrens especially vulnerable to predation. Other measures could involve humanely removing feral cats from Conserved Lands and providing educational material and signage encouraging neighboring homeowners to keep their cats indoors so that wrens are protected and cats are safe from predation by wild animals, such as coyotes.||in progress||Hodges Reservoir-Bernardo Bay Cactus Wren Habitat Restoration Grant Project|
|By 2021, =2 High Priority Management Actions Implemented from ICR's Restoration Analyses for the San Pasqual Valley and Lake Hodges||2021|