Habitat restoration efforts in the San Dieguito River Valley Park are underway to save the coastal cactus wren, an imperiled bird species unique to Southern California whose population was hit hard by the October 2007 wildfires.
The cactus scrub around Lake Hodges and the San Pasqual Valley is considered a stronghold for the coastal cactus wren and the federally threatened gnatcatcher. The wren nests in prickly pear cactus and the gnatcatcher in low, woody sage scrub.
More than 60 percent of the river park burned last year, including these prime nesting areas.
"If their habitat disappears, they are going to disappear," said Leslie Wollenweber, resource specialist for the San Dieguito River Valley Conservancy.
About 75 acres of cactus scrub will be replanted, thanks to grants totaling $400,000 from the San Diego Foundation's After-the-Fires Fund 2007. The Conservancy, Urban Corps of San Diego and Conservation Biology Institute all received funding to contribute materials, man-power and monitoring of the park's recovery process.
Work began on Coastal Clean Up Day Sept. 20; about 25 volunteers took the first step to rebuild habitat by clearing weeds, which had completely overtaken a burned hillside along Lake Hodges.
"It gives you a good feeling to help do something to benefit the local lake," said 14-year-old Scott Watson, who volunteered with other members of his Boy Scout troop.
After mustard, pepper weed and other invasive plants are removed; native prickly pear and coastal sage scrub can be planted. However, it will take several years before the cactus is tall enough to support nests.
"We're hoping the birds can hang on," Wollenweber said.
Numbers of coastal cactus wren, a sub-species unique to Southern California, was already declining for unknown reasons, so restoring habitat for the remaining few is that much more critical, Wollenweber said.
Recovery efforts will focus on enlarging the small patches of healthy, unburned cactus scrub, where a few birds have been sited.
Habitat must be rebuilt close to existing nests because the cactus wren does not travel more than a mile from its home. The birds might never find habitat restored even two miles away.
The restoration project is expected to continue into next year. The Urban Corps of San Diego will provide most of the man-power for the clearing and planting, as well installing and repairing fences and watering supplies.
However, volunteers are always welcome to participate in monthly work parties throughout the river park, which spans from Dog Beach in Del Mar 55 miles inland to the river's source on Volcan Mountain.
"We couldn't do a lot of the work without the help of volunteers," said Park Ranger Jake Gibbs. "It's always awesome, especially, to have young people come out and learn about the environment."
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