Habitat restoration project in Oceanside hopes to lure cactus wrens, California gnatcatchers

Cactus wrens and California gnatcatchers may soon return to a former farm at the northern border of Oceanside near Camp Pendleton, a place where for decades they were pushed out by dairy cows.

The Buena Vista Audubon Society has announced a $3.5-million habitat-restoration project for 31.3 acres that the nonprofit environmental organization purchased last year near Whelan Lake.

“There was a lot of grazing, and it had basically been cleared of native vegetation,” said Audubon Society member Brian Petersen.

Now the vacant property is covered with persistent, invasive non-native species such as mustard and fennel, which are difficult to remove.

Three types of native habitats will be established, Petersen said Wednesday. Most of the property will be planted with different types of coastal sages and similar plants, such as buckwheat, that are home to birds like the gnatcatchers.

Some of the land will be restored with maritime succulents such as prickly pear and cholla cactus, the habitat for cactus wrens, and some will be planted with native vegetation such as needlegrass, which once dominated the state’s grasslands.

“The first couple of years are just weed control and planting a few things,” Petersen said of the projected six-year timeline. Some organic material will be added to improve the soil, but most of the natives will be planted a year or more after the exotics are gone and the soil is more accepting.

The project includes a $1.6-million endowment, set up by the Department of the Navy with the National Fish and Wildlife Foundation, to pay for the ongoing maintenance of the property once the native plants are established.

Most of the money to purchase the land also came from the Navy and the California Department of Natural Resources to mitigate activities by the Marine Corps at Camp Pendleton.

“This project would likely have remained an unattainable dream if it were not for the Marines,” Audubon Society President Curt Busk said in a news release. “It’s very exciting.”

The new preserve will provide quality habitat for sensitive native species and will serve as a natural buffer between existing development on the west, Oceanside’s restored willow flycatcher mitigation site and the Whelan Lake Bird Sanctuary to the east, he said.

“Equally important, it will be a protected link for wildlife moving between the 70-mile riparian corridor of the San Luis Rey River and the vast natural grasslands and mixed habitat found on the 125,000-acre U.S. Marine Corps base at Camp Pendleton.”

The preserve will include a short public trail leading to a scenic overlook of the preserve, Whelan Lake, the San Luis Rey River and the hills of the nearby Marine Corps base.

The land was once part of a large dairy farm founded and operated by the Whelan family through the 1980s. Some of the old dairy buildings remain on the nearby 73-acre Whelan Lake bird sanctuary, which is owned by a private foundation. Other parts of the old farm are now a city golf course and sewage treatment plant.

Whelan Lake, which was created to serve the dairy farm, is a sanctuary for resident and migratory waterfowl and is not open to the public except by special arrangement with the Audubon Society. More than 170 species of birds have been seen there, including Canada geese, willow flycatchers, least Bell’s vireos and 15 different species of ducks.

philip.diehl@sduniontribune.com

Diehl writes for the San Diego Union-Tribune