It’ll take $65,000, dozens of volunteer hours, planting of 1,300 seedlings and several years of monitoring to create 2 acres of coastal sage scrub habitat that could potentially host a single nesting pair of endangered California gnatcatchers.

But to consider only the numbers misses why volunteers like Peter Ridley spend days and even years working to bring damaged habitat back to livability for wildlife.

On a recent day, fresh off a rainstorm, the mud at the Bayview Restoration Project squished and clung to the bottom of volunteers’ boots. Dirt flecked their clothes and coated their gloves, and the waters of Upper Newport Bay cooled the air with the slightest breeze. Finally, a cloudy early morning gave way to sun-pocked skies and a bright afternoon.

Volunteers worked hard reviving this spit of land where the earth has been compacted hard by walkers and horseback riders, where native plants such as California buckwheat and California sagebrush have all but disappeared.

Yes, habitat desperately needs help: Less than 10 percent of coastal sage scrub habitat that once covered Orange County’s coastal areas remains.

And so on this day, 11 volunteers thrust shovels into the ground and carefully pack dirt around fledgling plants cultivated from seeds harvested in Orange County’s wilder areas. Behind them, a green lawn gives way to a neighborhood basketball court. In front, a slope of scrubby bushes gives way to the glimmering waters of Upper Newport Bay.

Years ago, something about Back Bay reminded Ridley of his homes in Connecticut, Philadelphia and Washington, D.C. So he started volunteering with the Newport Bay Conservancy in 2002 and now helps with restoration work almost weekly.

When he first drove along Back Bay Drive, “I said, ‘I’m home.’ So I said, ‘What can I do for the bay?’”

A lot, it turns out.

Restoration is long, hard work, and newly planted native shrubs must be cared for as they sprout. Invasive species must be uprooted.

For example, the recent rains have brought back mustard, an annual plant that after rain looks like patchy green clover and requires continual weeding while the native plants re-establish.

“Once the native shrubs get established, they’ll be able to out-compete the mustard by taking up space,” said Sarah Kimball, an evolutionary ecologist at UCI who is helping with the project.

“It’s only when there’s a disturbance like a fire or trampling of natives or a really bad drought that the mustard can get established.”

When the native scrub comes back, so might the California gnatcatchers, a small endangered bird that is unique to Southern California and that environmentalists have used to halt development.

One breeding pair that had lived in the degraded – soon to be restored – area moved just down the hill. But if the pair has chicks, a second pair of gnatcatchers could nest in the newly-restored coastal sage scrub.

“Our hope is we’d be able to support at least another pair of gnatcatchers,” Kimball said.

Contact the writer: aorlowski@ocregister.com