It’s a century-old tradition that has waned in recent years, the annual migration of cliff swallows — those diminutive birds that live in mud nests along vertical walls — from Argentina to Orange County’s Mission San Juan Capistrano.
Though fewer and fewer seem to return each year, the celebration for their arrival hasn’t diminished.
On Tuesday, residents and schoolchildren alike will celebrate St. Joseph’s Day and the fabled return of the swallows to the mission, an Orange County tradition that goes back generations. People used to say you could set your clock to the birds’ arrival.
Mission officials are honoring St. Joseph — spouse of the Virgin Mary — and the swallows’ arrival by ringing the mission’s historic bells and offering live performances by a mariachi band and flamenco dancers.
Tuesday is stoked in tradition for the mission, but much has changed in recent years. As fewer of the birds have returned since they were first welcomed onto the grounds nearly 100 years ago, mission officials have tried different ways to lure them back.
This year the mission is playing swallow mating calls from speakers behind a statue of Father Junipero Serra, the mission’s founder. The recorded mating sounds had some success in 2012, mission officials said. They hope the momentum will carry forward.
Experts blame the swallows’ disappearance on urbanization. Mission restoration projects in recent years have also scared off the avians.
“I think if we keep trying long enough, eventually, some individuals will come by, they’ll see the mission and they will realize it’s a good place to nest, as they did in the past,” said Charles Brown, a swallows expert from the University of Tulsa in Oklahoma.
But as a recent study shows, the swallows are adjusting to a changing world. A study published Monday in the journal Current Biology shows the birds have developed shorter wingspans, making them take off faster and turn quicker to avoid modern-day hazards like moving vehicles.
— Joseph Serna
Photo: A bird sits atop a cross at Mission San Juan Capistrano during St. Joseph's Day in 2012. Credit: Mark Boster / Los Angeles Times