SAN JUAN CAPISTRANO, Calif. (KABC) -- Mission San Juan Capistrano is known around the world for the swallows.
The migratory birds are said to return to the area every March 19.
Mission specialist Megan Dukett said even though some of the swallow legend is based in myth, it has stuck around for nearly 100 years.
"Birds don't adhere to a human calendar, but they do tend to come back every spring," she said.
The famous birds are even the subject of the hit 1940s Bing Crosby song "When the Swallows Come Back to Capistrano."
But even though visitors will find painted swallows on signs and buildings throughout the town, the swallow population has dwindled down to zero over the last 30 years.
"They've been in the area, just not nesting here," Dukett said.
So how do you lure the swallows back to the mission? Well you play their favorite song. For the last five years, researchers have been playing swallow songs on speakers to bring them back.
The mission folks have also built fake nests to help the swallows find a home instead of having to spend two to three weeks building a nest out of other materials.
There's been good news with the efforts. Dukett said she was walking the mission grounds and noticed one swallow and then found a mud nest.
The swallows have brought in the attention of tourists and if you listen closely, you can hear the sounds of baby swallows. For each nest, there will be up to four hatchlings.
The hatchlings could kick-start a cycle that can bring hundreds of swallows back to the mission.
Famous Mission San Juan Capistrano swallows slowly coming back