On March 19 bird lovers everywhere look forward to seeing and hearing about the beloved cliff swallows that migrate from Argentina to California.
For years and years, on this date, San Juan Capistrano, California, has celebrated the return of the swallows to the ruins of the old mission. But in recent years, the birds stopped coming to the mission.
The nests had been knocked down in the 1990s during renovation of the the beautiful old ruins. It was necessary to protect the structure against California's frequent earthquakes.
Scientists also believe that increased urbanization is a factor in the birds' changing habits. There are more trees and more structures that birds can nest in.
But scientists are trying recorded vocalizations to entice the swallows back to church.
"Contact calls," said Chapman University's professor of biology, Dr. Walter Piper, of the recorded vocalizations, "Calls that swallows give to each other when they're in flight. We're also playing courtship calls given by male cliff swallows that should be another indicator that there is a potential for breeding to occur in the area."
This is the second year of the vocalizations. So far, no swallows have returned to their old nesting grounds.
But Piper said cliff swallows have taken flight over the mission looking it over.
"We have hopes," said the scientist, "Our goal," he said, "is for the swallows to colonize the mission again and to start breeding there."
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