Michael Ellis: Cliff Swallows

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Swallows are a graceful, migrating bird long identified with a historic Orange County mission. Michael Ellis has this Perspective.

Swifts and especially swallows are the dominant diurnal insect predators. When the bats call it a night, these birds take over. All of these critters do make the world more pleasant for you and me. We have seven species of swallows in the Bay Area - barn, violet-green, tree, northern rough-winged, cliff, bank swallows and purple martins. The latter two species are quite uncommon.

But there’s one of these swallows on a mission. That is, on the Mission called San Juan Capistrano. Yes, those so-called Capistrano swallows are more accurately known as cliff swallows. And do these world-famous birds actually arrive on March 19, St. Joseph’s Day, as promised by that city’s Chamber of Commerce? Well, not exactly, but pretty close.

If you’re an exclusive insect eater in the temperate zone and the cold of winter causes your food supply to dwindle, you have two choices. You can hibernate like some bats do, and one bird called the poorwill does as well. Or you can migrate to where there’s an abundant supply of insects. Beginning in September cliff swallows fly south, some all the way to Paraguay and Argentina. Large flocks of up to several hundred take a leisurely journey of about three months. And here they over-winter, again for three months finding ample insects to eat.

And then another slow journey back north. Swallows have what ornithologists call 'site fidelity,' and they return very close to where they were either raised or successfully nested the previous year. So, it is another three months in North America nesting and raising young before returning to the land of the gauchos.

And as their common name indicates, these swallows originally required cliffs for nesting. But human created structures like Catholic mission posts and especially bridges over creeks or rivers provide the ideal nesting habitat. Consequently, cliff swallows have actually expanded their range as humans have built more bridges and buildings. That’s some welcome good news.

This is Michael Ellis with a Perspective.

Michael Ellis is a naturalist and tour leader. He lives in Santa Rosa.