Cambrian: Opinion

This bird’s place in ecosystem isn’t hard to swallow

Barn swallows, seen here, can be distinguished from cliff swallows by their forked tails.
Barn swallows, seen here, can be distinguished from cliff swallows by their forked tails. Special to The Cambrian

The swallows are back in town!

One of the many joyful sights this time of year is the graceful swooping flight of the swallows as they nest on the sides of buildings, under eaves and on San Simeon Pier.

Swallows nest throughout California, and the Central Coast is no exception. In fact, swallows are so abundant around here that Swallow Rock is a Cambria landmark. Several species of swallow can be found on the Central Coast, but the two we are most likely to see close to town are the barn swallow and the cliff swallow. Both utilize buildings and other man-made structures to build mud nests.

Barn swallows seem pretty much unafraid of people and will brazenly build nests under the eaves and overhangs of local shops and restaurants. It is a delightful surprise to glance up and see a swallow in a mud nest staring grumpily down on the flow of tourists just a few feet below.

Swallows spend their winters in South America, migrating to North America in the spring. They arrive just as the flying insects are hatching out, providing abundant food for their growing families. Swallows feed on the wing, consuming bees, flies, wasps, butterflies, moths and all other kinds of flying insects.

The most famous nesting site for cliff swallows in California is San Juan Capistrano, in San Diego County. In recent years, the swallows have not returned to the old mission there. Biologists suspect that improvements to the structure may have disrupted nesting activities.

Both barn swallows and cliff swallows use mud to build their nests, which have similar but slightly different shapes, and will vary depending on what kind of structure they are building upon. Male and female work together to collect mud in their bills and form it into pellets. Swallows may also spiff up old nests by removing feathers and adding fresh mud pellets.

The parents line the nest with grass, feathers or both. Usually fewer than six eggs are laid, with an incubation period of about two weeks. Within a month of hatching, nestlings have fledged and are about the same size as the adults. Fledging of the first brood may prompt the parents to go for a second round.

If you are not sure what species of swallow you are looking at, look at the tail. The barn swallow is the only North American swallow with a deeply forked tail. Barn swallow plumage is a stunning combination of bright cobalt blue on the back and a tawny underside. Cliff swallows have dark red faces with dark blue backs and rust-colored rumps. Adult cliff swallows have a bright white patch, like a headlamp, on the face.

It was the hat-making trade’s impact on barn swallows that prompted naturalist George Grinnell’s editorial in Forest & Stream in 1886, decrying the waste of bird life for fashion. This colorful little bird, and its near devastation, led to the founding of the first Audubon Society. So, remember to say thanks to the swallow, and keep eating those bugs!

Michele Roest’s column appears monthly and is special to The Cambrian.