When the Swallows Come Back to Capistrano
Lyrics by Leon Rene
“When the swallows come back to Capistrano
That’s the day you promised to come back to me
When you whispered, “Farewell,” in Capistrano
’twas the day the swallows flew out to sea”
The above lyric refers to the reliable migratory return of the cliff swallow (Petrochelidon pyrrhonota), fabled to occur annually on March 19th, to the Mission San Juan Capistrano in California. Although not nearly as punctual, the Cliff Swallows of Central Texas will return from their winter home in South America in March and April to begin their breeding season. Although once a bird of the American West, they are the rare species who has flourished under infrastructure expansion. With each new bridge and culvert, we see their habitat expanding rather than disappearing, and they can now be found as far east as the North Atlantic coast.
Cliff Swallows are among the most social landbirds of North America, with their nests ranging in number from 200-1000 in a single colony. Their gourd shaped nests are made from mud pellets the birds collect from nearby stream beds and each nest can be constructed of up to 1,000 pellets! The largest recorded colony was in Nebraska and had a whopping 3700 nests. Living in such close quarters has its advantages. This highly adaptable bird will observe its neighbors foraging success and learn food locations from other colony residents. They also have developed a highly sophisticated vocal system used for distinguishing their young in creches, or large congregations of birds outside the colony. Cliff swallows have also been known to lay their eggs in another swallow’s nest, a behaviour known as brood-paratization.
Keep an eye out for these fun birds in the spring. Their diet consists of many types of flying insects including flies, bees, wasp, ants, beetles, lacewings, mayflies, butterflies, moths, grasshoppers, crickets, dragonflies, and damselflies. They can often be seen swooping down for a sip of water from lakes and rivers – even swimming pools! The colonies are easily identified by the gourd shaped nests found under bridges and overpasses, typically near a water source. While out foraging, look for their square-tail with a cream colored forehead, metallic dark blue backs and pumpkin colored rump.
Where to see them this spring in Austin: Look under intersection bridgeways (like Pennybacker bridge!), overpasses & culverts.
