This is BirdNode.

Cliff swallows have returned from wintering in South America, and they're gathering in

nesting colonies.

A single colony in the west may contain up to 3,700 nests.

In the east, colonies are generally a bit smaller.

Look for swarms of these swallows under bridges, on cliffs, under the eaves of barns, or even

the side of a house.

They construct their gourd-shaped nests out of mud, side by side, and all jumbled together.

One parent usually guards the nest, often peaking out of the round opening, showing its

creamy white forehead patch.

Cliff swallows consume hordes of flying insects.

These birds have only five different calls, but one, a unique, squeak call, tells others

that they've found food.

So when one bird finds a swarm of insects, it spreads the word to its neighbors.

Perhaps part of the reason these birds thrive in large colonies.

Find out about bird-friendly ways to garden.

When you come to our website, birdnote.org.

I'm Michael Stein.

Support for Bird Note is provided by Jerry Tone and Martha Wycoff from Seattle, Washington,

and generous listeners around the world.