This is BirdNode.

Let's talk about nests.

Every spring, Robbins build their cup-shaped nests using grass and mud.

Orioles weave a hanging sack.

It takes a week or two.

It's hard work, and yet, once the chicks' fledge,

mostly the structures won't be reused.

Cliff swallows, on the other hand, will often reuse nests.

They'll spend a week plastering their mud structure on a sheer cliff face.

Use it, and the next year, unless parasites have moved in before them,

fix it up, and they're good to go.

Bigger birds, herons, hawks, or eagles often reuse a nest for many years.

One bald eagle pair in Vermillion, Ohio,

reused the same nest for 34 years,

adding branches each year until it weighed more than two tons.

But Europe's migratory white storks get the award for best reuse.

One nest site, still used in 1930,

and likely seeing many repairs over the years, dated back to 1549.

That's a continuous series of stork pairs nesting in one spot for 381 years.

For Bird Note, I'm Michael Stein.