This is bird note.

American crows stream by overhead in the late afternoon.

Rivers of crows.

These are crows on a mission.

They're headed to their night roost, a giant avian slumber party.

Gathering in a park or woodland, they land in a tree, then scuffle and squawk, filtering down through the branches.

Birds arriving late force the early birds lower into the trees.

Crow experts think the roost may provide benefit. the early birds lower into the trees.

Crow experts think the roost may provide benefits like warmth, protection from predators,

shared information about food sources, and a chance to find a mate. Immature crows may spend the night in the roost year round,

but adults of breeding age stay in their own nests

while raising their young,

then go back to the group after the fledglings leave.

So just how many crows are there in a roost?

That varies.

But at one long-time roost in Danville, Illinois,

locals have counted more than a hundred thousand

crows. Not that the folks of Danville are especially happy about that.

Imagine the ruckus when the first few thousand crows leave in the morning

about an hour before sunrise.

Follow crows to their roofs some autumn evening if you, and watch these avian acrobats wheel in for the night.

But if you go, just a word of warning,

...