Birdsong.

Clear rising whistles held year-round to defend territory.

Molts twice a year, drab winter to brilliant summer gold.

Often the first voice at dawn, a liquid caroling phrase.

Drums on dead wood to claim territory and dig cavities.

Walks headfirst down trunks; a tinny toy-horn call.

Caches thousands of acorns and recalls the hiding spots.

One of the most widespread birds on Earth.

A skilled mimic of the Red-tailed Hawk's scream.

Its mournful coo is often mistaken for an owl.

Adds more 'dee' notes to signal greater danger.

Its raspy scream is the raptor cry dubbed into films.

Recognizes individual human faces and holds grudges.

A soft warble that helped fuel a nest-box revival.

Weaves a hanging pouch nest; a rich flute-like whistle.

Crosses the Gulf of Mexico nonstop; fast squeaky chips.

Pairs duet with deep hoots; a crushing talon grip.

Learns 200+ songs, stringing borrowed phrases together.

Sings two notes at once for an ethereal flute song.

Its wail carries for miles across still water.

Crow-sized; a wild ringing cackle and rectangular holes.

Sacred to the Maya; males trail iridescent tail streamers.

Pairs mate for life and fly wingtip to wingtip, screaming.

A lightweight bill sheds heat; the call is a low croak.

Chicks have wing claws; ferments leaves like a cow.

Males lek, bobbing and squealing to win mates.

A confiding tanager with a high squeaky chatter.

Song dialects shift valley to valley across the Andes.

Secretive; a slow guttural gawking series.

Endemic to Mexico; green-and-orange male, sweet warble.

The largest flying parrot; cracks hard palm nuts.

A ringing yelp thrown over the shoulder — the voice of Africa.

Glossy blue and orange; an endless energetic chatterer.

Tumbling display flights with harsh rasping cries.

Named for its explosive 'haa-haa-de-dah' at flight.

Males knot trial nests; females tear the sloppy ones down.

Golden-crowned; trumpets a honking call while dancing.

One of Africa's most familiar birds; a cheerful warble.

Among the most accomplished vocal mimics of any animal.

The 'flying banana'; an accelerating tok-tok-tok cluck.

Noisy colonies; a wheezy swizzling chatter fills the trees.

A prized songster with a rich, ever-varying flute melody.

The peacock's far-carrying 'may-aw' often signals rain.

A brood parasite; a rising 'ko-el' heralds the monsoon.

A bold adaptable mimic spread far beyond native Asia.

Sings in winter and at night near streetlights.

Powerful night song of whistles, trills and crescendos.

Lays eggs in other nests; the two-note call names it.

A giant kingfisher whose cackling laugh marks dawn and dusk.

Brush-tongued nectar feeder; flocks screech at dusk.

An astonishing mimic — other birds, chainsaws, shutters.