This is Bird Note.

What is making that wonderful sound?

High in the mountains of Chiapas, the southernmost state of Mexico,

a male Highland Guan is performing his territorial display.

Looking like a slim turkey, two feet long and all black, the Highland Gwan perches on a tree branch, whistles, and then glides on vibrating wings. The resulting wondrous sound is like no other. The bird's display creates a sound emblematic of the cloud forest of El Triunfo Biosphere Reserve.

Clouds and fog roll frequently through the reserve, creating a lush forest wonderland.

Pramiliads and orchids cover massive tropical oaks.

Flute-like voices of Rufus-browed Wrens echoed through the forest.

In concert with glistening songs of brown-backed solitaire.

The endangered horned guan thrives here too,

a bird so scarce and secretive it was long thought extinct.

Cloud forest makes up less than 1% of the world's forest,

and its conservation is crucial.

At El Triunfo, the display of the Highland Gwan testifies to a conservation success.

For Bird Note, I'm Mary McCann.