Hi,
This morning before taking my dogs on their walk I listened to this very sobering recording.
It opens with a great song as introduction. It plays a recording in an area, and then a second one 10 years later in the same spot. Martyn Stewart then goes through a short process of removing bird songs in layers, and you can literally hear the progression of what the future may well hold.

It is an eye opening recording, not terribly long, but makes its point. I tested the link to make sure it works.

http://naturesound.libsyn.com/index.php?post_id=367422

Vicki Biltz
Bonney Lake Wa