http://www.cdemusic.org/soundfiles/environmentalsoundsamples.html

An exemple:
Bernie Krause coined the term ‘biophony’ to mean the sounds of nature (as against the sounds made by humans). The following recording, taken during a trip to the Amazon, is one of many on the CD that accompanies his book Wild Soundscapes, a fascinating, easy-to-read users’ manual for field recording, with practical advice on equipment, where to place microphones, and all kinds of explanations and information. More, Krause tells some wonderful stories and offers excellent examples. Recording a jaguar in the Amazon, as in the following excerpt, is simply charming.