I’ve been making recordings with my little Sansa “Clip”. It has exceptional fidelity in a little inexpensive package. I use Audacity to clean the files up a little.
Here is a recording of an hour of a little rapids on the San Marcos river, around midnight on the Spring Equinox, 2009:
Here is a half hour of the same rapids from 6:45 to 7:15 the next morning. First, there is just the rapids, then, a couple of minutes in, a bird sings, and by the end, there are dozens of birds singing.
We went camping in Louisiana during the spring, and here is about a half hour of bullfrogs and insects around midnight in one of the swamps:
Then, in May, I went hiking in the Red River Gorge in Kentucky, and here is a little of a small burbling stream we went by: