Background sound such as birds, war, crockets, etc.

For my new documentary I need some background sounds like a quiet natural (wood) environment with only some birds in the neighboorhood, a heavy war-scene, a tropical night with the sound of crockets, etc.

Is there a database which you can recommend?

The sounds are meant to enliven a large amout of photo's.

(As far as I now, Adobe Premiere Pro doesn't have such a database itself.)