Mammals

Dolphin echolocation clicks (~80K aiff)

Was Flipper trying to tell us something? Find out what scientists think about all the ruckus dolphins and whales create. Plus, listen to "Marine Mammals' Greatest Hits". For her thesis, Kimberley Amaral has written a series of articles on oceanography/coastal issues for Woods Hole Oceanographic Institution. This is one of them. You'll find another in the Miscellaneous section.
http://www.umassd.edu/Public/People/Kamaral/thesis/marinemammalacoustics.html

"By watching the whales you can prolong the life of cetaceans as a species . This may be the last chance before they say goodbye for this Planet." Maybe so. The least you can do is visit this site. It could use a face-lift, but you'll find lots of interesting links.
http://www.physics.helsinki.fi/whale/

Snapshots of dolphins and some other whales by David Hofmann. There's a very large page featuring thumbnails of all pictures. Good links.
http://www.presair.com/usr/dhofmann/