Some of the most unusual and versatile of all the mammals are the groups that live, feed and reproduce underwater. In this free course, Studying mammals: Return to the water, we will see how these formerly land-based mammals adapted to a return to the water, discussing such challenges as breathing, movement and communication. This is the seventh course in the Studying mammals series.
NOTE: The Studying mammals series is gradually being updated and replaced. You can study an improved freestanding version of this course, titled Aquatic mammals, here: