In the 1930s, a young Austrian scientist named Konrad Zacharias Lorenz formally documented the process of "imprinting" -- socially bonding to a parent figure.

Each spring and fall billions of birds hit the "flyways," atmospheric roads for annual migrations, which can stretch thousands of miles.

To help ensure the survival of endangered whooping cranes, Operation Migration maintains an artificial breeding program that prepares chicks for adulthood.

Biologists trying to restore eagle populations around the world face a difficult challenge. But there are success stories -- and the restoration of America's Bald Eagle is one of the most dramatic.

Wildlife adventures are becoming increasingly popular for "eco-tourists" interested in seeing and saving some of the planet's most endangered animals.