Many animals dwell in the wild kingdom that literally are 'poles apart' in structure, habits and adaptations. In the laboratory and in the wild, Marlin Perkins and Jim Fowler explore and explain such extreme contrasts such as: the slow heartbeat of the elephant and the rapid beat of a mouse; the alligators' jaws built to crush and a tropical bird's beak built to pry; birds that migrate and birds that 'stay put'; a bird that flies a mile a minute and a sloth that travels a food a day.