THE NATURE OF SEX spans the globe to illustrate how an astonishing diversity of life forms find their mates and conceive, raise, and protect their offspring.

THE NATURE OF SEX spans the globe to illustrate how an astonishing diversity of life forms find their mates and conceive, raise, and protect their offspring.

During the 20th century, as humans have encroached more and more on animals' territory, zoos have come to be more than just places to view wild animals.

Every animal has a story...and so does the staff at the San Diego Zoo.

Animal health care is an important part of the zoo's mission, and staff members pay daily "house calls" to residents.

Ironically, the powerful, dedicated canines profiled in Sled Dogs: An Alaskan Epic are little more than mutts. They are mixed-breed huskies that have endurance.

Ironically, the powerful, dedicated canines profiled in Sled Dogs: An Alaskan Epic are little more than mutts. They are mixed-breed huskies that have endurance.

Ironically, the powerful, dedicated canines profiled in Sled Dogs: An Alaskan Epic are little more than mutts. They are mixed-breed huskies that have endurance.

Ironically, the powerful, dedicated canines profiled in Sled Dogs: An Alaskan Epic are little more than mutts. They are mixed-breed huskies that have endurance.

Ironically, the powerful, dedicated canines profiled in Sled Dogs: An Alaskan Epic are little more than mutts. They are mixed-breed huskies that have endurance.