"I have a colleague at London Zoo who was called out last year after the police spotted a 'big cat', only to find it was an ordinary ginger moggy, " he said.

BBC: News | UK | Home Counties puma alert

Once you're a political animal, you know where the big seat in the zoo is, and it's being president of the United States.

CNN: Cheney unapologetic in new documentary

The BBC spent a day with the "gorillas' cardiologist" while he visited his big patients at the zoo.

BBC: Healing the hearts of men and gorillas

The six-month internship at Cat Haven was her big break -- her ticket, she hoped, to getting a full-time job at a zoo.

CNN: STORY HIGHLIGHTS