Taking giraffes for a scientific walk

The giraffes at Whipsnade Zoo have been undergoing a walking test - to help researchers find out just how their incredibly long legs work.

The team, from the Royal Veterinary College, external, are studying the animals as they walk to find out whether being so tall is an advantage or a disadvantage when it comes to simply moving around.

The scientists also hope to solve the evolutionary mystery of how giraffes evolved from their more modestly proportioned ancestors.

BBC science reporter Victoria Gill reports.