Wildlife populations fall by two thirds in 50 years around the world

David Attenborough meets a Leatherback turtle - Picture: Gavin Thurston 

Global wildlife populations have declined by more than two thirds in less than 50 years, a new report has warned.

Conservation charity WWF said nature was in "freefall" due to human activity, mainly intensive agriculture and the destruction of habitat such as forests to produce food, as it published its latest Living Planet Report.