A survey of birds of prey across Botswana has confirmed what conservationists feared - that vultures are fast disappearing from one of Africa's greatest wilderness areas.

The project to count the birds involved driving more than 20,000 kilometres across Botswana, following a route originally taken by scientists more than 20 years ago.

Arjun Amar of the the University of Cape Town tells BBC Newsday that other birds of prey - like the African hawk eagle and African fish eagle - are also showing a sharp decline in their numbers.