Cairo zoo puts lions on human birth control pill
31 August 2010 Last updated at 04:52 BST
Vets at Cairo's Giza Zoo are experimenting with birth control on their rapidly expanding population of lions.
They are taking the unusual step of giving the big cats human birth control pills after a population explosion that means there are now 53 lions at the zoo.
It is a controversial move in a zoo which has already been criticised by animal rights activists.
Jon Leyne reports from Cairo.