namibias etosha national park has around 400 wild lions. they generate millions in tourism revenue. as the top predator, theyre vital to the delicately- balanced eco-system. but in recent decades, theyve been trapped, poisoned or shot. experts estimate their numbers have been halved in the last 50 years. >> obviously, we want to protect and conserve the lions, but on the other hand we need to find solutions for this conflict. and the farmer has a problem, he has a real problem because this fence is not being maintained, nobody's really sure whose responsibility it is. there's no one in a position to really find a solution for these issues except ourselves. >> in recent years, africat has upgraded so-called "hot spots" along etoshas southern fence, using spare tires for instance to allow smaller animals to get through. while stopping the lions. these improvements have dramatically reduced livestock losses. but the fence is 830 kilometers long. by the time, youve repaired one hole, the next has opened. >> its a warthog track. very fresh in fact, since the last rain. and it's moving, i