Trophy hunting of lions, the killing of selected individual animals for sport, is highly controversial, and there is much debate about what it contributes to conservation. A new article highlights significant 'unknowns' that thwart conservationists from making any robust conclusions.

The authors note that we know surprisingly little about the causes of lion mortality, or even the amount of land used for lion trophy hunting. Similarly, the extent to which trophy hunting depends on lions for financial viability is generally unknown, and it is extremely difficult to predict what would happen to the land where trophy hunting currently occurs if trophy hunting were to cease.

It is clear, though, that the money needed to reverse the loss or reduction of species exceeds income from any form of tourism, including hunting. Innovative methods of funding conservation are needed, particularly in view of the expanding human population in Africa.