A team of scientists reports they have developed an algorithm that predicts the most sustainable hunting quotas for lions in Africa.

The hunting of big cats for sport in Africa is controversial, with proponents championing the revenue the sale of hunting licenses brings to the nine African countries where trophy hunting is allowed, and opponents disdaining the killing of majestic animals for sport.

Writing in the journal Proceedings of the National Academy of Sciences, a team of conservation scientists from Imperial College London and the Universities of Stirling and Cape Town report their method for devising the most sustainable hunting quotas. Their method calculates for how long it takes to find and shoot a lion in a given area, then estimates how many males can be hunted while still allowing the overall population to grow.

The algorithm, when ran in an area with heavily depleted lion populations, found that if specific quotas generated by the algorithm are met, the number of adult males would increase from around 38 to 100 in three decades. In that same 30 years, the number of adult male lions that could be sustainably hunted would also rise, the researchers said, from 15 to 22 - an increase that would benefit hunters.

"Many people don't feel happy about the idea of hunting animals for sport, especially animals that are as beautiful and impressive as lions. However, in some areas, the money that comes in from hunting is what enables the land to be set aside for wildlife and this provides the lions with a home," said E.J. Milner-Gulland, one of the authors of the research from the Department of Life Sciences at Imperial College London.

"As conservation scientists, we want to ensure that populations of lions can thrive. Our model shows that it is possible for lion numbers to grow even where there is hunting, but this only works if you set quotas for hunting at the right level, and in many places this is not happening at the moment," Milner-Gulland said.

"Our new method for setting quotas relies on information that is easy for governments to get hold of and it should be simple for them to use. It could also be used to set reliable quotas for other animals which are hunted by searching for individuals, such as wild sheep or deer. The next step is for us to test the method in the field and if it proves successful, we hope it can be widely adopted," the researcher said.