A big cat expert at the University of Minnesota says trophy hunting is depleting the lion and cougar populations in Africa and the western U.S.
Craig Packer has spent years studying African lions. His latest report says wildlife managers often use hunting to control, rather than conserve, populations of predators.
He says in states and countries where hunting of cougars, leopards, and lions has been the most intense, populations have declined most drastically.
Packer says it's understandable, because wildlife managers in Africa are under pressure from local populations that suffer from lion attacks on wildlife and occasionally people. The same is true in the western U.S., where cougars are regarded as pests that prey on livestock.
By contrast, bear populations in western states are thriving.
Among big cats, when a male is killed, another male will kill his cubs in order to mate with the female. That means killing a mature male causes serious social disruption, and results in more deaths than just that of the trophy animal.
He says hunters could help keep populations in balance.
"But it needs to be regulated in a way that recognizes that the lion populations are very vulnerable to overhunting."
Packer advocates regulations requiring that hunters only shoot lions at least five or six years old. At that age, they have reached their reproductive potential and are vulnerable to competition from younger males who are likely to kill them anyway.
The article is published in the journal Public Library of Science.