"There should also be a greater effort from the hunting industry to self-regulate and ensure that unscrupulous elements are weeded out."
Trophy hunting has a bad reputation in the developed world, due in part to indiscriminate hunting by early European settlers, Lindsey observed.
But hunting has also been credited with facilitating the recovery of species, Lindsey's team argues in its paper.
The southern white rhinoceros grew from just 50 animals a century ago to over 11,000 wild individuals today, because hunts gave game ranchers a financial incentive to reintroduce the animal, the authors write.
Trophy hunting has also driven the reintroduction of cape mountain zebra and black wildebeest in South Africa, Lindsey said.
Hunters typically take just 2 to 5 percent of males annually from hunted animal populations, he added, which has a negligible effect on the populations' reproductive health.
Many animal rights groups remain fundamentally opposed to killing animals for sport.
"The idea of trophy hunting as a conservation method is an extremely tricky and contentious issue that generates disparate views from people all of whom claim to want the best for animals," said Marc Bekoff a behavioral ecologist at the University of Colorado in Boulder and author of The Emotional Lives of Animals.
Bekoff said that while the certification program is a good idea, he has difficulty believing it could work well in practice, because the bureaucracies involved in such regulation would be complex.
"It's hard to believe that the situation has reached the point where killing is the best way to conserve," he said. "There have to be more humane alternatives."
In late February South Africa announced long-awaited legislation against so-called canned hunting, in which animals are shot in cages or are tranquilized and released shortly before being gunned down.
The ban will take effect June 1 under a law that also bans hunting with bows and arrows.
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