Trophy hunters prize the regal lion above virtually all other animals, but shooting lions without overhunting is tricky. Excessive trophy hunting could open the door for too many young males to invade prides and kill all the cubs, causing a population decline. On the other hand, income from trophy hunting helps sustain African game reserves, which might otherwise be converted to small-scale agriculture. In an effort to reconcile the needs of lions and of people who manage their populations, University of Minnesota researchers simulated hunting using demographic data from actual lion populations. The study indicates that if hunting is limited to male lions age five and older, populations of any size can be sustained without bag limits. The study, which also describes a means of estimating lion ages in the field, will be published online Sunday, Feb. 22, in the journal Nature.
All African hunting reserves impose bag limits, or quotas, but quotas are supposed to be based on the size of an animal population. Lions, however, are hard to count. Using long-term data on lion behavior, mortality, reproduction and other characteristics gathered by University of Minnesota lion researcher Craig Packer, a team led by graduate student Karyl Whitman created a computer model to predict the effects of different hunting regimes on lion populations over a period of 50 years.
"This is one of very few studies on how hunting changes [lion] behavior and how we can manage hunting to improve its sustainability," said Whitman. "Weve put forward two simple rules: You can sustainably shoot male lions without limits as long as theyre 5 or older, and you can age lions before shooting them." As cubs, lions have noses that are soft pink to gray at the tips. After a lion reaches age 3, the nose starts to blacken in splotches. If a lions nose tip is more than 50 percent black, the lion is probably at least 5 years old, the researchers said.
Deane Morrison | EurekAlert!
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