A coalition of conservation groups filed a petition Tuesday to list the African lion (Panthera leo) as a protected species under the U.S. Endangered Species Act (ESA), citing the American appetite for sports hunting and lion products—such as lion-skin rugs—as major factors in the big cat's decline.

The petition was filed by the International Fund for Animal Welfare (IFAW), The Humane Society of the United States (HSUS), Humane Society International (HSI), Born Free USA, Born Free Foundation and Defenders of Wildlife.

"The king of the jungle is heading toward extinction, and yet Americans continue to kill lions for sport," Jeff Flocken, IFAW's Washington, D.C., office director, said in a prepared statement. "Our nation is responsible for importing over half of all lions brought home by trophy hunters each year. The African lion is in real trouble, and it is time for this senseless killing and unsustainable practice to stop."

Although lions are difficult to count, populations are estimated to have dropped nearly 50 percent in the past three decades, mainly due to unsustainable hunting. Other threats include habitat loss, disease, the bushmeat trade, use of lion parts in traditional African medicine, and retaliatory killings for livestock killed by lions. Current estimates range from 23,000 to 40,000 lions left in Africa, down from an estimated 75,800 in 1980.

According to the groups' petition (pdf), at least 5,663 wild lions were traded internationally for recreational trophy hunting purposes between 1998 and 2008, with 64 percent of those trophies being imported into the U.S.

"Because of their evolutionary and biological behaviors, trophy hunting is particularly bad for lions," Flocken said at a press conference on Tuesday. Among the cats, trophy hunters tend to target the large, visually striking male pack leaders. The death of a leader leaves a pack unstable, resulting in younger males fighting and often killing each other for dominance. The new top male often also ends up killing all of the pack's cubs to preserve his genetic dominance, and some females may die trying to protect their offspring. "The countries that allow hunting have the worst drops in lion populations," Flocken said.

Adding lions to the list of species protected by the ESA would create a ban on the import of hunting trophies. This would "hopefully reduce the threat to lions by eliminating the incentive of bringing back a trophy," Flocken said. Listing the species would also prohibit the sale of commercially traded lion parts such as skins, claws and skulls, which can sell for thousands of dollars each.

ESA protection would further help lions by raising awareness of their plight, said Bob Irvin, senior vice president for conservation programs at Defenders of Wildlife. "Without the Endangered Species Act, the very symbol of African wildlife could disappear forever," he said.

Americans are hardly the only factor pushing lions toward extinction. Africa's human population is growing quickly, especially in sub-Saharan Africa, where it could hit 1.75 billion by 2050. This puts enormous pressure on lions' habitat, which has already shrunk to less than a quarter of its historic range. It will also fuel further human–lion conflicts, with lions perceived as dangers to safety and prosperity, much the same way wolves are often seen in the U.S.

The U.S. Secretary of the Interior now has 90 days to assess whether listing lions under the ESA may be warranted, 12 months to decide whether to propose listing, and then another 12 months to make a final decision.

Asiatic lions (P. l. persica) are already protected under the ESA. Only about 400 of that particular subspecies remain the wild, all living in a single forest in India.

Photo via Wikimedia Commons