Delta Air Lines has banned shipments of lion, leopard, elephant, rhinoceros and buffalo trophies as freight.

Until Monday, Delta had accepted hunting trophies typically the preserved body or head of an animal killed by a hunter — if customers provided appropriate documentation to U.S. customs officials and if the animal in question was not a protected species.

The move comes amid an outcry over the killing of the well-known lion Cecil by an American hunter, Minneapolis dentist Walter Palmer, after the lion was lured out of a Zimbabwe wildlife reserve.

Delta, in a short statement about its shift on the issue, said Monday it will also review policies for accepting other hunting trophies with government agencies and organizations supporting legal shipments.

The new ban also comes after a petition launched earlier this year called for the airline to stop transporting exotic animal hunting trophies. The petition on change.org has gained more than 394,000 supporters.

Chris Green, legislative director for the Animal Legal Defense Fund, said in his petition that he is a Diamond Medallion frequent flier on Delta. He said he started the petition last spring after South African Airways announced a policy refusing to transport exotic animal hunting trophies.

Delta is the only U.S. airline to serve South Africa directly.

Other foreign carriers have since joined in announcing bans, and while some have more extensive restrictions on hunting trophy shipments, Delta’s move “is a massive step forward,” Green said.

Asked about its policy, Sandy Springs-based shipping giant UPS said in an email: “There are many items shipped in international commerce that may spark controversy. The views on what is appropriate for shipment are as varied as the audiences that hold these views.”

“We avoid making judgments on the appropriateness of the contents,” the statement continued. “All shipments must comply with all laws, including any relevant documentation from the shipper required in the origin and destination location of the shipments.”