Several large airlines declared that they would no longer be allowing animal trophies to be transported on their planes. This is a great step by the airlines in discouraging big game hunters from paying tens of thousands of dollars to hunt threatened and endangered species.
The United States can do one better, we can create a US Customs law that prohibits trophies from entering the US at all. Currently customs allows threatened and endangered species trophies to enter the country as long as the hunters show permits for their hunts and obtain a CITES permit.
Many of the animals allowed to be taken as trophies by these permits are threatened and close to extinction, and we should discourage this hunt trade by banning endangered and threatened species hunt trophies from entering the US.