Longtime environmental activist Leonardo DiCaprio, who is also on the board of the World Wildlife Fund, is planning to run a global campaign in conjunction with the WWF to ban all ivory trade in Thailand. They’re asking for signatures on a petition for Prime Minister Yingluck Shinawatra to ban the trade and save African and Asian elephants from illegal hunts. Leo has expressed his concerns about how elephants and other species are threatened because of the high demand for their parts. Thai law prohibits sales of African tusks, but it is legal to sell ivory from domestic elephants. The loophole in this allows large quantities of African ivory to be illegally imported to Thailand each year. DiCaprio was quoted as saying in a statement released by the WWF, “Whole populations are at risk of being wiped out if we don’t take immediate action to shut down this illicit trade.”