According to the Department of the Interior, more than 100 species of fish and wildlife may presently be threatened with extinction within the United States. The recently concluded Convention to Control International Trade in Endangered Species of Wild Flora and Fauna (ELR 40336) listed 375 species of animals as imminently threatened with extinction throughout the world, and another 239 species of animals as not yet threatened with extinction but requiring additional controls over trade in them.

The threat to animals may arise from a variety of sources—pollution, destruction of habitat, and the pressures of trade. For the most part, federal legislative attention in recent years has concentrated upon commercial exploitation in an attempt to reduce or eliminate the financial incentives to trading in endangered species.