The best way to prevent wildlife invasions in the United States is to stop their introduction into the country, and that is why injurious wildlife listing is so important. More than 800 wildlife species from around the world are listed as injurious, including mammals, birds, fishes, salamanders, reptiles, mollusks, and crustaceans (50 CFR 16). Most species were listed for their traits of invasiveness. Some were listed because they can be hosts of viruses, bacteria, or parasites that can be transmitted to other wildlife species or to humans. Of the more than 300 species listed for potential invasiveness, 94 percent were listed were listed before they were introduced into the United States, and those species have not subsequently become invasive, making the injurious wildlife law highly effective. Some species have been listed after they became invasive, such as the
Burmese python in Florida, which is causing dramatic declines of wildlife in the
Everglades. Although Burmese pythons were listed as injurious in 2012, after they became invasive, the U.S. Fish and Wildlife Service preemptively banned the importation of 7 other species of large constrictor snakes from other countries before they could become invasive. These include the two largest snakes in the world, the
reticulated python and the
green anaconda. Other species, such as the
brushtail possum, were already highly invasive in
New Zealand but not invasive in the United States when the U.S. Fish and Wildlife Service added it to the injurious list in 2002, and it has not established in the wild in the United States. The most recent major amendments to the law were in 1960, leaving a need for modernizing to respond to the growing global trade in wildlife species. For example, the only invertebrates that can be listed as injurious are
mollusk and crustacean species, leaving insects, jellyfish, and all other types of land and water invertebrates ineligible for listing. Some efforts have been made in Congress, such as the bipartisan "Invasive Fish and Wildlife Prevention Act". Those bills and similar ones did not pass the Legislature but suggest ways to address the limitations of the current invasion law. ==See also==