Injurious wildlife

Injurious wildlife is a U.S. federal designation under the statute 18 U.S.C. § 42 that prohibits the importation of injurious (invasive or otherwise harmful) wildlife species into the United States. That statute originated from a law passed in 1900, when U.S. Representative John Fletcher Lacey introduced a bill "to regulate the introduction of American or foreign birds or [mammals] in localities where they have not heretofore existed," and that law became known as the Lacey Act of 1900. Besides the injurious part of the law, another purpose in that same Act, and the one more often associated with Lacey's name, prohibited the interstate transport of game killed in violation of local laws (now 16 U.S.C. §§ 3371–3378).

Currently, injurious wildlife species are wild mammals, wild birds, fishes, amphibians, reptiles, mollusks, and crustaceans found through regulation or Congressional action to be injurious to the interests of human beings, agriculture, horticulture, forestry, or to wildlife or wildlife resources of the United States. The current injurious wildlife law, implemented by the U.S. Fish and Wildlife Service, prohibits the importation of certain wildlife species into the United States, any territory of the United States, the District of Columbia, the Commonwealth of Puerto Rico, or any possession of the United States, or any shipment between the continental United States, the District of Columbia, Hawaii, the Commonwealth of Puerto Rico, or any possession of the United States. Exceptions may be made with a permit issued for importation and some interstate shipment for zoological, educational, medical, and scientific purposes. The penalty for a violation of 18 U.S.C. § 42 is up to 6 months in prison and a $5,000 fine for an individual or a $10,000 fine for an organization. The law does not address export, interstate transport within the continental United States, intrastate transport, sale, or possession.

Preventing the importation of injurious wildlife is important because invasive species can prey on endangered and other native species, devour crops and native plants, clog water intake pipes at power plants, short out power lines, degrade ecosystems, spread diseases. and cause other harms. Economic costs to the public of invasions are difficult to measure but have been reported for the United States from 1960 to 2020 as totaling $1.22 trillion when conservatively considering only observed, highly reliable cost estimates.