What is an Invasive Species?

It is a nonnative fish called the northern snakehead, which threatens to ruin the ecological balance of the entire Chesapeake Bay. It is a nonnative plant called Old World climbing fern, spreading like wildfire – at a rate of 18 acres every single day – wiping out native habitat in South Florida. It is a South American rodent called Nutria, which found itself in the middle of the marsh in coastal Maryland, and is eating its way out.

The term invasive species describes the set of harmful, nonnative plants, animals, and microorganisms found throughout the United States that are causing widespread damage to bird and wildlife habitat and cause billions of dollars of damage annually to crops, rangelands, and waterways. Many of America’s most imperiled birds are threatened by invasive species, including more than one-third of the birds on Audubon’s WatchList.

Invasive species have infested more than 100 million acres of the American landscape, and continue to spread across more than 3 million acres each year, an area equal to a strip of land two miles wide stretching from coast to coast. Scientists, academics, government experts, and industry leaders are recognizing invasive species as one of the most serious environmental threats of the 21st century.