U.S. Fish & Wildlife Service

Invasive Species


Learn More About Invasive Species

National Wildlife Refuge System

An FWS employee standing next to a volunteer using a handheld device to map invasive species.
Mapping Invasive Plants at Cache River NWR
Credit: USFWS

 The Fish and Wildlife Service manages more than 561 refuges, encompassing more than 150 million acres of wildlife habitat, within the National Wildlife Refuge System (NWRS). According to Fiscal Year 2013 data, more than 2.4 million acres of the Refuge System are impacted by  invasive plants. In addition, there are approximately 1,715 invasive animal populations residing on refuge lands.

What’s the Problem?

Invasive species are the most frequently mentioned threat in the NWRS Threats and Conflicts database. Instead of focusing on native habitat protection or enhancement, refuge management operations are becoming more frequently tied to battling invasive species. Federally listed threatened and endangered species are also experiencing more direct impacts from exotic invasions.

What is the Refuge System Doing About It?

Ever since the National Strategy for Management of Invasive Species (324 KB PDF), was established in 2003, the Refuge System has been taking a variety of innovative and aggressive steps to deal with burgeoning invasive species issues.

An FWS employee standing next to a volunteer using a handheld device to map invasive species.
Volunteers from Friends of Alaska National Wildlife Refuges celebrate a successful weed pull.
Credit: Jerry D. McDonnell

Who’s Helping? Volunteers!

The NWRS is leading Department of the Interior natural resource agencies in using volunteer labor to manage, map and monitor invasive plant infestations on refuges across the country. Between 2004 and 2009, approximately 5,600 volunteers spent over 86,000 hours working with refuge staff to manage invasives and restore native plants on more than 415,000 acres of refuge land.

We invite you to use our award-winning online training program for volunteers, Volunteers and Invasive Plants: Learning and Lending a Hand. Developed in collaboration with the Center for Invasive Plant Management, this training engages refuge volunteers and the general public in invasive plant issues and management with science-based, introductory information.

The five self-study modules cover the role of volunteers, the invasion process and tips for community leaders offering presentations on the topic. Each module contains a quiz and web-based resources that enable learners to explore topics more thoroughly.

Professional Training

We have also developed an online training program for invasive species professionals - Managing Invasive Plants: Concepts, Principles, and Practices. This program was developed especially for staff of the National Wildlife Refuge System in collaboration with the Center for Invasive Plant Management.

This training focuses on planning and assessing, as well as specific IPM strategies, such as biocontrol, chemical, mechanical, and prescribed grazing and burning. The course is recommended as a supplement to the hands-on course, "Field Techniques for Invasive Plant Management," held annually at the National Conservation Training Center in Shepherdstown, West Virginia.

An FWS employee standing next to a volunteer using a handheld device to map invasive species.
Credit: USFWS

Strike Teams

Invasive Species Strike Teams are working to protect refuges in key geographic locations, such as

  • the Florida Everglades,
  • the Southwest lower Colorado river basin,
  • the Upper Missouri/Yellowstone/Upper Columbia River (MOYOCO) watershed,
  • North Dakota (prairie pothole region), and
  • the Hawaiian and Pacific Islands.

These teams respond rapidly to new infestations and offer technical expertise to refuges The NWRS hopes to implement more teams in the future.

Invasive Species Strike Teams Update 2010 (1.5 MB PDF)


An FWS employee standing next to a volunteer using a handheld device to map invasive species.
Prescribed burn at Balcones Canyon National Wildlife Refuge, TX
Credit: USFWS

Fire Management

Fire and invasive plants are often intimately linked. Fire management activities can create ideal opportunities for invasions by nonnative plants, potentially undermining the benefits of fire management actions.

Brochure cover - a blazing fire with a firefighter in the foreground.

The Fire Management and Invasive Plants: A Handbook helps both fire and invasive plant managers determine the best approach. (1.3 MB PDF)


Refuge Planning

Finally, the NWRS is encouraging refuges all across the nation, whether they currently have major invasive species issues or not, to take invasives into account in all their planning through the Comprehensive Conservation Plan process and through implementing Hazard Analysis and Critical Control Point planning in their day-to-day operations.