Ondatra zibethicus


Photo credit: ©Alan D. Wilson
Ondatra zibethicus  
Common Names:
  • Muskrat

  • It lives in inland surface water habitats, mires, bogs, fens, heath, scrub, and tundra.

  • The muskrat is a large, brown, stocky rodent, and has a hairless tail.

Origin and Worldwide Distribution:
  • The North American species was originally introduced for fur farming in the early 1900s but has since escaped or been deliberately released into the wild.
  • It is currently established Austria, Belgium, Bulgaria, Croatia, Czech Republic, Estonia, Finland, France, Germany, Hungary, Italy, Latvia, Lithuania, Luxembourg, Netherlands, Poland, Romania, Spain, Sweden, China, Japan, Kazakhstan, Kyrgyzstan, Mongolia and Uzbekistan.
  • In the 1930s, it was successfully eradicated in Ireland and the United Kingdom.

Potential or Known Impacts:
  • Muskrats are a fast growing, gregarious species, with a high reproductive potential and a nomadic lifestyle, which makes them highly adaptable to different freshwater environments.
  • They change the composition and structure of native wetland vegetation, which in turn affects aquatic invertebrates and destroys fish nurseries.
  • Their burrowing activities degrade river banks and affect river flow.
  • They can also exert a strong predation pressure on endangered species such as the freshwater pearl mussel.
  • The economic impact of the muskrat is no less significant. It causes extensive damage to crops, irrigation systems, roads, railroads, dams and flood protection systems.

How could it get here?
  • Originally from fur-farming but escaped.

Is it found in Northern Ireland?
  • It hasn't been recorded in Northern Ireland.

Methods for Prevention:
  • Union level action includes a ban on keeping and selling, a rapid eradication of newly establishing populations and containment of the invasion, especially keeping them out of protected areas.
  • Report all sightings.

You can help by reporting any sightings: @ the Centre for Environmental Data & Recording (CEDaR) - Or via the iRecord App.
Current Legislative Position (Listed on 03 August 2017)
  • This species must not intentionally be brought into the Union; kept; bred; transported to, from or within the United Kingdom, unless for the transportation to facilities in the context of eradication; placed on the market; used or exchanged; permitted to reproduce, grown or cultivated; or released into the environment.
For further queries, you can contact the Invasive Non Native Species (INNS) Team in the Northern Ireland Environment Agency on 028 9056 9558 or Email:

Species Related Files:

Invasive Species Northern Ireland

Invasive Species Northern Ireland