Ondatra zibethicus


  • Photo credit: ©Alan D. Wilson

  • Ondatra zibethicus  

  • Common Names: Muskrat

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

  • Description: 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 did it/could it get here? Originally from fur-farming but escaped.
  • Is it found in Ireland or Northern Ireland? Although it was previously eradicated and not deemed established in Ireland, this species has been recorded in 2015 in Co Cork. It hasn't been recorded in Northern Ireland. More information can be found at NBDC.
Static Distribution Map as of December 2019 - Courtesy of CEDaR
  • 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

  • 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 Non Native Invasive Species Team in the Northern Ireland Environment Agency on 028 9056 9558.
Invasive Species Ireland

Invasive Species Ireland