What Ontario is doing

To prevent this unwanted invader from coming into the province, Ontario has regulated nutria (Myocastor coypus) as a prohibited invasive species under the Invasive Species Act.

Learn about the Invasive Species Act and regulations.

Background

Nutria (Myocastor coypus), also known as coypu, are large semi-aquatic rodents originally from South America. They were brought to North America and Europe for fur farming in the early 20th century. They have since become invasive in many regions due to escapes and releases from fur farms. Nutria have webbed hind feet and distinctive orange incisors. They are nocturnal but will feed during the day if food is scarce.

When introduced to new areas, nutria's adaptable nature, prolific breeding and lack of natural predators have led to rapid population growth and ecological imbalances. They feed extensively on vegetation and their burrowing damages wetlands and riverbanks, disrupting local ecosystems and reducing biodiversity. While valued for their fur in the past, the decline in the fur trade has contributed to their release into the wild, where they now pose significant environmental and economic challenges in areas they have established.

Range

Nutria are native to South America with known populations in southern Brazil, Paraguay, Uruguay, Chile and Argentina.

Nutria have spread far beyond their native range due to human activity, particularly the fur trade.

Their introduced range includes Asia, Africa, Europe, and parts of North America. In the United States, nutria have established populations and have been found in 22 states. They are most abundant in coastal states including Louisiana, Oregon and Washington. In Canada, nutria were originally introduced into several provinces for the purposes of captive breeding on fur farms. The only Canadian province with reports of current sightings is British Columbia.

In Ontario, there are no known populations of nutria in the wild. The last documented individuals to have been sighted and trapped in the wild were 4 nutria recorded in between 1953 and 1955, near Thunder Bay. 

View an up to date distribution map of Nutria.

Impacts

Nutria can significantly alter ecosystems once they become established. The burrowing and foraging behaviour of nutria can impact agriculture areas, including causing crop damage, weakening irrigation structures and damaging drainage systems and water-retaining levees. They can also cause damage to waterways and infrastructure, increasing the risk of flooding and erosion which in turn, pose health and safety risks to humans, livestock and wildlife.

Nutria are known reservoirs for a variety of pathogens and parasites that can be transmitted to humans, pets and livestock. Nutria also compete with native wildlife for food and habitat and reduce biodiversity in invaded areas.

How to identify

  • Nutria are large rodents, typically weighing 5 to 10 kilograms.
  • They have dense brown fur, large orange incisors (front teeth) and a long, round tail.
  • Their hind feet are webbed, aiding in swimming.
  • Nutria are often confused with the native beaver or muskrats, but are distinguishable by their round tails and size. Nutria are smaller than a beaver and larger than a muskrat.

What you need to know

  • Learn how to identify nutria and how to prevent the introduction or spread of this animal in Ontario.
  • It is against the law to import, possess, deposit, release, transport, breed or grow, buy, sell, lease or trade nutria in Ontario.
  • Never release animals into the natural environment. This can unintentionally start an invasion that negatively affects Ontario’s native species.

Reporting illegal activity

If you have any information about the illegal importation, distribution, or sale of nutria, report it immediately to either:

If you’ve seen nutria or another invasive species in the wild, please: