For information on how to live with wildlife, visit these species pages:
Bats | Beaver | Birds | Black Bears | Cougars | Coyotes | Deer and Elk | Frogs | Nutria | Osprey | Owls | Raccoons | Snakes | Tree Squirrels | Turtles | Wolves | Young Wildlife
-Oregon Fish and Wildlife-
Nutria construct burrows in banks of rivers, sloughs, and ponds, sometimes causing considerable erosion. Burrowing is a commonly reported damage caused by nutria. Burrows can weaken roadbeds, stream banks, dams, and dikes, which may collapse when the soil is saturated by rain or high water. Rain action can wash out and enlarge collapsed burrows and compounds the damage.
Nutria depredation on crops is also well documented. Crops that have been damaged include corn, sugar and table beets, alfalfa, wheat, barley, oats, various melons, and a variety of vegetables from home gardens and truck farms. Nutria girdle fruit, nut, deciduous and coniferous forest trees, and ornamental shrubs. They dig up lawns when feeding on the tender roots and shoots of sod grasses.
At high densities and under certain adverse environmental conditions, foraging nutria can also significantly impact natural plant communities. Overutilization of emergent marsh plants can damage stands of desirable vegetation used by other wildlife. Nutria are aggressive competitors with the native muskrat which is smaller. Muskrats have been largely eliminated or greatly reduced where nutria have become established.
In Oregon, nutria are classified as unprotected Nongame Wildlife (OAR 635-044-0132). As unprotected wildlife nutria may be trapped (cannot be relocated) or shot. No license is needed for a landowner to control nutria on his/her own property. Most cities have restrictions on leg-hold trapping or the discharge of firearms within their city limits--live trapping is usually the main population control measure inside the city limits.
Since nutria are usually found in waterways, there is often an unlimited supply of replacement animals upstream and downstream from where the damage is occuring. Rapid immigration coupled with a high reproductive rate makes population control a "high effort" method of damage control and often ineffective. Exclusion is often the best long term solution to nutria damage. Most commonly used methods include:
- Low woven-wire fences (about 3 feet) with an apron buried at least 6 inches have been used effectively to exclude nutria from home gardens and lawns.
- Electric wire barriers have also been used to exclude nutria where vegetation can be controlled to keep it from shorting the wires. Usually one wire 6 inches off the ground will be effective.
- Welded-wire cylinders around individual plants are often used where only a few plants need to be protected.
- Sheet metal shields can be used to prevent gnawing damage to wooden structures or trees.
In creating dikes and drainage ditches it is often important to consider nutria damage and the maintenance that can be required. Nutria like steeply sloped banks next to relatively deep water for den sites. Dikes and drainage ditches designed with gradual slopes will be much less attractive as den sites and require much less if any nutria damage maintenance.
Crops and gardens located close to water will be more attractive to nutria than those further from water. If you have a choice of where to locate your garden, consider nutria damage. Natural vegetation buffers next to water bodies can provide feeding areas and reduce the attractiveness of vegetation further from the water.
Nutria are wary creatures and will try to escape when threatened. Loud noises, high-pressure water sprays, and other types of harassment have been used to scare nutria from lawns and golf courses. The success of this type of control is usually short-lived and problem animals soon return, consequently, hazing is usually not an effective control technique. Large aggressive dogs are often persistant and effective at 'hazing" nutria out of back yards. Small dogs are often intimidated by bold nutria.
No chemical repellents for nutria are currently registered.
Nutria are easily captured in live traps. Bait live traps with sweet potatoes or carrots and place them along active trails or wherever nutria or their sign are seen. A small amount of bait leading to the entrance of the live trap will increase capture success. When cornered or captured, nutria are aggressive and can inflict serious injury to pets and humans. Extreme care should be taken when handling captured nutria.