Nutria are large semi-aquatic rodents which are native to South America. They look like a beaver or muskrat when swimming and have nicknames like Swamp Beaver, Argentine Beaver and American Beaver. Nutria can grow to over 2 feet long and weigh over 20 lbs. Males are typically larger then females and like beaver, nutria have large incisors which tend to be yellow-orange to orange-red. Nutria are mostly brown in color, have short legs and commonly are mistaken to be a very large rat!
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NUTRIA BIOLOGY ^
Nutria have webbed hind feet which make swimming easier for them. They also have eyes, ears and noses which are set high on their head enabling them to hold these receptors out of the water when moving through water. Their mouth and nostrils have valves which close tight when submerged which helps them stay under water longer and more efficiently.
Nutria can live over 20 years but the average wild life span is more like 3-5 years. They have many predators including alligators, eagles, garfish, turtles and other carnivorous animals. Nutria are able to reproduce year round and reach sexual maturity in about 4 months. Litters average 6 young and the babies can eat and feed very quickly. They are able to suckle on land as well as in the water and will be weaned in about 2 months. For this reason they can become a problem quickly once active in any area.
NUTRIA HISTORY ^
Nutria were originally located in South America living in country sides close to the equator. However, they were introduced to many other continents over the years and have now established themselves in many different countries. These feral populations are largely wild though some farming of nutria still exists. Nutria were originally relocated with the intent of using their fur. Later on, it was thought they could help control undesirable weeds and plant growth around wet lands and other wild areas. Throughout the 1940’s and 1950’s, nutria were trans-located to many states in America. In the end, it was learned that the relocation of nutria created a lot more problems then benefits.
Currently found in states like Oregon, Washington, Texas, Louisiana, Florida and Georgia, their range now includes many inland staes like Oklahoma and several states along the great lake region. Currently established in over 20 states, nutria are here to stay.
NUTRIA PROBLEMS ^
At this point in time, nutria are mostly viewed as an undesirable pest. They eat a lot of just about anything and have become a problem for many reasons.
NUTRIA LOVE VEGETABLE GARDENS ^
They love sugar cane, rice, corn, milo, alfalfa, wheat, barley, oats, peanuts and most any vegetable. Since they are largely nocturnal, nutria can easily be mistaken for wild pig, raccoon or some other animal. Weekend gardeners and farmers alike are all targets of their veracious appetites. Nutria need to eat about 25% of their bodyweight daily. This is more then most any other animal its’ size and such a daily intake can put a stress on local plant life. When the low wetland vegetation is not able to support local herds, they will regularly forage to farms and urban areas searching for the most accessible meal available.
NUTRIA WILL DAMAGE THE LANDSCAPE
Nutria also cause a lot of damage due to their burrowing and digging. They commonly undermine levees, water pipes and other water management construction leading to floods and excessive water flow. Since they love to swim and like to have direct access to water, they try to reside around any type of drainage ditch, water holding pond, retention lake or other type of water impoundment. They will readily dig and burrow nest dens and living quarters which serve to disrupt and cause major problems with either water flow and/or storage.
Nutria also seem to like docks and wharves which utilize styrofoam for keeping them afloat. Like muskrat and beaver, nutria will burrow through this styrofoam causing it to sink and float unevenly. This damage will lead to constant maintenance and reconstruction of destroyed styrofoam. Furthermore, they will burrow alongside and adjacent to any building so marinas are particularly attractive to most nutria. Such environments provide both water harborage and land dwellings.
Other damage done by nutria include tree girdling, structure girdling when the structure is made of wood, sod and other turf destruction when dug up along with small plants being trampled or grazed to the ground. Nutria will readily girdle most any fruit, nut or shade tree. This behavior will lead to tree loss. Homes, sheds and other structures with raw wood like that commonly used on decks will attract nutria as well. They will girdle and gnaw any wood can reach. Sod which is fertile with either healthy roots or grub populations will readily attract nutria. They will dig up and overturn the grass and other landscaping in an effort to gain access to the food below. Once finished here, they will move to the flower beds or small garden if available. For this reason they have become a big nuisance in many subdivisions and other residential neighborhoods.
Since nutria are common where muskrat and beaver reside, they are often times overlooked as the animal responsible for local activity or damage. There are key identifying features of nutria damage which can help tell them apart from muskrat, beaver or something else. First, their burrows, crawl outs, drag lines and trails will show foot prints that have 4 webbed toes on the hind foot. It is also quite common to see a drag mark left by its tail since theirs is long and thin.
Nutria have large droppings which are cylindrical in shape and measure about 2 inches long and 1/2 inch wide. These will almost always be black or dark green. These droppings have parallel grooves along their entire length and are quite consistent from animal to animal.
Thirdly, trees which have been girdled by nutria will not bare any tooth marks yet the bark will be peeled away almost as if a giant potato peeler was used. Since they eat entire plants, no tell tale evidence of their targeted food is generally left behind as a clue. However, they will leave footprints when damage is done on land. Conversely, damage done to water grown crops are less likely to have this tell tale evidence left behind. These areas will require close observation to tell just what animal is responsible.
Like muskrat, nutria will eat most of the plant so inspecting the local shoreline will probably help identify just which animal is actively grazing. Since muskrat, rats and nutria all require different methods of control, it is imperative that the right animal is being targeted. And don’t expect to see all possible culprits during the day. Muskrat might be active during early morning or late evening hours while the sun is still out but nutria and rats are mostly nocturnal.
Of course, either will become active during the day if local food supplies are low and daytime foraging is needed to get their daily intake of food. But don’t wait around for this to happen. In most cases they will be active when people are not around. Once you know you have nutria active on any property, it is best to take a pro-active stance and try to minimize the herd as much as possible. Due to their ability to reproduce throughout the year and their ferocious non-stop eating, nutria will cause a lot of damage in a short period of time.
NUTRIA CONTROL ^
There are three main ways to control local nutria. Your choice should depend more on where the activity is most present and then once your options are clear for that given location, choose a tool or device which you will be comfortable using.
Since nutria have been active in the United States for over half a century, there has been a lot of ways people have tried to control local populations that have become a nuisance. Current methods include repellents, leghold traps, live catch cage traps and kill traps. The author will now discuss these options in greater detail making a point to list which type of device is best suited for any given problem.
NUTRIA REPELLENT SPRAY ^
If you have nutria active on property adjacent to yours and they are foraging onto your land in search of plants to eat or trees to girdle, you might consider applying some repellents. These are products which tend to work best when nutria have good food supplies and are not desperately seeking something to eat.
Nutria girdling tree bark can be stopped with 4-THE-BIRDS LIQUID. This product was originally created for use on tree limbs and window ledges where nuisance birds like to roost. Its essentially a non-drying glue which will readily stop any animal from messing with treated surfaces.
Make your application from the ground up to at least 3 feet high to protect desirable trees. Most applications will last 6-12 months during which time nutria will be forced to find some other tree to girdle.
Applications can be made with a paint brush or if you have a lot of trees to treat, use one of our PUMP SPRAYERS. 4-The-Birds Liquid is designed to be loose enough to spray and if you need to treat a lot of trees, using a sprayer will save a lot of time.
BEST SOUND REPELLER FOR NUTRIA ^
Another option which is highly effective and works immediately is our SOUND REPELLER. By default, this device sends out ultra sound sounds nutria do not like. They will avoid the protected area so units can protect trees or garden plants but can also chase away unwanted nutria from the yard.
Our unit will protect up to 5,000 sq/ft, can be configured to operate at night only, day only or around the clock. It can be powered by 4 “C” cell batteries or by AC power using the included power supply.
For nutria, the best setting is to have the unit set to go off at “night”, for the trigger to be activated by “motion” and to dial up the motion detector to 30. This means the unit will activate when animals get within 40 feet of the sensor.
When activated, it will send out an ultra sound nutria find disturbing but it will also flash its light bar which is scary to them.
There is an optional “audible” sound which should be used for nutria too. Set this to at least “40 db” but higher if possible. It can get super loud and this audible sound will also spook nutria so use it when possible.
For easy installation, MOUNTING BLOCKS are handy. They can accept 1 or 2 repellers (picture to the right) and have a 1/2″ hole on their bottom so they will easily fit over a 1/2″ piece of rebar or any other wood or plastic stake. Ultra Sound Repellers will work fine by themselves as long as you have a good place to set them up. But we highly recommend getting the Units with Mounting Blocks in the kits we offer. Mounting Blocks allow you to place units anywhere and they will save time too.