Nutria

Nutria is a herbivore animal. Nutria is semi-aquatic rodent animals. It is also known as Coypu. It is classified as the only member of the family Myocastoridae. Myocastor is now included in the family Echimyidae, the spiny rat. Nutrias live in caves near water and feed on the stems of river plants. It was originally native to subtropical and temperate South America, after which it was introduced to North America, Europe, Asia, and Africa by fur producers. Although it is still hunted and trapped for its fur in some areas, its destructive digging and feeding habits often cause it to come into conflict with humans and it is considered an invasive species.

The Appearance of Nutria Animal

Nutrias resemble a very large mouse or beaver with a very small tail. Adults typically weigh 9 to 20 pounds and have a body length of 16 to 24 inches, and a 12 to 18 inches tall. Nutria can weigh up to 16 to 17 kg, but the average adult weight is usually 4 to 7 kilograms. They have rough, dark brown fur with a soft, dense gray underneath, and are also called Coypu. The three distinguishing features are white plates on the muzzle, webbed hind legs, and large bright orange-yellow incisors. The female nutria's nipples are high on her flanks to allow her cubs to eat when the female is in the water. Nutria is often mistaken for the muskrat. It is another widely distributed semi-aquatic rodent that occupies the same wetland habitat. However, muskrats are smaller, can tolerate colder climates better, and have a horizontally flat tail to help swim, while nutria has round tails. It may also be mistaken for a small beaver because the anatomy of beaver and nutria are very similar. However, unlike the round tail of a nutria, the tail of a beaver is a flat paddle. 

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Rodents

Rodents are mammals of the order Rodentia. They are characterized by a pair of continuously growing incisors in each of the upper and lower jaws. About 40% of mammalian species are rodents. They are native to all major landmasses except New Zealand, Antarctica, and a few marine islands, although they were subsequently introduced into most of this landmass by human activities. The ecology and lifestyle of rodents are extremely diverse and can be found in almost all terrestrial habitats, including man-made environments. The species can be arboreal, gliding, or semi-aquatic. However, all rodents have several morphological characteristics in common, including only a constantly growing upper and lower pair of incisors. The best-known rodents include mice, rats, squirrels, marmots, porcupines, beavers, guinea pigs, and hamsters. The incisors of rabbits, hares, and pikas also continue to grow. They were once included, but are now considered a separate order, Lagomorpha. However, Rodentia and Lagomorpha are sister groups, share a common ancestor and form a branch of Glires. 

Most rodents are small animals with strong physiques, short limbs, and long tails. They use their sharp front teeth to chew, dig caves, and protect themselves. Most people eat seeds or other plant materials, but some people have a more varied diet. They are often social animals and many species live in societies with complex ways of communicating with each other. Mating between rodents can range from monogamy to polygamy to promiscuity. Many puppies are underdeveloped and in old age, while others are precocious at birth.

Life History of Nutria Animal

Nutrias can live up to six years in captivity, but individuals rarely live longer than three years. According to a study, 80% of nutria die within the first year, and less than 15% of them die. Male nutria reaches sexual maturity at four months, and females reach sexual maturity at three months. However, puberty for both is prolonged, up to 9 months. Once a female becomes pregnant, the gestation period is 130 days and can give birth to as few as 1 or as many as 13 cubs. They usually cover the nursery with soft grass and rushes. Baby nutria is precocious and is born with their fur and eyes open. They can eat plants with their parents within a few hours after birth. A female nutria can conceive again on the second day after giving birth. If the procedure is correct, a woman can conceive three times a year. The newborn nutria nursed for seven to eight weeks before leaving their mother. 

Habitat and Feeding of Nutria Animal

In addition to rapid reproduction, nutrias consume a lot of plants. A person consumes about 25% of his body weight every day and eats throughout the year. As one of the largest rodents in the world, a healthy, mature nutria weighs an average of 5 kilograms but can weigh up to 10 kilograms. They eat the base of the stems of ground plants and often dig up organic soil to find roots and rhizomes to eat. The places where they eat, where most of the biomass has been removed above and below ground, created patches in the environment, which in turn changed the habitats of other animals and humans that depended on the swamp. Nutria is most commonly found in freshwater marshes, but they also live in brackish marshes and rarely in marshes. They either build their own caves or occupy caves abandoned by beavers, muskrats, or other animals. They can also build floating rafts with vegetation. 

Global Distribution of Nutria Rodent 

The nutria rodent is native to the subtropical and temperate regions of South America and has since been introduced to North America, Europe, Asia, and Africa by fur farmers. With continuous cold or mild winters, nutria's distribution outside of South America tends to shrink or expand. In the cold winter, nutria often suffers from tail frostbite, leading to infection or death. As a result, nutria populations have often declined, and local or regional extinctions even occurred in Scandinavian countries and US states such as Idaho, Montana, and Nebraska in the 1980s. In mild winters, their distribution tends to expand to the north. For example, in recent years, Washington and Oregon, and Delaware have expanded their reach. According to the US Geological Survey, the nutria was first introduced to the United States in California in 1899. They were first brought to Louisiana for the fur industry in the early 1930s and controlled the population, or the number was small, due to pressure from the fur traders. The first record of the free spread of nutrias from the fence to the Louisiana wetlands was in the early 1940s. A hurricane struck the Louisiana coast. The storm destroyed the fence and allowed the nutria to escape into the wild. According to the Louisiana Department of Wildlife and Fisheries, the nutrias were also transplanted from Port Arthur, Texas to the Mississippi River in 1941, and then spread due to a hurricane later that year.

Damage to Wetlands 

Nutria's herbivory nature severely reduces the overall biomass of wetlands and may cause wetlands to turn into open water. Unlike other common disturbances in swamps, such as fires and tropical storms, which occur once or several times a year, nutrias eat throughout the year, so their impact on the swamp is constant. In addition, nutria is more destructive in winter than in the growing season, which is mainly due to the scarcity of aerial vegetation. When nutrias are looking for food, they will dig root nets and rhizomes to find food. Although nutrias are the most common herbivores in the salt marshes of Louisiana, they are not the only herbivores. Wild boars, also known as warthogs, swamp rabbits, and muskrats are less common, but the number of wild boars in the Louisiana wetlands is increasing. In plots open to nutria grazing, vegetation was found to be 40% less than in plots where fences were used to prevent nutrias. This number seems to be negligible. In fact, herbivores themselves are not a serious cause of land loss, but when herbivores are combined with other disturbances, such as fires, removal of single vegetation, or removal of dual vegetation to simulate tropical storms, The impact of disturbance on vegetation has greatly expanded. In essence, this means adding different factors together, and the result is a reduction in overall vegetation. Fertilizing the open space did not promote plant growth, on the contrary, the nutrias forage more food in the fertilized area. Increasing the fertilizer input to the marshland will only increase the biomass of the nutria, not the predicted vegetation, so it is not recommended to increase the nutrient input. 

Damage to Land

The wetlands are valuable resources in terms of economy and environment. For example, the U.S. Fish and Wildlife Service determined that wetlands account for only 5% of the land area of ​​48 adjacent areas in the United States, but support 31% of the country's plant species. These highly biologically diverse systems provide resources, shelter, nesting sites, and habitats for various wildlife. Human users also get many benefits from wetlands, such as cleaner water, storm surge protection, oil, and gas resources especially on the Gulf Coast, reduced flooding, and reduced chemical and biological waste, to name a few. In Louisiana, the rapid disappearance of wetlands is due to a variety of reasons; the area lost per hour in this state is estimated to be the size of a football field. The problem became so serious that the Sheriff of Jefferson Parish Harry Lee used SWAT snipers against animals. In 1998, the Louisiana Department of Wildlife and Fisheries (LDWF) conducted the first survey of the entire coastline of Louisiana. The survey was funded by the Coastal Wetlands Planning, Protection and Restoration Act, titled " Wetland and Wetland Demonstration Program". Nutria Harvest assesses the condition of the swamp. The study showed that the destruction of wetlands by herbivores totalled approximately 36,000 hectares through aerial cross-sectional surveys. The following year, LDWF conducted the same study and found that the area destroyed by herbivores increased to approximately 42,000 hectares. The LDWF has determined that wetlands affected by nutria have decreased from the estimated low of 32,000 hectares of Louisiana wetlands in 2002-2003 to approximately 2,548 hectares during the period 2010-2011. LDWF emphasized that if the nutria population is not effectively and sustainably controlled, coastal wetland restoration projects will be severely hampered. 

Control Strategy in the United Kingdom

In the United Kingdom, nutria escaped from fur farms. As early as 1932, it was reported in the wild. Between 1943 and 1944, Eastern England tried to control nutria three times, but they were all unsuccessful. The population and distribution of nutria increased, causing damage to agriculture in the 1950s. In the 1960s, grants were provided to rabbit compensation associations including nutria. This control allowed the removal of 97,000 nutrias in 1961 and 1962. From 1962 to 1965, 12 hunters were hired to kill as many nutrias as possible near Lake Norfolk. The event used live traps, allowing non-target species to be released by shooting any captured nutrias. Along with the cold winter of 1962 to 1963, nearly 40,500 nutrias disappeared from the population. Although the number of nutrias declined significantly after the end of the 1962-1965 campaign, it was not until another eradication campaign began in 1981 that the campaign succeeded in eradicating nutrias in the UK. The capture area is divided into 8 sectors, and there is no unchecked area. All 24 hunters received rewards for completing 10 years ahead of schedule. In 1989, it was assumed that nutria had been eradicated because only 3 males were found between 1987 and 1989. 

Control Strategy in Ireland 

Nutria was first discovered in the wild in Ireland in 2010. Nutria escaped from a petting farm in Cork in 2015 and began breeding in the suburbs of the city. In 2017, 10 animals were trapped in the Curraheen River, but the rodents continued to spread and reached Dublin through the Royal Canal in 2019. Animals were found along the Marquill River in 2015. The National Biodiversity Data Center issued a species alert in 2017, stating that the nutria has the potential to become a highly impacted invasive species in Ireland. This species is listed as one of the 100 most severe invasive species in Europe.

Commercial and Environmental Uses 

Due to overfishing, nutria fur farms became locally extinct in the late 19th and early 20th centuries. The first farm was in Argentina, then Europe, North America, and Asia. These farms generally do not have successful long-term investments, and the nutria that is farmed is generally released or flee when the operation becomes unprofitable. The first attempt at raising nutrias was in France in the early 1880s, but it was unsuccessful. In the 1920s, the first extensive and efficient nutria farms were located in South America. South American farms were very successful and led to the development of similar farms in North America and Europe. Nutrias from these farms often escape or are deliberately released into the wild to provide prey or remove aquatic vegetation. Nutrias were introduced to the Louisiana ecosystem in the 1930s when they escaped from imported fur farms from South America. In 1933, at least one Louisiana nutria breeder released nutria into the wild and was subsequently released by E. A. McIlhenny, who released the entire population on Avery Island in 1945. In 1940, some nutria escaped in a hurricane and quickly settled in coastal marshes, inland marshes, and other wetland areas. Beginning in Louisiana, nutria has spread to the southern United States, causing severe damage to the salt marshes. After the demand for nutria skins declined, nutrias have become pests in many areas, destroying aquatic vegetation, swamps, and irrigation systems, chewing on artificial objects such as tires and wood panelling from Louisiana houses, eroding river banks and native animals. Since the 1980s, the damage in Louisiana has been severe enough to be worthy of legislative attention.