Sunday, January 20, 2008

Nutia


I have been looking into a legal way have getting animals for their hides and also for food. I was picking up road kill awhile back and was able to make some nice projects with them. However, I am going to teach others about skinning and preparing an animal using real animals I would like to do it legally. I did a search on nutria and found out alot of information. It is legal to live trap nutria without any permits or fees. There are no restrictions to how many can be killed. This is because they are not native to North America and are a real problem. Here is all the information you will need. I would really like to hear from anyone about what they think about this and/or if anyone gets a trap and does it. I am very excited to get started. I already have projects in my head of what to make.




The nutria is a member of the myocastoridae family. The word "nutria" means "otter" in Spanish. Nutria are native to portions of Argentina, Bolivia, Chile, and Uruguay and are not indigenous to the State of Oregon. The South American nutria became a subject of interest in the fur industry back in the early 1930s when their large size and high reproductive potential held promise for fur farming businesses in North America. Many hopeful investors started small captive colonies in many locations in the United States, Canada, and many European countries. Many of these farms, however, did not succeed and the animals either escaped or were intentionally released to the wild, which resulted in the wild populations present today. Wild nutria were first reported in Oregon during the 1930s.
Identification
At first glance, nutria may be misidentified as a beaver or muskrat. A nutria is smaller than a beaver but larger than a muskrat; unlike beavers or muskrats, however, it has a round, slightly haired tail. Nutria have large incisors that are yellow to orange-red on the outer surface. The dense grayish underfur is overlaid by long, glossy guard hairs that vary in color from dark brown to yellowish brown. The guard hairs are long and coarse on the back and finer on the side and the belly. The forelegs are small compared with its body size. The forepaws have five toes; four are clawed and the fifth is reduced in size. The claws are used to groom and to excavate roots, rhizomes, and burrows, and are used in feeding. The hind foot consists of four webbed, strongly clawed toes and one unwebbed toe. The hind legs are large compared with the forelegs; consequently, when moving on land, the nutria's front end is lower than the back end and it appears hunched. Nutria are approximately 24 inches long. Their round tail is from 13 to 16 inches long. Males are slightly larger than females; the average weight for a male is about 12-20 pounds, and average weight for a female is approximately 10 to 18 pounds. The ears are small and the eyes are set high on the head.
General Biology, Behavior, and Reproduction In summer, nutria live on the ground in dense vegetation, but at other times of the year they use burrows. Burrows may be those abandoned by other animals such as beavers and muskrats, or they may be dug by nutria. Under-ground burrows are used by individuals or multigenerational family groups. Burrow entrances are usually located in the vegetated banks of natural and human-made waterways, especially those having a slope greater than 45 degrees. Burrows range from a simple, short tunnel with one entrance to complex systems with several tunnels and entrances at different levels. Tunnels are usually 3 to 18 feet long; however, lengths of up to 150 feet have been recorded. Compartments within the tunnel system are used for resting, feeding, escape from predators and the weather, and other activities. These vary in size from small ledges that are only 1 foot across to large family chambers that measure 3 feet across. The floors of these chambers are above the water line and may be covered with plant debris discarded during feeding and shaped into crude nests.
In addition to using nests and burrows, nutria often build flattened circular platforms of vegetation in shallow water. Constructed of coarse emergent vegetation, these platforms are used for feeding, loafing, grooming, birthing, and escape, and are often misidentified as muskrat houses. Initially, platforms may be relatively low and inconspicuous; however, as vegetation accumulates, some may attain a height of 3 feet.
Nutria tend to be nocturnal, with the start and end of activity periods coinciding with sunset and sunrise, respectively. Peak activity occurs near midnight. When food is abundant, nutria rest and groom during the day and feed at night; when food is limited, daytime feeding increases. Individuals occasionally may be observed swimming, feeding, basking in the sun, or walking along a pond bank during the daylight hours, especially when nighttime temperatures are below freezing.
Nutrias are sensitive to low temperatures, with mortality attaining 80-90% following a few days of subfreezing temperatures. Cold winter temperatures are believed to be the main limiting factor preventing nutria from becoming established in much of eastern Oregon and at high elevations in western Oregon. Nutria generally occupy a small area throughout their lives. Daily cruising distances for most nutria are less than 600 feet, although some individuals may travel much farther. Nutria move most in winter, due to an increased demand for food. Adults usually move farther than young. Seasonal migration of nutria may also occur. Nutria living in some agricultural areas move in from marshes and swamps when crops are planted and leave after the crops are harvested.
Nutria have relatively poor eyesight and sense danger primarily by hearing. They occasionally test the air for scent. Although they appear to be clumsy on land, they can move with surprising speed when disturbed. When frightened, nutria head for water and either swim underwater to protective cover or stay submerged near the bottom for several minutes. Nutria's nose and mouth are valvular (can be closed to prevent entry of water), and their swimming abilities are comparable to that of muskrat and beaver. During pursuit underwater, nutrias can see and will take evasive action to avoid capture.
Reproduction: Nutria appear to breed throughout the year. Females sometimes give birth to their first litter when they themselves are only 8 or 9 months old. Each adult female produces two or three litters a year. The number of young per litter ranges from 2 to 11 and averages about 5. Gestation: requires 127 to 135 days. Development: At birth the young are fully furred, and their eyes are open; they are able to move about and feed upon green vegetation, and are able to swim within a few hours. The female mammary glands are located along the sides of the back, enabling the young to nurse while the mother is in the water. Weaning occurs at seven or eight weeks but the young may remain in the same burrow with the parents, enlarging the den for additional living space to accommodate families of their own.
Life Span: In captivity nutria have lived as long as 12 years, but the life span in the wild is probably considerable less.
Predators: Fox, bobcat, coyote, otter and human are among those which prey on adults, while mink, weasel, and great horned owl take some of the younger animals. Range Nutria are well established in the lowland areas of western Oregon and are scattered along several stream systems in the central and northeastern part of the state. Wild nutria were first reported in Oregon during the 1930s, including colonies along the Nestucca, Columbia, and Willamette Rivers in western Oregon, and the Umatilla and Grande Ronde Rivers east of the Cascades.
Habitat Nutria are semiaquatic, bank dwellers, thus usually occur in or adjacent to rivers, lakes, sloughs, marshes, ponds, and temporarily flooded fields. Areas supporting both an abundant supply of succulent vegetation and freshwater is required. Although mild temperatures are preferred, some animals in south Argentina and Chile thrive in cold climates and those colonies in eastern Oregon appear to have adapted to low winter temperatures. Muddy banks are preferred for homesites. The burrow entrance is located at the waterline and is connected by tunnel to an enlarged den well above the water level.
Food Habits Nutrias' natural food consists almost entirely of aquatic and semiaquatic vegetation (including grasses, rushes, sedges, cattails, etc). Nutria are especially fond of alfalfa, clover, root crops, and garden produce (cabbage, carrots, sweet potatoes, etc).
Damage 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.
Legal Status 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.
Exclusion 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.
Habitat Considerations 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. Hazing 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.
Repellents No chemical repellents for nutria are currently registered.
Trapping 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.

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