The value of individual nutria (Myocastor coypus) pelts is in direct proportion to pelt quality and size. Various factors affect pelt quality such as fur primeness, fur color, and holes in the skin. Pelt quality in nutria is thought to vary during different periods of the year; however, this has not been confirmed. Observations by O'Neil (1949) show that the Louisiana muskrat reaches the height of its prime from mid-January to mid-February. Shanks and Arthur (1952) found that the value of muskrat pelts in Missouri increased by 202 percent from September to December, because of increased pelt quality. The harvest of nutria has been scheduled to conform with the trapping season for muskrat (Ondatra zibethica). In general, the harvest in Louisiana has been permitted during a 3-month period from December through February. If additional time was required the trapping season was extended into March. Because of the increasing importance of nutria to the fur industry in Louisiana and ofthe importance of pelt quality to pelt value, a study was begun on Rockefeller Wildlife Refuge in 1961 to determine the monthly variation in nutria pelt quality. An additional purpose of the study was to compare the various factors affecting pelt quality (such as primeness, damage, and color) and to determine the months which would produce the greatest revenue from a given number of nutria. After the nutria was introduced into Louisiana in 1938, its population increased and by 1945 the animal had invaded practically all Louisiana coastal marsh areas (Dozier 1951). Nutria were trapped extensively for fur and by the 1961-62 season provided a fairly stable industry with the value of pelts taken totaling over $1 million annually (Louisiana Wild Life and Fisheries Commission, 1964). In Louisiana the harvest of nutria ranked second only to muskrat (Ondatra zibethica). Nutria also spread into agricultural areas adjacent to the marshes and numerous complaints of damage were voiced by sugar cane and rice farmers (Ensminger, 1956). As a result the Louisiana Legislature declared the nutria an outlaw animal in 1958, permitting the killing of nutria at any time and by any means. This law was later repealed and the nutria placed on the fur-bearer list with harvest regulations established by the Louisiana Wild Life and Fisheries Commission. During the 1961-62 trapping season the take of nutria surpassed that of muskrat (Louisiana Wild Life and Fisheries Commission, 1964). Trapping was permitted from November 15 until March I. Regulations in later years provided for a 3-month trapping season beginning on December I and terminating on February 28.
