Proceedings of the Vertebrate Pest Conference

Northeastern California contains several extensive areas of natural and man-made wetland and marsh type habitats. These areas were void of muskrat (Ondatra zibethicus) until the early 1930s when deliberate introductions were made. Once a valuable renewable resource before the sharp decline in pelt prices and strict regulations on trapping, the muskrat has become a nuisance pest species for resource managers. Muskrats have caused extensive damage to water delivery systems, levees, dikes, stream and river banks. Other damage includes impacts on pasture, crops, livestock, property, fencing, fisheries, endangered species, and human health and safety. This paper will look at the types of damage caused by the muskrat and some of the management approaches being taken to reduce or alleviate this damage.