By J. Wesley Allen, Environmental Scientist
The Muskrat and North American Beaver have adapted to the increasing number of stormwater ponds and facilities, and can cause huge headaches if not recognized and controlled.
Muskrats are small dark brown to black aquatic rodents (16-24 in., 1.3-4.4 lbs.) that live in ponds and wetlands throughout most of the United States and Canada, feeding on the aquatic vegetation found there. Muskrats are prolific breeders and can have two to three litters of up to eight young per litter every year. Muskrats were once trapped extensively for their fur, but reduction of trapping and predator numbers have allowed muskrat populations to remain strong, even with the loss of wetland habitat.
The muskrat has moved into many stormwater ponds, wetlands, and facilities. They can seriously damage these areas by burrowing into embankments, leading to massive erosion and even pond/facility failure. They can also eat installed and beneficial wetland plants. Because they breed prolifically, the population can quickly become destructive. They are active mainly at dawn or dusk, but burrows in the embankment near the water and disappearing aquatic vegetation are indicators of muskrats. There are very few preventative measures to keep muskrats from your pond, but keeping cattail populations under control can reduce the risk. Trapping is the best method to control muskrat populations.