The California Department of Fish and Wildlife (CDFW) posted on their website a call to look out for an invasive population of nutria (Myocastor coypus).
Native to South America, these semi-aquatic rodents can reach up to two and a half feet in length, stand a foot tall and weigh 20 pounds. Nutria resemble native beaver and muskrat, but are distinguished by their round, sparsely-haired tails and white whiskers (see CDFW’s Nutria Identification Guide).
To date, nutria have been found in wetlands, rivers, canals and other freshwater habitat in Merced, Fresno and Stanislaus counties. Nutria can severely impact California’s wetlands, cause soil erosion, damage crops and levees, and reduce the stability of banks, dikes and roadbeds.
This type of damage has been observed in Louisiana, Chesapeake Bay and the Pacific Northwest.
The female nutria can produce up to 200 offspring, birthing a litter nearly three times a year.
The department is asking the public’s help in looking for and reporting nutria sightings in order to determine the extent of the infestation.
Signs are cattails and bulrushes eaten at the base with the stems left on the water. Also, their underwater burrows have entrances that may be exposed when the water recedes. Their tails can also leave a telltale mark on banks and shores.
Nutria tracks have four visible front toes and some webbing on the hind feet.
Assistance from local landowners and the public throughout the Central Valley, Sacramento-San Joaquin Delta and beyond is critical to successfully delineating the population. CDFW has a nutria webpage and a downloadable PDF with photos and detailed descriptions.
_ Information courtesy CDFW website: www.wildlife.ca.gov/Conservation/Invasives/Species/Nutria.