Invasive 20 Pound Rodents Are Making a Comeback

California officials are promoting the invasive species hotline to catch the nutria, or real-life Rodents of Unusual Size.

(Photo courtesy of Wikimedia Commons)

Like Westley in The Princess Bride discovering that “Rodents of Unusual Size” are more than a myth of the Fire Swamp, California is finding that they wreak havoc in the real world.

California Department of Fish and Wildlife (CDFW) officials aren’t sure how nutria — or Myocastor coypus — reemerged in California. But they know they need to stop the spread, fast. Female nutria can give birth to more than 200 little ones within one year of reaching reproductive maturity — a point they reach just six months after being born themselves.

Without early intervention, nutria will deplete wetlands, erode soil, damage agricultural crops, and contaminate drinking supplies with parasites and disease that can spread to humans, livestock, and pets. Since March 2017, CDFW has documented more than 20 nutria in Merced, Fresno, and Stanislaus counties.

The capybara-looking rodents can reach 20 pounds in weight and 2.5 feet in body length, not including up to a foot in tail length. They were brought to the United States from South America for their fur and were eventually let loose in the wild.

Since then, Lousiana and the Pacific Northwest have struggled to completely eradicate the partially aquatic nutria as they destroy up to 10 times the vegetation that they eat. (Perhaps confusingly for Spanish speakers, “nutria” is the Spanish word for “otter,” and those adorable little scamps are a completely different species.)

If you see an animal that looks like beaver or muskrat but has white whiskers and round tails, CDFW asks to contact the Nutria Response Team through its online reporting form, email invasives@wildlife.ca.gov or call 866-440-9530.

View Comments