The nutria (Myocastor coypus), also known as coypu in South-America is a large, semiaquatic rodent that looks a lot like a beaver. It is the only extant species of the Myocastor genus, a name that can literary be translated to read “beaver rat” if you translate Myocastor from Latin to English. If you wonder why, just look at it. It looks a lot like a beaver, but the tail looks like the tail of a rat.
It really does look like a beaver as well. Image by Petar Milošević, posted with the Creative Commons Attribution-Share Alike 3.0 Unported license.
The nutria can weight up to 10 kilograms / 22 pounds, live up to 10 years (but the average life span is closer to 3 years), and tend to thrive in small colonies in freshwater mashes, but can at times also be found in brackish marshes. Like other rodents, they are able to breed very rapidly, and a single female can produce three litters each year. While most offspring die young, a single breeding pair can end up with building a population of 16,000 animals after only three years, given that their offspring keeps breeding, so this species has the potential for exponential growth once they settle in a new area.
The nutria is originally endemic to South America, but was released to California in 1889 in order to breed for its fur. Once the fur market collapsed in the 1940s, thousands of them were released into the wild when the farmers could no longer afford to keep and keep them.
Image by Philippe Amelant, posted with the Creative Commons Attribution-Share Alike 3.0 Unported license.
This of course ruined many marshland ecosystems in the United States, and they quickly spread over the US. The population that appeared in the 1940s eventually got (mostly) taken care of, but there are still some places that have them. The population in California mostly disappeared, but now it has returned, and no one know how or why!
And to us Europeans; it got released here as well, and it can still be found in many parts of Europe and Africa. We luckily don't have it here in Norway, but it's found in places such as France, Russia, and Germany.
The nutria is back in California!
During the last year over 20 different nutria has been spotted in freshwater habitats in California, and the California Department of Fish and Wildlife has no idea how they got there. The 20 different animals that have been observed includes both males, females, offspring and juveniles, so it’s safe to assume that a breeding population is settling in.
Image by Henri Sivonen, posted with the Creative Commons Attribution 2.0 Generic license.
The California Department of Fish and Wildlife Agency is getting really concerned, and has even set up a hotline where people can call if the spot a nutria in California. It will be exciting to see if they are able to get the population under control before it breeds into large numbers and destroy more ecosystems.
Why having nutrias in California is bad news for the ecosystem
While the nutria is a cute animal, it can have devastating effects on the ecosystem. Keep in mind that it lives in or close to wetlands, a type of ecosystem that is generally considered very fragile. When nutrias enter the ecosystem, they begin to forage the plants in the area, and a single nutria can eat as much as 25 % of its own weight every single day.
A nutria cage set out by the U.S. Fish and Wildlife Service. Image is Public Domain.
Most ecosystems are not capable of dealing with this huge loss of biomass every single day, and the result is that the wetland ecosystem begins to shrink in size. Once the main vegetation begins to disappear, the nutrias begin to dig for roots and rhizomes in order to feed on these, which causes further long-term damage to the ecosystem.
Wetlands is considered to be a very important ecosystem both by animals and humans. Not only does it provide a unique biotope that is inhabited by many interesting species, it is also providing cleaner water, storm surge protection, filtration of chemicals, and flood control, so it has a big economic impact as well.
Other posts about invasive species
Want to learn more about invasive species? Then just follow the links to keep reading!
- The American mink (Neovison vison) is found in almost all parts of Norway (and in many parts of Europe as well), and has spread from captive fur minks that have escaped their cages.
- Red foxes (Vulpes vulpes) were introduced to Australia for sport hunting in the 19th century, but ended up being responsible for the extinction of several native species, including the desert rat-kangaroo (Caloprymnus campestris)
- An invasive Asian carp species has been found just 9 miles away from Lake Michigan!
If you just like to read about huge rodents, then these posts might be interesting to you:
- The reintroduction of beavers (Castor fiber) in England has been a success; they protect the nearby areas from food and soil erosion, as well as provide the area with a thriving ecosystem.
- The world’s largest rodent, the capybara (Hydrochoerus hydrochaeris) have been imported to Japan to relax in Japanese hot springs!
Thanks for reading
I hope you enjoyed the post about the nutria/coypu. If you went to learn more about this big rodent, then I suggest that you follow the links in the text!
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