Posts Tagged ‘painted tree rat’

Nutria (Myocastor coypus) have Invaded Richmond County, Georgia

January 10, 2020

I think I’m the first person to document the presence of nutria in Richmond County, Georgia.  I was driving down Mike Padgett Highway last week and spotted a large road-killed rodent in the suicide lane, and I assumed it was a small beaver.  On the return trip I got a look at the posterior and noticed it did not have the broad naked tail of a beaver, but it was much too large to be a muskrat.  This specimen was at least 24 inches long, not counting the 12 inch tail, while muskrats grow to just 7-12 inches long.  I pondered over what it could be, and it dawned on me that it was a nutria.  I reviewed the description and photos of nutria in Mammals of Georgia by Stan Tekiela and confirmed my identification. His book was published in 2011 and shows the known range of nutria in Georgia then was along the Atlantic coast and the most southern boundary of the state, but apparently they have expanded their range since.

Image result for nutria nursing while swimming

I have no doubt that I saw a road-killed nutria in Richmond County, Georgia.

I considered taking a photo of the specimen as proof, but it seemed ridiculous to go back and risk getting run over by a car in order to photograph a dead rodent.  Though the traffic is not normally bad at this location, the carcass was in the middle of the suicide lane around a curve in the road.  The specimen was located about half a mile from the nearest water source (Spirit Creek, a tributary of the Savannah River).  Perhaps it was traveling across land to a different stream in search of an unrelated mate.

This species has been expanding its range north through the Savannah and probably other River drainages in Georgia.  They are well adapted for aquatic life and breed fast.  A nutria can produce 4 litters a year of up to 11 kits.  A nutria’s tits are angled to its side, so the kits can nurse with their noses above water while the mother swims.  Their population can explode.

Nutrias are native to South America.  Fur farmers have introduced nutria around the world–the U.K., France, Italy, Russia, and most notably Louisiana.  Fur farmers invariably go bankrupt, and the nutria escape to the wild.  Nutria feed upon the bulbous stem of aquatic plants, often killing them.  This causes erosion when the plant dies and the roots rot away.  To prevent damaged wetlands, some people advocate eating nutria meat, and 1 company even makes dog food from the meat.  Reportedly, it tastes like a cross between turkey and pork.  Cold winters may also contribute to a range reduction, but in Richmond County, we haven’t experienced a severe winter since 2012/2013.

Nutria fossils have been found at 6 sites in South America, dating from the early-late Pleistocene.  Their closest living relative is the painted tree rat ( Callistomys pictus ), an endangered species found in the disappearing Atlantic rain forests of Brazil.

Image result for painted tree rats

Endangered painted tree rat, the nutria’s closest living relative.  They must have diverged from a common ancestor many millions of years ago–1 is arboreal and the other is aquatic.

As far as I know, I am also the only person to document the presence of star-nosed mole in Richmond County.  See: https://markgelbart.wordpress.com/2016/12/02/the-strange-little-star-nosed-mole-condylura-cristata/