The Southern Amazon red squirrel (Sciurus spadiceus) was first described for science in 1818 by the German naturalist and historian Ignaz von Olfers, a diplomat who traveled extensively in South America, particularly in Brazil. It is found in the rainforests of Bolivia, Brazil, Colombia, Ecuador and Peru, and can be observed in the protected forests of Tambopata National Reserve. To the west, its range is also known to extend beyond lowland tropical forests into the foothills of the Andes.
While officially classified by the IUCN (International Union for Conservation of Nature) Red List as of Least Concern, given its broad range and presumed large and low density population, in many parts of the Amazon it is threatened by the reduction and fragmentation of its typical rainforest habitat, and in some parts of South America’s tropical forests it has also been hunted traditionally for food, particularly in the northeastern Peruvian rainforests around the city of Iquitos, and at Limoncocha in Ecuador.
As its name suggests, the Southern Amazon red squirrel is a dark red color. Its belly, however, is usually whitish or pale yellow. One of the largest squirrels found in South America’s tropical region, it is remarkable for its very long tail, fading from dark red to orange at the tip, which accounts for around half its overall length of between 50 and 60 centimeters (20 to 25 inches). Males and females are around the same size. The Sciurus spadiceus tricolor subspecies has been reported as being extremely dark brown, or almost black, in color.
While they are certainly well able to climb trees, in common with all squirrel species, Southern Amazon red squirrels actually spend much of their lives on the forest floor, choosing dense undergrowth as their preferred habitat, unless driven into the rainforest canopy by heavy seasonal rains and subsequent flooding, or when retreating in an effort to evade their main predators, which include jaguars and ocelots.
Active during the day, these herbivores specialize in the harvesting of large nuts with extremely thick and hard shells. As non-territorial squirrels, they can often be seen in groups, harvesting nuts from the same trees. Because they store the nuts they gather on the ground, they fulfill an important role in the ecology of tropical forests by acting as seed dispersers. Their alarm call has been reported as resembling a sneeze, after which they will chatter as a way or relaying information regarding a perceived threat to the rest of the group.