#oecomys

Long-furred Rice Rat Oecomys trinitatis

it has a wide distribution in Central America and South America, being found in southern Costa Rica, Panama, Colombia, Venezuela, Trinidad and Tobago, Guyana, Suriname, French Guiana, much of Brazil, eastern Ecuador, and eastern Peru. Its nests are located near the ground and its litter size ranges from two to four young.

Cleber's Arboreal Rice Rat Oecomys cleberi

It is found in the Cerrado domain in central-western Brazil and the Atlantic Forest domain of São Paulo.

North Amazonian Arboreal Rice Rat Oecomys auyantepui

It is found in Guyana, Suriname, French Guiana, and nearby regions of Venezuela and Brazil. It is an arboreal rodent known from the understory of primary rainforest.

Yellow Arboreal Rice Rat Oecomys flavicans

A mouse found in the Andes slopes of Venezuela and Colombia.

Rodents two days in a row? Sure, why not. This is Natterer’s Oecomys (Oecomys concolor), a rodent from northern South America, specifically the Rio Negro West region of northern Amazonia. They have a head and body length of 12.5 cm and tail length of around 15 cm [1]. The image above is actually of a non-specified Oecomys, but that is just because I was unable to find any images specifically of Natterer’s Oecomys.

Especially older information regarding them is difficult to assess, as for a long time, many species were lumped under their name. In 1960, Philip Hershkovitz consolidated 25 different species just under O. concolor and O. bicolor. This means that any studies on them around this time may very well have been studying other rodents [1] and many gene sequences labelled as Natterer’s Oecomys in gene databases come from far outside the range we accept for them now [2]. In general though, Oecomys appear to be specialised to live in trees, and while no detailed dietary research has been done, they have been claimed to eat primarily fruits and grains [3].

Natterer’s Oecomys was first proposed as a species in 1848 by Johann Andreas Wagner, based upon an individual caught by the titular Johann Natterer. The uniform “beautiful white” of their stomach which impressed Wagner and led to the species name is not actually very representative of the species as a whole. There have been several of Natterer’s Oecomys (within the narrower definition we use now) who have grey stomachs with hair which may even have buffy tips, making their species name somewhat ironic [1].