It is found in western Brazil, eastern Peru, Bolivia, and northern Paraguay.

[5] O. microtis is native to South America, its range extending from northwestern Brazil, south of the Solimões River and Amazon River, to the adjoining lowlands of Peru and Bolivia, northern Argentina, eastern Paraguay and the Gran Chaco plain.

In the Paraguayan Chaco it is associated with both dry and wet marshland, and has been reported from floating masses of vegetation.

[1][4] Breeding starts at a young age, even while still in juvenile coat, and pregnancy rates are high.

In Bolivia, pregnant females have been found in March, May, August and September, and the number of embryos varied from two to eight.