TL;DR: For the first time, a medium-sized agouti-patterned squirrel with white venter, Sciurus ignitus, was found in Paraguay, being found in the northern Chaco-Pantanal region of the country as mentioned in this paper.
Abstract: We document for the first time that Sciurus ignitus, a medium-sized agouti-patterned squirrel with white venter, occurs in Paraguay, being found in the northern Chaco–Pantanal region of the country, where the borders of Paraguay, Bolivia, and Brazil come together. Sciurus urucumus, the only species of squirrel previously known with certainty to range into Paraguay, occurs in the Chiquitano Forest of the northeastern Paraguayan Chaco. We provide details of the Paraguayan habitats for the known specimens of both species. At present, we know of no localities where the two species co-occur. We critically evaluate some of the morphological characters used previously to characterize S. ignitus. Interviews with local hunters, including Ache indigenous ones, coupled with an earlier published account, indicate that the squirrel Sciurus aestuans also occurs in eastern Paraguay's Departamento Alto Parana, although no specimens are now available from the country.
TL;DR: Sciurus ignitus (Gray, 1867) is a Neotropical tree squirrel commonly known as the Bolivian squirrel as discussed by the authors, which occurs within the evergreen lowland and montane tropical rain forests along the eastern slope of the Andes in Peru, Bolivia, and extreme northern Argentina, and the western Amazon Basin in Brazil and Peru between 200 and 2,700 m in elevation.
Abstract: Sciurus ignitus (Gray, 1867) is a Neotropical tree squirrel commonly known as the Bolivian squirrel. It is a small-bodied, understory and mid-canopy dweller that occurs within the evergreen lowland and montane tropical rain forests along the eastern slope of the Andes in Peru, Bolivia, and extreme northern Argentina, and the western Amazon Basin in Brazil and Peru between 200 and 2,700 m in elevation. S. ignitus is 1 of 28 species in the genus Sciurus, and 1 of 8 in the subgenus Guerlinguetus. The taxonomic status of this species, as with other small sciurids in Peru and Bolivia, remains ambiguous. S. ignitus is currently listed as “Data Deficient” by the International Union for Conservation of Nature and Natural Resources.