Nomascus leucogenys (Ogilby, 1840) is a crested gibbon of northern Vietnam, northern Laos, and southern China. Males are black with white cheeks and females are a rich buff color with a dark brown sagittal crest. It is among the largest of hylobatids (except siamang) and has unusually long arms for a hylobatid. Its diet includes fruits, leaves, small animals, and flowers. It is territorial and lives with stable pair-bonds in nuclear families consisting of a male and female and their offspring. It is “Critically Endangered,” possibly extirpated from China with only isolated populations remaining in Laos and Vietnam.

Leopardus braccatus (Cope, 1889) is a small felid—not much larger than a domestic house cat—commonly called the Pantanal cat. No comprehensive surveys have been conducted to determine how many L. braccatus exist in the wild. It is found in humid, warm grasslands and wooded areas of extreme northwestern Argentina, southwestern and south- and north-central (newly reported ranges) Brazil, Paraguay, and Uruguay. Habitat loss and degradation are considered major threats throughout most of its range. It is uncommon in captivity and museum collections, listed with all Felidae under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, and considered “Near Threatened” by the International Union for Conservation of Nature and Natural Resources in the pampas cat group ( =  L. colocolo).

Myotis simus Thomas, 1901, is a vespertilionid bat commonly called the velvety myotis. A small to medium-sized bat with the plagiopatagium attached at ankles and short (≤5 mm), woolly fur, it is 1 of about 100 species of Myotis worldwide and 1 of 15 South American species of Myotis. It is endemic to South America, occurring from Colombia and northern Brazil southward to Paraguay and northeastern Argentina in both terra firme and floodplain areas in lowland forest and savanna at elevations from 28 to 600 m. It is not of special conservation concern.

Akodon cursor (Winge, 1887) is a Sigmodontinae rodent commonly called the cursorial akodont. This small cursorial mouse has homogenous dorsal pelage that can range from dark to golden brown and it is 1 of 41 species in the genus Akodon. It is endemic to Brazil, South America, and is found in the Atlantic Forest, being the most abundant sigmodontine rodent of this large area. Deforestation within the range of A. cursor may not affect this species, because it is tolerant of human disturbance. Currently the International Union for Conservation of Nature and Natural Resources regards it as a species of “Least Concern.”

Sciurus stramineus Eydoux and Souleyet, 1841, is a large-bodied squirrel commonly called the Guayaquil squirrel. S. stramineus is characterized by a distinct grizzled-gray pelage with dark feet and ears, a long tail, and a distinctive white “collar” behind the ears. It is native to the western slope of the Andes, occurring from dry or humid tropical forests at sea level to high-elevation montane forests up to 2,000 m in Ecuador and Peru. S. stramineus is adaptable, adjusting to anthropogenic changes and living close to human settlements, in coffee plantations, with an introduced population in Lima, Peru. Because of a tolerance for living in proximity to humans, S. stramineus is also a concern for transmission of diseases such as leptospirosis and Chagas disease.

Cyclopes didactylus (Linnaeus, 1758) is a small, arboreal anteater commonly called the silky anteater. This nocturnal denizen of diverse forests has a disjunct range with a western population from Central America into South America and an eastern population in the Atlantic rain forest of Brazil. The main population of C. didactylus is listed as “Least Concern” by the International Union for Conservation of Nature and Natural Resources, but habitat loss and sugarcane production threatens its habitat in the Atlantic rain forest.

Sciurus spadiceus Olfers, 1818, is a sciurid commonly known as the southern Amazon red squirrel. S. spadiceus is a large-bodied tree squirrel with a variable color pattern, but typically has a reddish brown dorsum, a dark midline, a white venter, and a brown and orange tail. S. spadiceus ranges from southern Colombia and Venezuela, south through Peru, western Brazil, Ecuador, and Bolivia in lowland rain forest. This species is listed as “Least Concern” by the International Union for Conservation of Nature and Natural Resources.