It lives mainly in trees and are omnivorous, eating a wide variety of both plant and animals as food.

Although there are differences between individuals as well as between the sexes and across age groups, S. xanthosternos is described as having a distinctive yellow to golden red chest, belly and upper arms.

A band of short hair around the upper part of the face with speckled colouring contrasts with the darker surrounding areas.

Capuchins males stand around 40 cm (16 in) tall weighing an average of 4 kg (8.8 lb).

[5] Capuchins falling under the genus of Sapajus and Cebus are believed to have a common ancestor originating in the Atlantic forest.

[6] Populations of S. xanthosternos are restricted to the Atlantic forest of south-eastern Bahia, Brazil, due possibly to high degrees of interference from humans.

[7] The largest continuous area of forest in its known range, the Una Biological Reserve in Bahia, is estimated to contain a population of 185 individuals.

The remaining forest fragments tend to be surrounded by human activity such as farms, this is both beneficial and detrimental to the capuchins since they are able to raid crops to supplement their diet.

[9] The ideal size of a forest fragment in order to properly sustain a population of S. xanthosternos is deemed to be larger than a range of approximately 400 to 700 hectares depending on local conditions, with currently approximately 2% of forest fragments being over 400 hectares this poses an issue for conservation.

[11] Capuchins live in groups consisting of about 3-30 individuals with a hierarchy determining their social status.

Capuchins communicate making short and frequent yipping whines similar to a newborn pup.

Capuchins have acute olfactory senses helping them to distinguish scent marks left behind by other groups.

Hunting is a major threat to S. xanthosternos and its ability to have populations survive long-term in forest fragments.

[10][12] There is an elevated perceived risk of predation in the capuchins behavior when it is in an area of forest that give a greater advantage to predators, such as reduced canopy coverage in cabruca and in areas that transition from other forest types to a cabruca.

They mostly feed on plants such as fruits, seeds, flowers, nuts, leaves and stems, and nectar.

Any remaining habitats are protected including the largest place called Una Biological Reserve in Bahia, Brazil, home to about 185 Capuchin.