They are considered as frugivores-insectivores which means that their diet mainly consists of a variety of fruits, seeds, arthropods, frogs, small mammals, etc.

[5] However, the true current distribution of the Sapajus cay is a matter of debate between leading parties, and it is mainly due to the phenotypic characteristics of populations that live in different geographical locations.

[7] This species of capuchin monkey presents slight sexual dimorphism; the male being larger in body size.

Compared to the rest of the Sapajus species, S. cay exhibits a dark stripe of hair on the front of their ears, which resembles sideburns.

This alpha male typically serves as a protective figure, who also controls the access to food, and has priority to mate with the females.

Research indicates that these species have the ability to learn and retain information for long periods of time, which is a key quality for their high adaptability.

[14] The habitat of the capuchin's monkey species, respectively Cebus and Sapajus, is located in the tropical and subtropical forests of South and Central America.

They have a high level of behavioural as well as ecological flexibility, allowing them to reside in a wide range of habitats, including bush lands and savannas.

[5] In fact, the Sapajus cay species habitat is distributed among countries such as northern Argentina, south-eastern Bolivia, and eastern Paraguay.

[11] Some populations of Sapajus Cay monkeys reside in northern Argentina, in the provinces of Jujuy, Salta, Formosa and Chaco.

[2] The Sapajus Cay is also the only representative of its genus established in Paraguay, where they are located in the humid semi deciduous Alto Parana Atlantic Forest.

It is estimated that Sapajus cay monkeys are the most common kept primate pet in Paraguay, hence there is awareness of its threats, assisting conservation efforts.

[2] High population-density in areas South and Central America as well as legal and illegal selective logging, is destroying the Sapajus cay wildlife, ruining the fragment of forests they inhabit.

[14] In addition, their populations inhabiting what is left of the Argentinian forest are subject to serious threats as a consequence of habitat modification and conversion for agriculture production, as well as poaching (illegal hunting).

[15] In Brazil, the Azara's capuchin monkey has not been well studied, resulting in poor conservation actions due to lack of ecological knowledge of this species.