Dryas monkeys, also known as salonga monkeys, are found only in the Congo basin, on the left side of the Congo river. At one time, thought to be a subspecies of the Diana monkey, it is to different to be considered the same species.

While it is currently considered data deficient, there are experts who believe that in fact there are only around 200 remaining in the wild, and it is actually close to extinction. having said that, in 2019 it was discovered in Lomami national park at 8 locations. While it is unclear how many individuals this accounts for, what is clear is that it should only be listed as endangered.

This species prefers secondary forest locations. Although secondary forests are said to be preferred, these monkeys may also inhabit lowlands, rivers, or swampy areas of the Congo.^[9]

The diet of the Dryas is said to be made up of mostly plant foods, including fruits, young leaves, and flowers. As these foods are often unavailable, this species also consumes small invertebrates, such as insects, as a supplement