This patas monkey occurs in the Blue Nile region of Sudan and Ethiopia. A 2017 taxonomic reassessment treated the regional population as a distinct species, and the current Mammal Diversity Database also uses the name Erythrocebus poliophaeus.
In the adult male described in the 2017 paper, long dark gray to black hair covered the shoulders and upper forelimbs; the face and nose were black, and the underside was pinkish rather than uniformly white.
Species-specific observations in the natural range are sparse. The paper documents photographed animals near Bambesi and Assosa in Ethiopia. Recorded sites include woodland, cultivated land and bamboo forest, but this was not a habitat-preference study.
An extinction-risk assessment has not been added yet.