Blue Nile patas monkey
The Blue Nile patas monkey or Heuglin's patas monkey is a species of Old World monkey found in Africa along the Blue Nile river valley in Ethiopia, Sudan, and potentially South Sudan. While first described in 1862, it was synonymized with the common patas monkey in 1927. A 2017 study reclassified it as a distinct species.
Taxonomy
The species was described in 1862 by Heinrich Gottlieb Ludwig Reichenbach. Reichenbach's description was based on a live specimen from Fazogli and a skin from the vicinity of the White Nile, both received by Theodor von Heuglin, with a captive adult in Cairo confirming the species as distinct to him. However, in the first widely adopted taxonomy for Erythrocebus by Schwartz, all Erythrocebus monkeys were classified into three subspecies: patas, pyrrhonotus and baumstarki, creating a monotypic genus. This led to the synonymization of E. poliophaeus with E. patas. In 2017, Spartaco Gippoliti resurrected E. poliophaeus as a separate species based on its distinctive appearance and notable geographic separation from E. patas, with the IUCN Red List and American Society of Mammalogists also recognizing it as a distinct species.Conventionally, researchers apply ssp. pyrrhonotus to all patas monkeys from northeastern Africa, including Sudan, Ethiopia, Kenya and Uganda. Gippoliti restricted the name poliophaeus from those populations found in northwestern Ethiopia and eastern Sudan.
Distribution
This species is thought to be restricted to the area between the Nile and the western escarpment of the Great Rift Valley. It ranges from the vicinity of Metemma south to the Sudd. Although it is only known from Ethiopia and Sudan, it could potentially occur in South Sudan.In prehistoric times, this species may have had its range restricted to a montane refugium in western Ethiopia, through which it survived a period of aridification.