While it has long been known some lions in Ethiopia have a large, dark mane, extending from the head, neck and chest to the belly, as well as being smaller and more compact than other lions, it was not known it they represented a genetically distinct population.
The team of researchers, led by the University of York in Britain and the Max Planck Institute for Evolutionary Anthropology in Germany used DNA to show captive lions at the Addis Ababa Zoo are, in fact, genetically distinct from all lion populations for which similar data exists, both in Africa and Asia.
"To our knowledge, the males at Addis Ababa Zoo are the last existing lions to possess this distinctive [dark] mane," researcher Michi Hofreiter said in a University of York release.
"Both microsatellite and mitochondrial DNA data suggest the zoo lions are genetically distinct from all existing lion populations for which comparative data exist."
Lion numbers in Africa are in serious decline and two significant populations of lion, the North African Barbary lions and the South African Cape lions, have already become extinct in the wild, researchers said.
"We therefore believe the Addis Ababa lions should be treated as a distinct conservation management unit and are urging immediate conservation actions, including a captive breeding program to preserve this unique lion population."