Most people just drive straight past impala – after all, they’re everywhere in so many of our parks. But in Etosha and Ongava, we always take a second look. Because a fascinating subspecies of this animal lives here.
The black-faced impala (Aepyceros melampus petersi) is an arid-adapted subspecies of impala that is endemic to Namibia (IUCN Red Data Book 2005) and is classified as “specially protected,” according to the Namibian Government’s Nature Conservation Ordinance. The black-faced impala is unique because it has evolved in geographic isolation from the rest of the species over thousands of years in north-west Namibia and southern Angola.
It is now thought to be extinct in Angola – indeed, an estimated 3 000 black-faced impala are left in the wild, making this subspecies both endangered and endemic to Namibia – meaning that more than 90% of the world’s population occurs here. Poaching, droughts, inter-breeding with common impala and competition from livestock are thought to have caused such severe decrease in numbers. Almost half of the global population are found in Etosha National Park, with at least 1 500 individuals in five distinct subpopulations occurring around Ombika, Olifantsbad, Halali, Namutoni and Kaross. Private reserves such as Ongava Game Reserve, managed by Wilderness Safaris, has one of the largest populations of black-faced impala on private land (around 200 individuals), which has contributed enormously to the conservation of the subspecies.
Ongava’s population has been the subject of considerable research, focusing on home ranges and microhabitat use of radio-collared females (Matson, 2003) and in recent years, much knowledge has been gleaned about the black-faced impala’s ecology. Some key features that have been uncovered by the research include: • Black-faced impala form smaller herds than common impala because they live in an arid environment where food and water resources are scarce and spread out. • Black-faced impala have very large home ranges. Ewes at Ongava in the wet season had home ranges six times as large as common impala elsewhere in Africa (average = 33km²). • As many as 75% of lambs may die before reaching adulthood. The study showed that 50% died in the first two months of life, due to predation and other natural factors.
It is quite easy to tell the difference between common impala and black-faced impala, as they have
• a dark nose blaze,
• a longer, bushier tail,
• darker colouration,
• larger body weight (approximately 10kg heavier than South African common impala).
The Namibian national management strategy for the subspecies focuses on building up the population by establishing a protection zone for black-faced impala that excludes common impala entirely. These zones include the Kunene region, Etosha and its neighbouring farms, Erongo Mountain Wilderness Area and Waterberg Plateau Park.
At Ongava, about two-thirds of the population drink at the Ongava Lodge waterhole, as this is the core of their home range. So the next time you visit Etosha and Ongava, be sure to keep a look out for this unique, endangered and interesting subspecies!