The mountain nyala has undergone a substantial decline in recent decades, from an estimated 7,000 to 8,000 individuals in the 1960s (2) (11), to perhaps fewer than 2,500 today (1), although others believe it to number nearer 4,000 (4). It has also reduced in range, and remaining populations are fragmented, making them particularly vulnerable (1) (10). The main threats to the mountain nyala come from human activity within its range, with increasing human and livestock populations putting ever-increasing pressure on the species through illegal hunting, competition with cattle, predation by domestic dogs, and habitat clearance for agriculture, grazing, firewood harvesting and settlement (1) (2) (4) (10) (11). The species has been extensively hunted for its meat and horns, and there is continued pressure from the trophy hunting industry to increase hunting quotas (1) (4).
The mountain nyala population showed a dramatic increase during the 1980s following the creation of Bale Mountains National Park, but political and civil unrest in 1991 led to increased encroachment and persecution by humans, and the number of mountain nyala in the park fell to a low of around 150 to 260 animals. There has since been a good recovery, with an estimated 680 to 730 counted in the park between 2000 and 2001, and possibly over 1,000 since then (1) (10) (12) (13). However, less effective protection elsewhere has resulted in ongoing declines (9).