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Providing evidence to improve practice

Individual study: Recovery of drill Mandrillus leucophaeus populations following protection afforded by Bakossi traditional chiefs and instigation of the Mount Kupe Forest Project education programme, Southwest Province, Cameroon

Published source details

Wild C., Morgan B.J. & Dixson A. (2005) Conservation of drill populations in Bakossiland, Cameroon: historical trends and current status. International Journal of Primatology, 26, 759-773


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Educate local communities about primates and sustainable use Primate Conservation

A before-and-after study in 1971-2002 in tropical montane forest in Bakossiland, Cameroon found that after the implementation of an education programme by the International Council for Bird Preservation (ICBP) in 1992 alongside one other intervention, drills Mandrillus leucophaeus increased in population size by 1997. However, the authors did not provide information on the magnitude of the population increase. Drill group sizes did not change over time, season, habitat, or elevation. In addition, a drill hunting ban was initiated by Bakossi traditional chiefs in 1994. In 1997, a group of 400 drills was observed and since the year 2000, wildlife staff and villagers regularly reported direct drill observations in the area. Independent direct observations of drill groups and their size were recorded by different organizations working in the area. No data were provided on the impact of the education campaign on the species’ conservation. The study does not distinguish between the effects of the different interventions mentioned above.

Implement legal protection for primate species under threat Primate Conservation

A site comparison in 1971-2002 in five tropical forests with different management histories in Bakossiland, Cameroon found that drill Mandrillus leucophaeus populations that were officially protected by government legislation, decreased in numbers on Mount Mwanenguba, the Bakossi- and Mwenzekong Mountains, became extinct in the Loum Forest Reserve, and appeared to recover only on Mount Kupe. Drill group sizes did not change significantly over time, season, habitat, or elevation for Mount Kupe, or for all sites combined. Independent direct observations of drills groups and their size were recorded at all sites by different organizations working in the region.

Implement local no-hunting community policies/traditional hunting ban Primate Conservation

A before-and-after study in 1971-2002 in tropical montane forest in Bakossiland, Cameroon found that a drill Mandrillus leucophaeus population that was protected by a local hunting ban since 1994 along with other interventions, increased in size by 1997. However, the authors did not provide information on the magnitude of the population increase. Drill group sizes did not change over time, season, habitat, or elevation. Hunting was intense before 1994. For example, 103 adults were shot by two hunters on three occasions in 1990. After 1994, hunting was controlled and the first six drills were killed in 2002. In 1997, a group of 400 drills was observed and since the year 2000, wildlife staff and villagers regularly reported direct drill observations in the area. The drill hunting ban was initiated by the late Paramount Chief of Bakossi and subsequently supported by other Bakossi traditional chiefs. In addition, an education programme was initiated in 1992. Independent direct observations of drill groups and their size were recorded by different organizations working in the area. The study does not distinguish between the effects of the different interventions mentioned above.