Gorillas in the Takamanda Forest Reserve

An isolated population of gorillas has been known to occur in the Takamanda Forest Reserve and the adjacent Okwangwo forests of eastern Nigeria since the early 1900s. In 1904, Paul Matschie described the gorillas from this area as a distinct species, Gorilla diehli. Later taxonomic work reduced this species rank to that of a sub-species and eventually amalgamated it with other lowland gorillas, Gorilla gorilla gorilla. However, more recent research, including DNA analysis of hair and the re-measurement of Nigerian gorilla skull records, has provided new information that suggests that these gorillas are indeed more taxonomically distinct than previously thought.
Until recently, little attention had been paid to the population of gorillas on the Cameroonian side of the border and it was unclear whether gorillas still existed in the area until a WWF expedition in 1987 confirmed their presence. Furthermore in 1996 Jacqui Groves visited the Takamanda Forest Reserve and collected information from the local people indicating the continued presence of gorillas. In 1997 a large mammal census focusing on the gorilla population was undertaken, for which the field work, funded by WWF Cameroon, lasted for 14 months.
The Takamanda Reserve covers approximately 700 km² of which only about 20% is classified as "highland" (for the purposes of this study, areas were categorised as highlands when higher than 700 m) which predominate in the north and east of the reserve. The results of the recent survey show that hunting is clearly higher in the lowlands than in the highlands and that, as a result, gorillas are virtually absent from the lowland areas. Although gorillas are still present in the Takamanda Reserve, they are now almost entirely confined to the highland areas, which are subject to lower hunting pressures, by the local communities. A very rough estimate of gorilla density in the highlands is in the order of 1 gorilla/km². In the lowland forest, the estimate was approximately 0.06 gorillas/km², one of the lowest recorded in Africa.
If gorillas are found in roughly the same density in all of the highland areas as in two highland areas surveyed, it would provide an estimated population of 140 weaned gorillas. However, a further highland area surveyed in Takamanda provided no evidence of gorillas at all; this was near to a large village and almost no indication of large mammals of any species was found in the area. Therefore population estimates must be heavily weighted, and adjusted, by the proximity of highland patches to village areas, where hunting is the main economic activity.
The Mawne (sometimes referred to as Mone) Forest Reserve and the Oko Mountain area to the east of the Takamanda Reserve are also comprised of a mosaic of highland and lowland forest. Recent gorilla skull records collected during this study from the Mawne Reserve indicate their continued presence in this area. Further surveys have been recommended for both reserves, focusing on areas that are the furthermost from human habitation.

Jacqueline L. Groves

Jacqueline L Groves began working with primates in 1991 with Pandrillus in Nigeria. In 1995 she returned to co-ordinate the Pandrillus' Cameroon project, the Limbe Wildlife Centre focusing on the rehabililtation of orphaned apes. From 1997 she has worked with WWF Cameroon completing a gorilla survey in the Takamanda Forest Reserve.
(today Jacqui's name is Sunderland-Groves)

Cross River overview

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