History of Western Lowland Gorilla Research

Up until the mid-60’s, most information on western gorillas came from expeditions led by zoos and museums to collect live or dead specimens from the wild. In 1964 the first studies on wild western gorillas were carried out by Jones and Sabater Pi in Equatorial Guinea, albeit in disturbed and degraded habitat. In the mid-1980’s Tutin and Fernandez, later joined by Rogers and Williamson, began their study of western gorillas at Lopé in Gabon. Although never quite successful in their attempts to habituate gorillas, this long-term study provided a multitude of baseline ecological data and clarified gorilla distribution across Gabon. At the same time Richard Carroll and Michael Fay undertook the first rigorous surveys of western gorillas in south-western CAR. The latter two confirmed an abundance of gorillas in the Dzanga-Sangha region, as well as exceptionally high densities of other wildlife. With the aid of WWF, the results of these surveys greatly contributed to the establishment of the Dzanga-Sangha Special Dense Forest Reserve including the Dzanga-Ndoki National Park in 1990.


Soon after their initial survey work, both Carroll and Fay began long-term ecological research on the gorillas in the region (at Bai Hokou and Ndakan respectively). These studies were followed by a number of others in the 90’s (in CAR: Remis, Goldsmith, Blom, and Cipolletta at Bai Hokou; on the CAR/ Congo border: Doran at Mondika; in Congo: Kuroda, Mitani, and Nishihara at Ndoki, Olejniczak and Parnell at Mbeli bai, Bermejo at Lossi, and Magliocca at Maya Nord bai). These studies provided more detailed information on western lowland gorilla group size and composition, diet, tree use, nesting, foraging, and ranging behaviour. The onset of bai studies (Mbeli and Maya Nord) in particular, finally allowed direct observations and the collection of demographic data. However, in reality gorillas spend little overall time in bais and the lack of habituated groups still restricted data collection in the forest to indirect signs and chance encounters. In this respect, Bermejo’s study proved to be a breakthrough, the Lossi gorillas allowing prolonged direct observations in the forest, apparently due to their infrequent contact with humans in the past.


Then in 2001, under the direction of Chloe Cipolletta and funded by WWF, the Primate Habituation Programme at Bai Hokou made Dzanga-Sangha home to the first ever truly habituated group of western gorillas, the Munye group. Since the habituation of the Munye group, one other site, Mondika (CAR/Congo) has also successfully habituated gorillas, and several other gorilla research sites in Gabon and Cameroon are attempting habituation. Thus after over 4 decades of study, researchers finally have access to habituated western gorillas to detail their social lives and ecological influences on their behaviour. However now time may be the issue: the number of habituated groups across sites remains low, while the threat of Ebola remains imminent.