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.

Western Lowland Gorilla Morphology

Gorillas, split into western and eastern species, are the largest extant primate and one of our closest living relatives. Western gorillas are physically distinguishable from those in the east by their shorter hair and typically reddish-brown crest. Individuals can vary from brown to blackish in colour, with young individuals exhibiting a white tuft. Adult males (up to 200 kilos), are twice the size of females and exhibit the characteristic ‘silver back’ on maturity and a pronounced head resulting from a bony structure known as the sagittal crest. Individual gorillas can be distinguished through their nose-prints: the shape and size of their nostrils, alongside associated lines and markings.

Western Lowland Gorilla Biology

Western gorillas live in family groups consisting of a silverback male and several females and offspring. Average group size is approximately 9 individuals although much larger groups of around 30 individuals have been known to exist. Gestation is close to that of humans with females giving birth every 4-6 years. Newborns are completely dependant on their mother and are initially carried on the female’s underside, and later on her back. Young have been observed suckling up to 4 years of age. However, by this time, they are frequently seen travelling alongside the silverback male, resulting in the gorilla-equivalent of a ‘kids-club’.

Juveniles increasingly gain confidence until sub-adulthood, when both male and female offspring disperse. Sub-adult black-back males leave the group and roam as solitary males, for up to and over 5 years, before establishing their own family group. Females never travel as lone individuals. Maturing females are attracted away from their natal group during interactions, either by solitary males or by group silverbacks. During their lifetime, females may make additional transfers to other silverbacks.

The stability of western lowland gorilla groups and the length of a silverback’s tenure are yet to be determined. Based on long term monitoring of groups and approximate age estimates, silverback males can hold tenure for at least 10 years. Groups disintegrate on the death of the silverback, leaving the females and young vulnerable to attack by leopards, or other silverbacks. As groups with more than one silverback are rarely observed, the number of solitary males in the environment, and hence competition for females, must be high. Gorillas in captivity have been known to live for over 50 years, but considering the degree of male-male competition, it is doubtful whether this is true in the wild.

Gorillas are active during daylight hours (from approximately 6:00 to 18:00 in equatorial Africa). They exploit a number of habitat types within the tropical forest mosaic, including primary, secondary, monodominant (Gilbertiodendron spp.), and herb (Maranataceae) forest, and forest clearings (or “bais”). For the most part western gorillas are terrestrial but both males and females also spend a considerable amount of time in trees. They dedicate up to 70% of their time to feeding. Due to the abundance of food remains left on gorilla trail, diet is the most studied aspect of their biology. Western gorillas have been found to be eclectic yet highly selective feeders. Unlike their mountain cousins, which mostly feed on abundant herbs, western gorillas consume up to 180 species of plants, as well as a several species of insects. Their staple diet is made up of the shoots and pith of a few common herbs. Depending on the season, these staples are supplemented by a variety of other items including leaves, roots, bark, and insects, as well as seasonally available fruits. As fruit is highly preferred but rare in the environment, western gorillas are thought to experience higher levels of competition compared to mountain gorillas, which in turn influences their socio-ecology. Direct conflicts over food appear more evident, and in their search for favoured fruits, western gorillas spend more time travelling (approximately 10% of their time), range further (up to 4 kilometres a day), and show considerably larger home ranges than mountain gorillas (totalling up to and over 30 km², PHP long-term data). 

When not found eating, western gorillas spend the remainder of their day resting, allowing time for the young to engage in extended play sessions. At night individuals either sleep directly on the ground, or in constructed nests (on the ground or in trees). In order to protect his family, the silverback always sleeps on the ground. During the wet season, individuals are more likely to make constructed nests, sometimes making an additional nest during the night, probably to protect themselves from the wet soil. These seasonal variations in nest-building create a problem when estimating group size from nest sites and well as confounding census data. Our current knowledge on western gorilla distribution and abundance today are based on nests counts, however, if gorillas decide not to make a nest or indeed make 2 nests, these density estimates are likely to be over-estimates. Researchers are now investigating new and more precise methodologies for counting gorillas. These are vital in order to detect future population trends and threats (such as Ebola), providing the conservation community essential information towards the continued protection of this critically endangered species.

The Munye, First Group of Western Gorillas to be Habituated at Bai Hokou

The Munye group (meaning “good thing” in the BaAka language), became well-known in the six years they were followed by the Primate Habituation Programme team (1998-2004). When first contacted, the group consisted of the silverback, Mlima (“mountain” in Swahili), four adult females, two infants, and possibly a sub-adult black back male. They were a group in its prime, ranging close to camp, which greatly aided the initial habituation efforts. At first Mlima tried to discourage the PHP’s approaches with impressive charges, but gradually over the years the team earned his trust and were allowed to gain intimate knowledge on the daily life of his family.

The group however, was not without its history. In November 1999, the team found Mlima severely wounded. He had lost two of his females, one with a still dependant infant. The evidence suggested that a leopard, or perhaps another silverback, had attacked in the night. Fortunately, Mlima slowly recovered but two months later, a third female departed, leaving Mlima, his sole female, Matata (“problem” in Swahili), and their infant, Ndimbelimbe (named after a local herb).

During the next years, Mlima appeared to be searching for new females, extending his known home range. His efforts paid off in May 2000 when he acquired a female, Elele (“ciacada”). Unfortunately Elele never seemed to establish herself within the group and emigrated just 2 months after. By the end of 2001, the programme’s goal was finally achieved and the PHP successfully opened the group to tourists. In late 2002, the group unexpectedly ‘disappeared’, the PHP teams searched in vain, thinking the worst. Finally, after almost 2 months, they were relocated north of their previous home range, and from that point on the teams never lost sight of the group again. In April 2003, with Ndimbelimbe growing in confidence daily, Matata transferred to another group, leaving the father and son to roam alone. Thus, through entirely natural events, the original group of 8 was now reduced to 2: the team were beginning to learn that life for a silverback in the wild is not always so easy.

After Matata transferred, Mlima extended his home range dramatically, his hoots echoing across the forest, whether in search of Matata or for new females is unsure. By 2004, at perhaps 30 years old, tired, and likely blind in one eye (stemming from the earlier encounter in 1999), Mlima seemed at the end of his reproductive life. Yet unexpectedly mid-year he regained his previously magnificent form and acquired a new female named Samba (“second wife” in the local Sango language). At first, Samba was timid, not only towards Mlima’s approaches, but also towards the PHP team, however with time she seemingly accepted her new family and associates. Unfortunately this idyllic life was short-lived, one month later, instead of encountering the Munye at their nests, the PHP team was faced with an agitated, unknown male. The following day, after extensive searches, Mlima was found mortally wounded; he died later that evening.

In attempting to defend and retain his newly-won female, Mlima had succumbed to a stronger male. Samba was never seen again but Ndimbelimbe returned to Bai Hokou camp over Christmas 2004, feeding extensively in the bai adjacent. Unfortunately he too was wounded, with an unusable arm, but at least he had survived. The team attempted to follow him but eventually had to give up: not yet having the full weight of an adult, he left few knuckle-pints to follow. Young and alone it is unlikely that he survived, but the team can never be certain.

Despite this group’s long history of natural, yet tragic events, the PHP, the scientific community (See Published Articles on Previous Research at Dzanga-Sangha: Cipolletta 1999, 2003, 2004, Cipolletta et al, 2007, Todd et al., 2008) and a multitude of visitors learnt much from the Munye. During its time, over 400 tourists visited the group, with their international fame further enhanced by their appearance in 4 major TV documentaries. In conclusion, the strength and yet gentility of Mlima inspired many who had the chance to know him, and the PHP is forever grateful to him for allowing us this honour.

Tracking the gorillas

Living in dense forest, western gorillas are especially difficult to track, a process essential to their habituation. High gorilla densities make follows of a single focal group challenging; their extended range increases the area that has to searched; a single group’s traces may be dispersed over 100’s of meters; and, as the PHP learnt from their first habituated group, western gorilla groups can disintegrate rapidly. In addition to these reasons, all animals have an inherent fear of humans, likely resulting from past hunting pressure, and tracking becomes more difficult when animals flee.
 

The key to the Primate Habituation Programme’s success is the exceptional skills, patience and dedication of the BaAka trackers. Their heightened senses and extensive forest knowledge are truly amazing: they can perceive the slightest of sounds and smells in the dense forest; detect inconspicuous imprints and traces within deep leaf litter; distinguish the species the traces originated from, their direction of travel, and the length of time which has since passed by. The BaAka are thus considered the backbone of the programme: allowing the habituation teams to maintain daily group follows, from 6h00 to 18h00, year round.

The Habituation Process

Habituation is a process by which an animal becomes accustomed to human observers, to the point where the observers have little influence on their behaviour. However, this process is not always so easy: western lowland gorilla habituation requires an investment of over 5 years of time and effort. In addition, habituation is not without its associated risks: habituated animals are easier to kill and thus should not be outside of protected areas. Also, during ad after the process, there is a strong potential for negative behavioural impacts and disease transmission. Due to their close relation to humans, the latter is considered a priority for gorillas habituated for tourism or research and from the beginning their health must be monitored daily and a series of guidelines developed to minimise cross-transmission. Data collection on their daily diet and movements is also vital to identify their ecological needs and home range.

Once a group is located, the key to habituation is daily follows of the same group and repeated contacts at slowly-decreasing intervals. However, in dense lowland forest visibility can be poor (frequently less than 15m) and animals’ inherent fear of humans makes gaining their confidence a difficult task. For theses reasons the PHP habituation teams use a ‘clacking’ noise when in proximity to the animals. This method allows the animals to perceive the teams even in the densest of forest patches, and to eventually associate ‘clacking’ with gorilla-friendly humans.

For gorillas, fear and avoidance of human observers are the dominant behaviours during the first years of group contacts. These traits are gradually replaced by aggression, in particular from the male, including loud vocalisations and dramatic charges and displays. This aggressive period is perhaps the most testing stage of habituation and depending on the individual characters can last for over a year. Fortunately, the silverback gradually recognises the human observers as a more-or-less neutral element in the environment, allowing increasingly closer contacts; in general, his offspring follow suit.

However, this is not the end of the process, although the silverback may mostly ignore human observers within 2-3 years, the females resist! The reasons behind this negative response to the habituation team are unclear, but it could well be that females view human observers either as a risk to their young, or perhaps as competition for food, or their mate. Thus the last stage of habituation consists of renewed male aggression, provoked by the screams of insistent females. Eventually the silverback supports them less and less and perhaps at 3-4 years after the start of habituation, they too gradually begin to ignore the teams.

The Makumba Group’s History

2000-2002

As the gorilla tracking tourist programme could not be based on one sole group, in 2000, the PHP teams started searching for a second group, building on their previous experience. By November 2000 a group of at least 8 individuals was located in an area adjacent to that of the Munye group. However, unlike the Munye group, it took just over 2 years before the teams could consistently follow them and know more of their home range. Not only did they express the usual fear reaction of unhabituated gorillas, but also follows were hampered by the existence of 2 other groups of similar size overlapping their home range. Gradually though, the teams began to differentiate them from other groups. This was particularly so for the silverback, subsequently named Makumba (“with speed” in the local BaAka language), reflecting the rapidity of his reactions towards human observers.

2003-2004
By 2003, the habituation teams were following the group daily and contact time with the group started to increase but sightings were still rare. Gradually the teams began to piece together the group’s composition, which at that time included Makumba, 4 females, 2 dependant infants, and 4 juveniles. As always, during the habituation process, accidents can happen. By 2004, overall the group was mostly ignoring the habituation teams. However Makumba was still displaying during contacts, characteristically charging to within 5m, and then dramatically lunging forward again. In April this reached its peak, and provoked by the scream of a female, Makumba bit one of the trackers. Fortunately the wound was not too severe and the tracker was soon back to work. Soon after, the reason behind this increased aggression became apparent, 2 new infants had just been born, and Makumba was simply serving his role as protective father. After this event the teams backed off the group for a while to prevent further incident but by mid-year progress was once again being made. It was at this time, that the first habituated group, the Munye, disintegrated.

2005-2006

In 2005, Makumba started receiving tourists, with the understanding that the group had not quite reached full habituation. Throughout 2005 and 2006, the group of gradually became more habituated but it was during this period that the females really started to provoke the silverback to react. With the group frequently spread, it was relatively easy to make the mistake of stepping between a female and her male.

In the beginning of 2006, a new infant, Bokata, was born to Mopambi but soon after a tragedy occurred. Mapopi, the almost 2-year old infant of Mopatapata was found injured and later died. The most likely scenario is that Mapopi fell from a tree but as the team only heard and not saw the event, one can never rule out excessive intentional or non-intentional aggression from another group member. The group stayed silent around the body for the rest of the day. Mopatapata tried putting the infant on her back, only to see him fall back down. The next day, still near the body, Makumba finally had to force the group away through his displays. Mopatapata left 2 months later. In July, Bombe, the most dominant female gave birth to Mobangi.

2007
In 2007, the number of interactions between the group and other males, increased dramatically. In particular there was an expansion of their range towards the south (Kongana) which proved unfortunate in terms of the ease of access to the group by tourists and film crews but also in terms of increased poaching pressure. It appears these males were especially attracted to Etefi, Makumba’s oldest daughter, then just classified as an adult female. In July, during one of these interactions, Etefi left the group and transferred to a solitary male. Although entirely natural, the habituation teams were understandably sad to see her leave. However, to their surprise, six days later she returned to the group following another interaction – obviously preferring family over her new male.

With Etefi still in the group, interactions with other males continued to occur throughout the year. Probably as a direct result, the group’s home range increased considerably (larger than any group ever recorded) - Makumba at all times aware of the need to protect his growing family and find ‘safe’ areas. It was during a time of peak interactions that Bombe, with the youngest and most vulnerable infant, and consequently a heightened need to be close to Makumba, was at her most defensive against the habituation teams. Her screams provoked some quite serious charges from Makumba but thankfully, though still vigilant of any genuine threats, he gradually stopped supporting Bombe’s unwarranted aggression. In fact, on a number of occasions Makumba even intervened during Bombe’s attempts at charging the team, blocking her path or herding her away.

In December, Malui (second in the female dominance hierarchy), gave birth to Mowane (nick-named Tembo by the trackers after the tree he was born in). This was the first western lowland gorilla birth to be observed in the wild. As witnessed before, Malui is a very calm and proficient mother, however her behaviour can sometimes be quite surprisingly. After only 2 days, she was putting Tembo on her back, a behaviour previously thought to occur much later.

The birth also came after the shortest inter-birth interval ever recorded for western gorillas (at 3 years 10 months), seemingly an overall trend for the Makumba group. If this length of interval was found to be typical for western gorillas, it would have important implications for their socio-ecology and conservation. Compared to mountain gorillas, inter-birth intervals have always been thought to be much longer for western gorillas due to higher levels of competition between females (based on their more frugivorous diet). However an alternative scenario could be that the increased quality of western gorilla diet balances out the increased competition, leading to a comparative birth rate. More data is needed, but this could indicate that western gorillas are able to recover from population crashes (eg. resulting from Ebola), more rapidly than previously thought.

Two weeks after the birth of Tembo, Silo, a sub-adult male, disappeared after an interaction. Whilst it is unusual for a sub-adult male to be accepted by another group male, transfers of young males to solitary males is not unheard of. However, since Silo had very much behaved as an integral part of the Makumba group, the habituation teams believe that Silo may have become a victim of his own insatiable curiosity, staying in proximity to the male without realising that his family had long-departed. Of course Makumba’s priority during the interaction would have been the protection of Tembo, moving away from the area as rapidly as possible. Interestingly, neither Makumba, nor any of other group member, ever showed any overt signs of missing Silo, but the habituation teams very much hope is alive and well.

Makumba’s Family Tree

Click on the images below for more information about each group member.

		Bombe				Silo - 2009
						Essekerende -03/2003
						Mobangi - 07/2006
Makumba		Malui				Mowane - 12/2007
						Massoko-Buli - 2/2004
						Mio - 2001
		Mopambi				Etefi - 2000
						Mai - 03/2003
						Bokata - 01/2006
		Mopatapata*				Kunga - 1999
						Mapopi - 03/2004*

* Mopatapata left 03/06 after the death of Mapopi; Silo left the group in 12/06

Distinguishing the females and the family lines of the Makumba Group

Bombe (offspring: Essekerende, Mobangi)

Malui (offspring: Mio, Mossoko Abuli , Mowane)

Mopambi (offspring: Etefi, Mai, Bokata)

History of Agile Mangabey Research

With the exception of one study in Gabon in the 1970s, up until recently no long-term research had been conducted on the agile managabey. However, in the last decade, one particular study by Shah at Mondika, on the CAR/ Congo border (1997-1999) has greatly contributed to our current knowledge on this little-known species. Shah’s research revealed the behavioural and ecological flexibility of agile mangabeys and contested earlier research concerning their reliance on river/ swamp habitats. Following on from the success of Shah’s study, the Primate Habituation Programme began following a large group of agile mangabeys in 2004.

Agile Mangabey Morphology

Agile mangabeys are medium-sized semi-terrestrial monkeys, with a grey to olive coat and short, fine hair. The underbelly and inner limbs are paler in colour, ranging from white to cream. The back, tail and outer limbs are tinged with darker hair, ranging from light grey to charcoal. The crown is tinged with darker as well as golden hair. A parting on the forehead exposes a small patch of light-coloured skin and forms a projecting brow tuft. Males (7-12 kg) are generally twice the size of females (5-7 kg). Individuals can be difficult to distinguish but may be recognised by their suite of injuries and scars (most often on the tail, limbs and genitals), as well as their size, coat colour and behaviour.

Agile Mangabey Biology

Agile mangabeys live in polygynous groups which can be most easily located by the loud 'whoop-rumble' call made by adult males, in particular at sun-rise. This call is distinct from, but similar to, the 'whoop-gobble' made by the grey-cheeked mangabey. In contrast to earlier accounts of their shy, retiring nature, agile mangabeys have been found to be exceptionally vocal, constantly chattering, screaming, alarming and 'gobbling' as they compete for access to food and mates.

The Agile Mangabey group at Bai Hokou

Since the conclusion of Shah’s study, Bai Hokou is now home to the only group of habituated agile mangabeys in existence. The Primate Habituation Programme first started following the group in November 2004 and, unlike gorilla habituation, within months the teams were continuously in contact with the managbeys. The group has proved exceptional in size: usually Cercocebus monkeys form groups of approximately 20 individuals, each led by a single dominant male; from early counts, the Bai Hokou group was around 120 individuals. This group size may not be so unusual in the area, as other large groups have been observed in the vicinity. Due to their extraordinary group size, habituation of the Bai Hokou group is ongoing, but in general they tolerate human observers to within 10m, and certain individuals (notably males) to within 3-5m. This allows un-interrupted observation of their behaviour.

In late 2006, astonishingly the group’s number almost doubled (to approximately 230 individuals), through a process termed ‘super-grouping’. All studies of Cercocebus mangabeys report temporary sub-grouping, but ‘permanent’ super-groups have rarely been observed. The most notable cases are the mandrills at Lope, Gabon (with groups up over 800 individuals), and the Black and White Colobus in the Nyungwe forest, Rwanda (with groups up to… ). The ecological causes and consequences of this behaviour are still poorly known but are most likely either related to anti-predation strategies, or abundant, quality food resources. Attempted predation events have been observed at Bai Hokou (in particular by leopards, eagles, and snakes), but due to the group’s spread and the absence of habituation teams during the night, its impact is difficult to assess.

In terms of food abundance, alongside their preference for both ripe and unripe fruit, the group act like vacuum cleaners of the forest floor, including in their diet a diverse array of seeds, shoots, insects, and mushrooms which they frequently store in their cheek pouches. It has been suggested that as the group’s range is focused around the bai system, that food may be more abundant and hence allow a larger group size. However, the groups total home range extends over kilometers, also including other habitat types in terra-firma forest. Additionally, in the dry season, when fruit is mostly absent, the group ranges further (up to and over 3km/ day), travelling far and wide in search of sufficient food resources for all its members. These seasonal ranging patterns greatly increase their total home range. Although difficult as yet to measure, this is when the group appears most spread, forming flexible sub-groups. This strategy is opposite to that of gorillas, which concentrate on a few staple foods in the dry season, and ranges less.

Another interesting event relating to group size was the occurrence of a major ‘birthing-season’ in July 2007, with most of group’s females synchronously giving birth. Another minor ‘birthing-season’ occurred later in the year in October, leading to perhaps 70-100 females in the group carrying infants at the same time. This may be a tactic on the part of the females to confuse or hide paternity, a strategy linked to increased male protection and reducing the risks of infanticide. However, it appears that certain females may associate with certain males, and males seem to mate-guard, thus increasing the male’s likelihood of knowing paternity. Alternatively, synchronous births could be a tactic to ‘swamp’ potential predators – no resident leopard could possibly eat so many new-borns. Another associated factor may be the infant-guarding behaviour of the adult males. When fighting, males often grab the nearest infant to protect himself from increased aggression, a successful tactic in most cases, but infallible, as males frequently exhibit injuries.

The agile mangabeys at Bai Hokou also exhibit a number of other exceptional and interesting behaviours, which in turn may be related to their very large group size. Soon after researchers began following the group, it became evident that certain individuals, mostly adult males, occasionally ‘hunt’ animal prey. Aside from insectivory, individuals have been observed chasing and catching blue duikers, Peter’s duikers, water chevrotains and a host of rodent species (including squirrels and mice). Such behaviour has only been reported in a handful of primate species (notably, baboons and chimpanzees), and was never observed at such frequency during Shah’s study. The importance of meat to their diet has yet to be quantified. The frequency of this behaviour in the Bai Hokou group may be a consequence of living in such a large group as duikers are frequently attracted to dropped fruits whilst the mangabeys are feeding. Smaller groups of mangabeys may not encounter duikers as frequently.

This unique long-term study has now begun to throw up some interesting questions. Preliminary research at Bai Hokou has focused on their basic ecology, but with such a large group, behavioural studies remain limited. However, in time more may be learnt on the reasons behind their large group size, and its consequent effects (time spent processing food in cheek pouches, the frequency of hunting behaviour, time spent in social interactions, and the timing and frequency of sub-grouping). 
 

Rules for Visitors to Bai Hokou

1. Visitors to the gorillas must be 16 years and older
2. To help prevent disease transmission, sick persons will not be allowed to visit the gorillas or the managbeys.
3. Group size is limited to three visitors, twice per day.
4. Visits to the gorillas and mangabeys are limited to 1 hour.
5. Visitors must always closely follow the instructions set by the guide or trackers to ensure safety of the visitor and animals. Visitors must remain behind the habituation team at all times. Any person deemed to disregard these instructions will be asked to return to the camp without refund.
6. To minimise stress on the animals and reduce the risks of disease transmission, a distance of 7m from the animals is strictly enforced.
7. Flash photography is not allowed with the gorillas or mangabeys.
8. To reduce the risk of disease transmission, we ask that visitors avoid defecating, vomiting and spitting in the forest. Visitors needing to sneeze or cough in the presence of the gorillas must use a handkerchief or clothing to cover their nose and mouth.
9. All items brought into the forest must return with the visitor. Littering is strictly not permitted.
10. Visitors participating in Bai Hokou activities do so entirely at their own risk.

Park Fees and Lodging

Equipment

Visitors are recommended to bring binoculars. Long trousers and long-sleeved shirts in neutral colours are ideal. Closed walking shoes are useful, although crossing small streams is common. Rain-jackets during the wet season are essential.

A typical gorilla sighting

Habitats around Bai Hokou vary significantly from open bais, open mono-dominant Gilbertiodendron forest to mixed forest and dense herb/liana forest. As a consequence, viewing gorillas can vary throughout the day. Gorillas spend most of their time on the ground but also a substantial amount in trees. Trees can provide fantastic views of several members at the same time, although sometimes the gorillas can climb up to 25m or more, making viewing more difficult. Western lowland gorilla groups can be quite spread, often limiting visitors to viewing one or two individuals at a time. However occasionally visitors are treated to spectacular views of the whole group when they visit bais. Several of the gorillas’ staple foods are found in dense vegetation, particularly during the dry season (Nov-Feb). Consequently, visibility can be restricted. Visitors may have to walk significant distances both in reaching the gorillas and during observation time. Vegetation can be extremely dense with thorny vines; visitors may have to cross water. The forest is a naturally dark, making photography challenging. Charges and displays are a natural part of the gorillas’ behavioural repertoire. If the gorillas charge, it is important not to move, and remain quiet, with eyes averted. While following the gorillas, moving quietly through the forest, is essential to ensure optimum viewing.

Objective

To contribute to the habituation of two western gorilla groups and one agile mangabey group for the ecotourism Primate Habituation Programme (PHP). The PHP is under the direction of the Dzanga-Sangha Project (DSP, funded by WWF).

Location

Assistants (one gorilla and one mangabey) are based at Bai Hokou or Mongambe camp. Both camps are in the Dzanga-Ndoki National Park in the Dzanga-Sangha Dense Forest Special Reserve, Central African Republic. In addition to western lowland gorillas and mangabeys, the region is exceptional both florally and faunally and renowned for its high mammal densities including forest elephants, chimpanzees, leopards, bongos, forest buffalos and various monkey and duiker species.
 

Qualifications

Bachelor’s or master’s level students seeking to gain experience in conservation biology, primatology and/or zoology are encouraged to apply. Opportunities to conduct small, independent thesis projects are available providing that studies can be carried out alongside habituation work and that research questions are in-line with the philosophies of the PHP and DSP. Previous field experience would be extremely valuable, though openings can be considered entry-level and a 'stepping stone' for someone who is serious about a career in conservation, field research and/or wildlife eco-tourism. Additionally, candidates are required to be motivated, responsible, flexible, mature and amicable, with an ability to work as part of a multi-national team. Knowledge of French is extremely useful, though a commitment to learn the local Bantu language, Sango, may suffice. Emergency evacuation insurance is mandatory (e.g., S.O.S. Insurance co.). Candidates are required to seek independent funding (to cover flight, short and long-term visa, food and email costs).

Duties

Responsibilities will primarily include contributing to the habituation of new gorilla groups or the mangabey group, and collecting data on their diet, behavior and ranging activities. Additional responsibilities may include conducting phenology, participating in large mammal surveys, and data entry. Field conditions are very remote, with limited access to modern conveniences ('running water' is a nearby waterfall and solar electricity, intermittent), fresh foods and health care. The candidate must be physically fit and may be required to work long hours in the dense forest under challenging conditions. Accommodation is tent-based. Communication with home countries is limited to email via satellite phone (though internet at the Project's headquarters is available). Daily contact with potentially dangerous animals such as elephants, gorillas, forest buffaloes and venomous snakes can be expected.

Applications

Send letter of interest, CV and 2 reference letters to phpapplications@yahoo.com