The Primate Habituation Programme (PHP)
In late 1997, Allard Blom (WWF) established the Primate Habituation Programme (PHP) under Dzanga-Sangha’s Ecotourism Programme. The PHP has been a main WWF focus to protect and better understand the threatened and little-known western lowland gorilla. Its aim is to habituate gorillas for tourism and research and hence:
- Increase the economic value of the park through tourism
- Raise revenue for the National Park and local communities.
- Raise support (funding/ awareness) for gorilla conservation
The programme is a key success of WWF's work in CAR, learning a wealth of lessons along the way in terms of habituation and research. It provides visitors with the unique opportunity to see wild western lowland gorillas in their natural forest habitat, and has raised national and international awareness on the plight of the western lowland gorilla.
The base camp, Bai Hokou, was named after the adjacent forest clea
ring in which forest elephants have dug a large hole to exploit its mineral-rich soil ( “bai” means clearing and “hokou”, hole, in the local BaAka language). Bai Hokou rests at the heart of an extensive system of bais, offering excellent opportunities for research and tourism by attracting high densities of wildlife to the area. Long term ecological monitoring and studies on western lowland gorillas have been conducted at Bai Hokou since 1984 (see History of Western Lowland Gorilla Research), and gorilla habituation was attempted as early as 1992 (Remis), but at that time with limited success.
By 1998, the PHP team, under the direction of Chloe Cipolletta, had mapped an extensive trail system (mainly based on e
lephant trails), and located the main gorilla group in the area. The first habituated gorilla group, the Munye, was followed from 1998-2004. In 2000 the habituation of a second group began. It is this latter group, Makumba, that is currently enjoyed by a wealth of visitors: tourists, researchers, reporters, and film crews alike (e.g. National Geographic, Discovery, BBC, Canal Plus). In 2004, the PHP diversified its programme and began habituating a large group of agile mangabeys (Cercocebus agilis). The mangabeys, as well as a bai tour (with the chance to see the local forest buffalos and a variety of other wildlife), have been open to tourists since 2005. As of 2006, the PHP starting the habituation of another gorilla group at Bai Hokou, and expanded its activities through the establishment of a second camp, Mongambe, which provides the base for following a further two gorilla groups. Today the PHP employs over 50 staff and raises over 50% of the Reserve’s tourism revenue (through tourism, film, and research fees), which is fed back into conservation and community initiatives. This revenue, alongside the staff’s dedication and passion, has served to increase local awareness on the benefits the gorilla conservation.
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.
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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.
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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.
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 Silo - 2009 |
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 Essekerende -03/2003 |
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 Mobangi - 07/2006 |
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 Malui |
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 Mowane - 12/2007 |
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 Mopambi |
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| Mopatapata* |  |
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* Mopatapata left 03/06 after the death of Mapopi; Silo left the group in 12/06
Makumba (the silverback)
Makumba, meaning “with speed”, is the silverback of the group. A good-looking gorilla with a tall crest, muscular form, and a heart-shaped nose. He is predominantly calm and is often found waiting patiently for lagging group members to catch-up; he spends a significant amount of his time resting or sleeping. Makumba is usually found with an ‘entourage’ of infants trundling along after him, finding security and comfort at his side.
However, being the group’s protective leader, he can at times show considerable turns of speed, power, and aggression. He can cover 30m in seconds, break trees clean over, stand between bull elephants and the rest of the group as they pass-by, and if necessary use his impressive canines to inflict significant injuries. His proven success as the leader of the group for over 10 years has resulted in a healthy family group with 12 offspring, all but one surviving.
Bombe (adult female number 1)
The largest and most dominant of the females, she can be sufficiently intimidating even in the absence of Makumba. Despite her nature, she is quite an attractive female gorilla with a wide, flared nose and a permanently round stomach (Bombe being a very round, hard forest fruit). Her hair is light coloured and fine, particularly around the head, neck and shoulders. The most 'volcanic' and temperamental of the family, Bombe can within minutes, exhibit both aggressive and remarkably accepting/calm behaviour. A very protective mother, particularly with her youngest infant, Mobangui, and is often seen rescuing him from overly-boisterous play sessions, or restraining him from clambering about in the tree canopy. She is also very possessive of Makumba and is most often seen in close proximity to him. Already the successful mother of three, Silo, Essekerende, and Mobangui (link to each), she will no doubt to continue to be a source of contention!
Malui (adult female number 2)
Malui is the easiest adult female of the group to identify, owing to her prominent T-shaped nose print, strong brow ridge and cheek bones, slanting eyes and sticking-out ears (Malui meaning “ears”). The top of her head is relatively flat-looking, and has a significant crest at the back. Though not of the size and bulk of Bombe, she is a strong, wily female and is not to be challenged. Constantly contesting and usually monopolising food, she is also the source of much of the family's arguments. Malui is also a successful mother of three, Mio, Mossoko Abuli, and Tembo (link to each).
Mopambi (adult female number 3)
The most gracile of the adult females, Mopambi, named after a fruit tree, has long limbs and a slender body. She has a slim face, with obviously-indented cheeks and a long, drawn-out nose and mouth. One of the calmest and most passive individuals in the group, not much flusters Mopambi. She is always patient and careful with her offspring, allowing her youngest, Bokata, to roam and play as he pleases, until it's time to move on. A largely passive individual, the other adult females often dominate over her in competitive situations. In addition to Bokata, Mopambi is also mother to Etefi and Mai.
Kunga
Kunga (estim. date of birth 1999, sub-adult/ blackback male) is the oldest offspring. He is the only blackback in the group, but he still has mostly a juvenile body size and shape. He has always been the most darkly-coloured individual in the group with thick, seemingly well-groomed hair (Kunga meaning ‘hairy/black’). His face is mostly smooth and lacks any obviously distinguishing lines. An infant when the group was first found, Kunga is the only mother-less offspring in the group, Mopatapata leaving in 2006 after the death of her infant. Kunga has since grown up to take a strong supporting role to Makumba, at times both leading and protecting others, and is even developing an adult male 'strut'. He is spending an increasing amount of time away peripheral to the group, exploring and foraging on his own. Nevertheless he can frequently be located by his hoom-humming singing as brings up the rear of the group. Despite his progression into adulthood, he is still, nonetheless, one of the most playful group members, and is capable of rousing even Makumba into a frenzy of pig-grunting, wind-milling and play-boxing.
Etefi
Etefi (estimated date of birth 2000, sub-adult/ adult female) was named after a small forest shrub, and has a slim build and long legs identical to her mother Mopambi. Her face is very characteristic with strongly-indented cheeks and small eyes with two diagonal lines under each. Her 'sideburns' of thin, light-coloured hair can be the most useful characteristics when distinguishing her. Like her mother, Etefi is predominantly calm, quiet and reserved. However, under the influence of her brothers Kunga, and in the past, Silo, she can become very boisterous and playful. She often greets the habituation team upon arrival with a simple short grunt, and quite happily remains in their presence unperturbed. Etefi is on the cusp of adulthood and, like Kunga, has become increasingly independent. She has already left the group twice following group interactions with lone silverbacks but subsequently returned. However, it will only be a matter of time before she leaves her family permanently.
Silo
Silo (estimated date of birth 2000, juvenile/ sub-adult male, left the group in Dec. 2007 ) has a round body, with fluffy hair. His nose is wide and flat, with a distinctive indentation in its centre, filled with three wavy lines. Like his mother, Bombe, his coat is distinctly lighter in colour than the other older juveniles. His name means “alone” in the local BaAka language, after the fact that he was frequently found motherless, only in the company of Makumba, when the teams first started really observing the group (2003). A boisterous yet bashful character, Silo often terrorised the younger members of the group with his rough play. He was frequently seen initiating play with others, often by slapping the ground, a tree or the individual, and then running off play-grunting or head-bobbing. Although most likely just a year younger than Kunga, he was absolutely still young at heart and was one of the most inquisitive members of the group.
Mio
Mio (estimated date of birth 2001, juvenile/ sub-adult female) meaning “nose” in the BaAka language, is named after the distinctive line she possesses across her nose, making her the most recognisable member of the group. She is rather black with the bulky build of her mother, Malui. Mio at the age of six, sits approximately in the middle of all the juveniles and as a consequence is never quite included in the exploration parties of her older siblings, but is often too old to play with her younger siblings. As a result, she is often seen at her mother’s side. She shares her mother’s confident, sometimes prickly character, and stands her ground in disputes. Since the birth of her youngest brother, she is now fully occupied following her mother and trying to hold Mowane whenever she can.
Essekerende
Essekerende (born in March 2003, juvenile male), named after a forest fruit, has an instantly recognisable body profile; he has a large round belly, a small round head and short stick-thin limbs. His face is covered with character-giving lines and he has a nose not unlike his mother’s, Bombe, and older brother’s, Silo, but with an even more obviously flat and wide shape. His hair is fluffy and messy, and has a reddish tinge. A confident, easy-going and inquisitive individual, not in the least concerned with the presence of observers. He is fully independent from his mother and is most often found with his playmate Mossoko Abuli or following Makumba’s shadow. He shares with his mother a passion for food and is always seemingly chomping down on some fruit or termites.
Mai
Like (estimated date of birth March 2003, juvenile fe male) her mother, Mopambi, and indeed her older sister, Etefi, Mai has a slim, gracile build, with long slender limbs. She has a distinctive nose, which is long and straight with parallel lines across its bridge and with close-together nostrils. Mai meaning “water” has a gentle and quiet temperament. She often attempts to play unselectively with anyone and everyone around her, but if no-one responds, she is quite content to amuse herself with chest beating and solitary play. Lately she has spent a considerable amount of time with her recently independent younger brother Bokata, often carrying him around on her back.
Mossoko Abuli
Mossoko Abuli (estimated date of birth February 2004, juvenile male), means 'big head', due to his distinctive head which certainly, in the past, seemed out of proportion to his small body. He has very dark, thick hair. Like is older sister, Mio, he is developing a deep line on the bridge of his nose. He is the smallest independent individual in the group and retains the white 'tail' of newborns. Mossoko Abuli has a serious air, often too occupied with filling his belly than with play. Like Silo in the past, He spends the majority of time with his father, often seen trailing behind Makumba’s heel and quickly following on when Makumba decides its time to move on.
Bokata
At just over two years of age, Bokata (* January 2006) is still defined an infant. He is a small, long-limbed, skinny gorilla, with thin hair on his head and a long nose resembling his mother, Mopambi and older siblings, Etefi, and Mai. At a young age, he seemed to be suffereing from some kind of skin fungus, and was thus named ‘Bokata’ a type of forest mushroom. A hyper-active, confident and inquisitive young male, Bokata has already begun to make his bid for independence from Mopambi. He is often captivated by his human observers and, when his mother’s not watching, will creep forward to get a better look. He likes to clap his hands and walk bipedally and actively plays with both younger and older individuals of the group. Bokata is developing rapidly, and is fast catching up with Mossoko Abuli. He very recently begun to spend significant periods of time away from his mother, and is already showing a magnetic attraction towards his father’s side, often hurriedly trying to keep up with his long strides.
Mobangi
Mobangui (born in July 2006) at less than three years and is the second youngest member of the group. He is named after a forest vine and still spends much of his time being carried by his mother, Bombe. He has thicker, fluffier hair than the infant Bokata, and a round face with a pig-like nose. Recently, he has begun to attain some independence, but is still an unsteady walker and the ever-watchful Bombe is always there to snatch him up on to her back if danger approaches or play gets too boisterous. He has a growing interest in the observers which is bringing more opportunities to get to know him. Mobangui will grow up under the protection of the dominant female in the group, which will no doubt give him a headstart in life.
Mowane
Mowane (an infant male born in December 2007) is the newest addition to the group at only a few months in age. Whilst named ‘gift of God’ by the former CAR minister for the development of Tourism and Handicrafts, he is nicknamed Tembo, after the tree in which he was born. Even now he already has distinct lines about his nose like his mother, and older siblings, Mio, and Mossoko Abuli. Born to the feisty Malui, he is bound to be a well protected individual while growing up. His birth was the first Western Lowland gorilla birth to be witnessed in the wild and this unique event has provided new information as well as an unexpectedly rewarding experience for the team.
Distinguishing the females and the family lines of the Makumba Group
| Bombe (offspring: Essekerende, Mobangi) |
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| Malui (offspring: Mio, Mossoko Abuli , Mowane) |
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| Mopambi (offspring: Etefi, Mai, Bokata) |
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