The Kibale Chimpanzee Project is a long-term field study of the behavior, ecology, and physiology of wild chimpanzees. Our researchers and field staff conduct daily behavioral observations on a group of ~50 chimpanzees in the Kibale National Park in southwestern Uganda. This research provides key contributions to understanding primate behavioral diversity, tracing the evolution of human biology and behavior, and conserving chimpanzees and their habitat.
Kanyawara chimpanzees are the focus of a new study on vocal behavior by Pawel Fedurek and colleagues. In many animals, such as pair-living birds and some primates, duetting or chorusing is believed to promote strong social bonds between calling individuals. Fedurek’s fieldwork at Kanyawara shows that such joint vocal displays might also play a bonding role in chimpanzees. The study examined the production of pant hoots – long-distance calls commonly given by chimpanzees. Since males often pant hoot together with other males, the researchers tested the idea that such chorusing reflects strong social bonds between males.
The results of the study supported this hypothesis. For example, a male was more likely to join in another male’s pant hoot if the calling male was his long-term friend. For chimpanzee males, maintaining bonds with other males is critical for obtaining social status and its associated benefits. This study shows that pant hoot chorusing might play an important role in such bonding.
However, the study also suggests that chimpanzee chorusing signals short-term affiliation between males, regardless of their long-term relationships. For example, male dyads, both friends and non-friends, were more likely to groom, or support each other in conflicts, on days when they chorused. Since chimpanzees form temporary sub-groups in which friends are not always present, forming short-term coalitions with available males may be beneficial. The authors suggest that pant hoot choruses facilitate the formation of such relationships in these complex societies.
We would like to congratulate Francis Rwabuhinga, Conservation Education Coordinator for the Kibale Snare Removal Program (KSRP), for his recent achievement. Francis was selected as the 2013 recipient of the Charles Southwick Conservation Education Commitment Award from the International Primatological Society (IPS). This award “recognizes individuals living in primate habitat countries that have made a significant contribution to formal and informal conservation education in their countries.”
Francis, a Kasiisi alumnus and scholar, obtained his BA in Environmental Science from Makerere University. Francis currently serves as an important liaison between the Kibale Snare Removal Program and the Kasiisi Project by managing conservation-based educational outreach programs in the local schools surrounding Kibale National Park. In the past, Francis has organized and led conservation presentations and wildlife club activities for the Kasiisi Project schools. The Kibale Chimpanzee Project is extremely proud of Francis’ achievements and knows how deserving he is of this prestigious award. Pant hoots to Francis!
This tour includes a tax-deductible donation to the Kibale Chimpanzee Project. Limited spots are still available. Read more about this exciting tour here: African Genesis_Uganda
Kibale Snare Removal Project (KSRP) has made many exciting changes in March. First, we have hired a new snare team ranger, Robert. This expands our employment of local Ugandans to five snare team rangers! The four veteran rangers, John O., Paul, John T., and Godfrey, were also granted well-deserved salary increases. With the expansion of our snare team, we are now better equipped to split the rangers into two teams, thus covering twice as much area as before.
With the strength of two snare teams, the patrolled area in March covered most of the chimpanzee research zone and was expanded to include surrounding areas, such as Kanyanchu and Sebitoli, which are also home to large chimpanzee communities. The team members found and removed a total of 22 snares in March. Well-constructed snares can be very inconspicuous and difficult for chimpanzees, especially juveniles, and other animals to detect. Snare removal is therefore a vital component of our conservation efforts at Kanyawara and surrounding areas.
Both teams also documented evidence of other illegal activity in the park, such as firewood collection, pole cutting, charcoal burning, and timber collection. The team reported that Piper guineense, a climber species, was cut and harvested, probably for sale in town. P. guineense, a close relative of black pepper, produces fruits that when dried can be used as a spice in cooking. The team also reported that approximately 17 trees were cut and burnt into charcoal in a forested area near the park’s boundary. The snare teams collect data and document all illegal activity in the park. We hope that our presence in the forest may help to discourage these behaviors in the future, but will also use the data to better understand where, when, and why these activities are occurring in the park.
We would like to thank and acknowledge our funders, Jane Goodall Institute – Netherlands and Austria, for their on-going support and devotion to chimpanzee conservation.
The Kanyawara chimpanzees are going to be featured in many of the talks and posters at the 82nd annual meetings of the American Association of Physical Anthropologists in Knoxville, TN. If you’re going to be at the meetings, come on by and check out all of the latest research happening at the Kibale Chimpanzee Project!
WEDNESDAY, April 10th
Undergraduate poster session
6:00 to 8:00 pm
Energetics of infant chimpanzees: Implications of nursing and feeding behavior by Joel Bray et al.
Growing up chimpanzee: A study of body size and growth patterns in Pan troglodytes by Nicholas Brazeau et al.
THURSDAY, April 11th
Session 11. Primatology Posters: Sex, Sociality, Ontogeny, Captivity
All day: The interplay between behavior and disease: Investigating pathogen transmission dynamics in wild chimpanzees with social network models by Julie Rushmore et al.
Session 15. Primatology: Sex, Aggression and Competition:
1:00 pm: The development of aggressive play behavior in wild chimpanzees by Zarin Machanda et al.
1:30 pm: Effect of opponent distance on post-conflict behavior in wild chimpanzees, Kanyawara, Kibale National Park, Uganda by Jess Hartel and Craig Stanford
2:30 pm: Intergroup aggrssion and within-group cohesion in wild chimpanzees by Martin Muller et al.
3:15 pm: Context of Copulation Calls in Wild Chimpanzees by Melissa Emery Thompson et al.
FRIDAY, April 12th
Session 21. Invited Symposium: The High Price of Success: Costs of Reproductive Effort in Male Primates and Humans
8:00 AM to 11:30 AM
Organized by KCPers Alexander Georgiev and Melissa Emery Thompson, Discussant: Richard Wrangham
9:45 am: Physiological costs of dominance and mating effort in male chimpanzees by Alexander Georgiev et al.
Session 38. Nonhuman Primates in Human-Modified Habitats: Explorations in Ethnoprimatology
Afternoon: How Mentawai Island primate characteristics affect hunters’ prey choice by Lisa Paciulli and Kristin Sabbi
SATURDAY, April 13th
Session 42. Paleoanthropology: Later Homo
8:30 am: Honey exploitation by chimpanzees and hunter-gatherers indicates an ancient use of fire by humans by Richard Wrangham and Zarin Machanda
Session 51. Primatology: Ecology, Behavior and Flexibility
2:45 pm: A cross community comparison of female chimpanzee (Pan troglodytes schweinfurthii) social behavior in Kibale National Park, Uganda by Monica Wakefield and Kyleb Wild
You can download the whole program with abstracts here. See you in Tennessee!
The Kanyawara chimpanzees are the focus of a recently published study in the Proceedings of the National Academy of Sciences examining patterns of tooth development. Researchers from the Kibale Chimpanzee Project partnered with Harvard Professor Tanya Smith to determine the age at which infant chimpanzees in our community erupt their first molar teeth. Our two wildlife photographers, Ronan Donovan and Andrew Bernard, spent two years in the field photographing infant chimpanzees in situations when their mouths would be open enough to see if their back teeth had come in. I’m not sure about Ronan and Andrew, but I can certainly think of worse ways to spend time than photographing baby chimpanzees playing with each other!
We obtained thousands of photographs and were able to determine that our infants erupted their first molar teeth before the age of 3.3. years. Interestingly, when we compared this pattern to our long-term behavioral data we found that infants continued to nurse long after these teeth came in. This was surprising since primate-wide patterns indicate that molar tooth emergence is related to the period of weaning. Instead, we found that molars come in around the time that infants begin showing adult-like patterns in solid food consumption. This is the first study of a wild population of primates that has both the dental and corresponding long-term behavioral data which means we can really test the relationship between tooth emergence and feeding/nursing behavior for each individual.
Understanding the timing of these developmental milestones in wild chimpanzees is particularly important because evolutionary anthropologists have been debating for years whether early humans followed ape-like or human-like patterns of growth. Since chimpanzees are our closest living relative, it is important to make sure that we document their development before we can fully interpret the fossil evidence. Prior to this study, almost all the research on dental development in chimpanzees came from captive individuals or from a small sample of skeletons collected in the wild and it is unclear how representative these data are of living wild animals. By using this novel photographic approach, our study shows that molar eruption in our chimpanzees is not delayed relative to captive animals and both are very similar to data gathered from fossils of early human ancestors.
For more information about this study and to see more photos and videos of our infants showing off their teeth, please check out our detailed press release here: http://www.heb.fas.harvard.edu/Press3/
An important goal for the Kibale Chimpanzee Project (KCP) is to reach out to local communities to share what we are learning about chimpanzees and to increase awareness about the conservation threats that chimpanzees are facing, both in Kibale and elsewhere in Africa.
At the end of September, members of the KCP team visited local primary schools to talk with students involved in Wildlife Clubs, which are extracurricular groups that participate in various environmental activities (click here for more information about these activities).
In his presentation, KCP photographer Andrew Bernard explained what it was like to observe chimpanzees in the wild and discussed the basics of chimpanzee social behavior, emphasizing chimpanzees’ similarity to humans and why they are in need of protection. Representatives from the Kibale Snare Removal Program (KSRP) talked about how illegal snare traps – even those meant to capture animals like bushpigs – can severely harm chimpanzees and how their daily patrol work helps to rid the park of these dangers.
Wildlife Club members showed great interest in these presentations and asked many good questions. It was also an excellent opportunity for students to interact with local role models who work in the field of conservation. We look forward to working with these groups again on future educational projects.
Special was the latest Kanyawara chimpanzee caught in an illegally set wire snare, which had tightly wrapped around her right wrist, causing a severe injury. Veterinarian David Hyeroba, who works with JGI-Uganda, removed Special’s snare in late July, assisted by the KCP team (see August 15 blog post).
We are happy to report that Special’s condition has steadily improved since her surgery. Special was observed again in mid-September, and by then, had regained some use of her injured right hand. She could not put weight on it while walking, but she was using her hand to scratch herself, an indication that she had recovered partial feeling in her fingers. She was also using her right hand for support while climbing trees.
Even more encouraging, when Special was seen in early October, she was observed gripping a branch with her right hand, showing partial dexterity in her fingers. We are hopeful that these improvements mean that Special may recover full or nearly full use of her hand, making her a very lucky chimpanzee and an intervention success story.
Most chimpanzees injured in snares will not be this fortunate, however, so it is imperative that KCP continues its efforts to remove snares set within the chimpanzee range.
-entry by Andrew Bernard
Though chimpanzees are not usually targeted by poachers in Uganda, they sometimes get caught in snares meant to catch game such as duiker and bushpigs. On the morning of July 28th, KCP researchers and field assistants observed a wire snare wrapped around the right wrist of Special, a sub-adult female in the study community. The injury was estimated to be about one week old and is the first one that has been observed at Kanyawara in 7 months. Special was followed closely for the rest of the day, and a veterinarian working with the Jane Goodall Institute-Uganda (JGI-U) was called to attempt to remove the wire.
The next day, researchers found Special in a large group of chimpanzees feeding in the northern part of their home range. The party spent the morning travelling, and Special’s injured wrist was obviously a severe physical and social impediment. She couldn’t use her right hand to walk, climb, or support any weight (see video here), and although she was travelling with the large party, she was often secluded, grooming herself and gnawing at the wire on her wrist. Her behavior was notably lethargic and unmotivated, likely due to the pain and her decreased feeding.
At about 12:30pm, JGI-U veterinarian David Hyeroba arrived. Special was resting on a low branch of a tree, lying with her back towards the vet – an ideal position for darting. Because the anesthetic takes about five minutes to take effect, and darted chimpanzees usually flee right away, losing Special before she fell asleep was a risk. That is exactly what happened! After Special was darted, she rushed down the tree so quickly that nobody could tell in which direction she went! The team unsuccessfully searched for her for 30 minutes, then luckily located Lanjo, a young adult male, who led them directly to Special, who was now fast asleep.
Special’s wound was very deep, with the wire cutting down to the bone almost around her entire wrist. David thought she might still regain use of her hand, however. So instead of amputation, he opted for a thorough cleaning and stitching of the wound. Special was under anesthesia for about two hours, and after another hour and a half of recovery, she began walking at a seemingly normal pace. She travelled a bit and rested for an hour before climbing into an old low-lying nest in the early evening.
Special is still moving quite gingerly. She climbs trees, albeit with an exaggerated effort, and still avoids using her right hand. She has bitten out her stitches, as David expected would happen. Unfortunately, Special was also beaten quite badly on August 8th by several adult males, which opened her wound even further. The wound bled, which is encouraging because it suggests that her hand is still vascularized. Special’s long-term prognosis is uncertain, but it seems likely she will never regain full use of her hand. This sad incident emphasizes how important it is for KCP to continue its snare removal efforts so that injuries such as Special’s can be prevented in the future.
-entry by Andrew Bernard
This summer, the Kibale Chimpanzee Project welcomed a number of student researchers, including Nick Brazeau and Alex Smith from Harvard University. Nick, a rising senior, is working on his senior thesis project by collecting body size estimates of the Kanyawara chimpanzees. Alex, a rising junior, is his tireless research assistant. It is difficult to measure body sizes of wild chimpanzees, because researchers can’t easily convince them to climb onto scales. Instead we employ non-invasive methods like photogrammetry. Nick has assembled an apparatus that contains two laser beams mounted in parallel at a set distance of 5 cm. The laser apparatus is attached to a camera, and the projected beams provide a size reference in the photograph.
For each chimpanzee, Nick and Alex measure multiple body parts, including the forelimbs, hindlimbs, trunk, back, skull, and testes. These measurements will be compared to body size estimates of chimpanzees using multiple methods, including a comparison with captive chimpanzees of known weights. Such data will be valuable in answering questions about growth, life history, the relationship between body size and dominance, and the costs of locomotion.