Primate Tales: Scarlet, Booker, and Jolie

Primate Tales is a new blog series that explores the lives of individual apes and monkeys at research sites supported by The Leakey Foundation. This second installment of our Primate Tales series introduces us to Scarlet, Booker, and Jolie, three chimpanzees living in the Ngogo chimpanzee community in the Kibale National Forest, Uganda. The Ngogo chimpanzees have been studied since 1993. At nearly 200 individuals as of August 2015, the Ngogo chimpanzee community is by far the largest yet described in the wild.

By Rachna Reddy, Leakey Foundation Grantee

Scarlett, a juvenile female chimpanzee from the Ngogo community of chimpanzees in Kibale National Park, Uganda. Photo ©Kevin Langergraber

In a thicket on a forest hilltop, two adolescent chimpanzees mate. Afterward, they rest on the ground. Scarlet lies with her cheek on her hands while Booker grooms her back. Booker is 13 years old, with lanky arms and bright, almond eyes. Scarlet is 12, sleek-furred and red-lipped. Adolescent chimpanzees are, like human teenagers, sexually, but not socially or physically mature. Although they have not finished growing up, they are able to have offspring. Scarlet anatomically advertises this: she has a large pink sexual swelling on her rump that indicates she is in estrus, or reproductively active and able to mate (humans—fortunately, I must admit—do not share this anatomical advertisement).

Booker, a juvenile male chimpanzee from the Ngogo community of chimpanzees in Kibale National Park, Uganda. Photo © Kevin Langergraber

Soon, Scarlet will likely emigrate to a new chimpanzee community where she will reproduce, but Booker will remain here, at Ngogo in Kibale National Park, Uganda, for his entire life. He will grow into an adult and fight other males for a position in a dominance hierarchy where high-ranking males have the most offspring. Still, even now, while he is small and low-ranking, Booker may have a chance to be a father. Adolescent and young adult males mate with females and some even manage to sire offspring. How do they accomplish this? Since these young males cannot directly compete with bigger, stronger adults, they likely use alternative strategies centered on females themselves.

Such female-directed mating strategies have been well documented in adult chimpanzees. Adult male chimpanzees dominate all females and are unusually aggressive to them. This aggression involves sexual coercion; adult males who attack females mate and reproduce with them. Males show more aggression to females they prefer, who are usually older females who have had many offspring.

For instance, east of this hilltop, Scarlet’s mother, Jolie, also has a sexual swelling. Unlike her daughter, Jolie is the target of severe male aggression. More than a dozen adult males surround her in a single tree, the highest-ranking and his friends close to her on branches while low-rankers sit on the ground below with their backs against tree buttresses, looking up at her. These males charge and attack each other and Jolie while she screams and tries to leave the tree.

Leakey Foundation grantee Rachna Reddy observing chimpanzees in Kibale National Forest, Uganda

This type of aggressive behavior begins during adolescence. Adolescence is a critical period for male chimpanzees, as it is during this time that they start to dominate females. During this awkward and in-between period of life, however, friendly interactions also occur between adolescent males and females, like Booker and Scarlet above. In my dissertation research, I will investigate how young males use both aggression and affiliation to mate with females, including their adolescent peers, who as immigrants, may also be social outsiders, and adult females, who they may have known for their entire lives.

You can help support long-term primate field research with a donation to The Leakey Foundation! Click here to support research like this.

Rachna Reddy was awarded a Leakey Foundation research grant during our spring 2016 cycle for her project entitled “The development of male reproductive strategies in wild chimpanzees.” You can read a short description of her project by clicking here



Origin Stories: Ancestor

Alesi, the skull of the new extinct ape species Nyanzapithecus alesi (KNM-NP 59050). Copyright: Fred Spoor

Origin Stories Season Two | Episode One | Ancestor

Just recently, the news media announced the discovery of a fossil ape called Alesi. This remarkable fossil was found in Kenya, and it’s from a time period where there’s a big blank spot in the fossil record of our family tree. This 13 million-year-old fossil tells us something new about the very early evolution of apes and even shows what the common ancestor of us and all the other living apes might have looked like. This episode of Origin Stories tells the story behind the discovery.

Bonus Content

3D animation of the Alesi skull computed from the ESRF microtomographic data. It shows first the skull in solid 3D rendering, then transparent surface rendering is used to show the endocast shape (light blue), the internal ears (green), and the permanent teeth germs (grey and brown). © Paul Tafforeau / ESRF

Photo Gallery


New 13 million-year-old infant skull sheds light on ape ancestry

Questions and answers about Alesi

New infant cranium from the African Miocene sheds light on ape evolution. Nengo, I., Tafforeau, P., Gilbert, C.C., Fleagle, J.G.., Miller, E.R., Feibel, C., Fox, D., Feinberg, J., Pugh, K.D., Berruyer, C., Mana, S., Engle, Z. and Spoor, F.  Nature 10 August 2017. doi:10.1038/nature23456.


Editor Julia Barton 

Series Producer Meredith Johnson

Associate Producer Shuka Kalantari


Sound Design Katie McMurran

Theme Music Henry Nagle 

Intern Yuka Oiwa

Additional Music Lee Rosevere



Origin Stories Season Two

Everyone wants to know who we are, where we came from, and why we are the way we are. The story of how we became human is a story of survival and adaptation, and it’s a story that stretches over millions of years.

What does it mean to be human?

No, really… What makes us different from chimpanzees? How far back can we trace our family tree? Who were our ancestors? How did we spread around the world? Why do we make art? And how can we answer these questions?

Origin Stories is The Leakey Foundation’s podcast about how we became human. In six new episodes, Origin Stories takes you behind the scenes of some of the most exciting new discoveries in the study of human origins and profiles scientists whose work sheds light on some of the answers to these big questions.

The new season of The Leakey Foundation’s Origin Stories podcast will launch on August 31, 2017, with new episodes released weekly through October 5, 2017. The episodes will feature Leakey Foundation grantees Shara Bailey, Jean Clottes, Alia Gurtov, Will Harcourt-Smith, Jean-Jacques Hublin, Ellen Miller, and Isaiah Nengo, along with National Geographic Explorer and Pulitzer Prize-winning journalist, Paul Salopek.

This season was edited by Julia Barton of Malcolm Gladwell’s Revisionist History. It was produced and hosted by Meredith Johnson with additional production by Shuka Kalantari, Audrey Quinn, and Neil Sandell. Sound design by Katie McMurran.

Origin Stories was made possible by generous support from Dixon Long. Additional funding was provided by Jean and Ray Auel, Sharal Camisa, Victoria and Barry Fong, Martha Lewis and Dennis Fenwick, Jeanne Newman, Sharon Metzler-Dow, Bill Richards, and Lisa and Bill Wirthlin.

Listen and subscribe on Apple Podcasts, Google PlayRadio Public, Stitcher, SoundCloud, or wherever you get your podcasts.

From the Field: Matt Tocheri, Indonesia

Matt Tocheri was awarded a Leakey Foundation Research Grant during our fall 2016 cycle for his project entitled “New archaeological excavations at Liang Bua (Flores, Indonesia).” For a short summary of his project you may click here. Here he updates us on the beginning of his 2017 field season. 

Liang Bua is a very special place, and coming here to excavate is of course always exciting. Reconnecting with our local team members who live in three hamlets (Golo Manuk, Teras, and Bere) within Liang Bua village is a wonderful time as we all greet each other, share news, and retell old stories as we drink coffee made from beans harvested from their gardens. Moke and Sopi, two homemade alcoholic drinks brewed by villagers across Flores, are often also passed around as we all celebrate the start of a new field season.

The Liang Bua Team at the start of our 2017 field season, funded by The Leakey Foundation.

Our archaeological research at Liang Bua is a source of great pride among people living in this area and on Flores more broadly. All of our local team members are incredibly experienced and have considerable archaeological skills and knowledge. Some of them took part in the excavations conducted here between 1978 and 1989, and their sons, grandsons, and many other relatives and neighbours have worked at the site since excavations began again in 2001. As many of our team members are older, deaths among us are an unfortunate reality, and the start of our field seasons often also comes with great sadness as we turn our thoughts to those of our team who have passed away since the previous field season.

This year we remember and honour Bapak Rikus Bandar and Bapak Tony Djubiantono. Bapak Rikus was a Manggarai elder from Teras and Golo Manuk, the large hill within which the cave site is located, and long-time foreman and local coordinator of the Liang Bua excavations. As a young man, he took part in the first archaeological excavations here in 1965. He was a continuous presence at the excavations from 1978–1989 and from 2001–2016. Two of his sons, Ansel and Agus, are also part of our team, and one of his grandsons started working with us on school holidays last year. For many years, he and his family were responsible for managing the site year-round and they accompanied countless visitors from all over the world who came here to take in the beauty of Liang Bua.

Bapak Tony was from Bandung, west Java. As a young man, he took part in several of the excavations at Liang Bua between 1978 and 1985. He received his PhD from the Natural History Museum in France, specializing in paleomagnetic dating methods, and was active in geological and archaeological research in Indonesia throughout his career. He was the Head of the Branch Office of Archaeology in Bandung between 1992–2004 and the Director of The National Research Centre for Archaeology in Indonesia (ARKENAS) from 2004 until his retirement in 2011. As ARKENAS Director, he oversaw and took part in research on Homo floresiensis as well as the national and international attention that followed the discovery.

Three of our local team members welcome Father Robertus Mbongor to Liang Bua prior to the ceremony honouring the lives of Bapak Rikus Bandar and Bapak Tony Djubiantono.

As our local team and their families are all Roman Catholic, together with them we arrange for a priest to come to Liang Bua and hold a special mass in honour of those we have lost. The wood and other supplies that we will use in the coming weeks to shore our excavation walls are first used to make pews for all of us to sit down during the mass, and the tables we will use for eating lunch, recording data, and discussing all things Liang Bua are arranged to make an altar. The priest, Father Robertus Mbongor, reveals he is from Akel, a small hamlet just on the other side of the Wae Racang, which is the river that runs ~200 metres in front of Liang Bua. He recalls playing in and around the cave as a child and in 1949, his father attended school here, the last year the cave was used for that purpose. For those who have never spent time here, it is too easy to think of Liang Bua only as the place where the remains of Homo floresiensis were discovered. But here, the cave is a regular part of the daily fabric of life for the people who live around it, just as it has been for countless generations before them.

Until I began taking part in the excavations at Liang Bua in 2008, I never fully realized or appreciated the special bonds that form among the team members of long-term field projects like this one. Like an extended family, albeit one that has an intense two-month reunion almost every year, we watch our children or grandchildren play with one another in and around the cave while we see each other all grow a little bit older, year by year.

A special mass held in May 2015 in honour of Bapak Rokus Due Awe, who passed away in Jakarta near the start of our field season that year. Bapak Rikus Bandar, who passed away this past year, is seen sitting on the cave floor wearing a traditional Manggarai hat and sarong to the right of Father Johanes Samur.

Although the ceremony is a Roman Catholic funeral mass, our Muslim, Hindu, and atheist team members sit and stand side by side with our Christian ones, and together we pay our respects to those that have died since our previous field season. Many sing; most pray; all of us remember.

Lagu Paskah (MP3)

A song of remembrance sung in the Manggarai language by local people from Liang Bua village. As recorded during the 2017 ceremony at Liang Bua honouring the lives of Bapak Rikus Bandar and Bapak Tony Djubiantono.

May you rest in peace Bapak Tony Djubiantono (2017), Bapak Rikus Bandar (2016), Bapak Petrus Lodo (2016), Bapak Deus (2015), Bapak Rokus Due Awe (2015), Bapak Gaspar, Bapak Stefanus, Professor Mike Morwood (2013), Professor Raden Pandji Soejono (2011), Bapak Zeus Sambut (2011), and Bapak Petrus Magar (2009). 

Questions and Answers About Alesi

Research findings on ‘Alesi,’ a newly discovered  13 million-year-old fossil ape species, were published this week in the journal Nature, and the story has been carried widely in the press. The research team behind the Nyanzapithecus alesi discovery has collaborated to put together this list of questions and answers.

Q: What is the difference between apes and monkeys, and where do humans fit in?

A:  Apes are typically characterized by the absence of a tail, whereas monkeys do have a tail. Humans evolved from a long extinct ape species, and we share the lack of a tail.

Q: How can you tell Alesi is an ape and not a monkey?

A:  Alesi has teeth like an ape rather than any kind of monkey that ever lived in Africa. In addition, Alesi possesses fully developed bony ear tubes, another feature shared with living apes that is not found in more primitive primates.

Akai Ekes (l) and John Ekusi (middle) watch as Isaiah Nengo (r) lifts the sandstone block with Alesi after six hours of excavation. © Isaiah Nengo

Q: Why is the fossil skull nicknamed ‘Alesi’?

A: It is taken from the new species name Nyanzapithecus alesi, which was suggested by John Ekusi, the discoverer of the fossil, because ‘ales’ means ancestor in the local Turkana language.





Q: How do we know how long ago Alesi was alive?

A: The rock layer from which the fossil derived could be identified. A sample of this rock was found to be 13 million-years-old by our project geologist Craig Feibel and dating specialist Sara Mana, based on measurements of argon isotopes. The time period is known as the Miocene.

Q: What is the Miocene?

A:  The Miocene is the geological age that lasted from approximately 23 to 5 million years ago. Apes emerged during this time period and became widespread in Africa and Eurasia.

Experimental setup at the European Synchrotron Radiation facility, used for the high resolution X-ray scanning of Alesi. The skull is mounted on a rotation stage in front of the detector, and a laser beam is used for accurate alignment. © Paul Tafforeau

Q: How can you see that Alesi was an infant rather than an adult?

A: Alesi still had its baby teeth, and none of the adult teeth had yet erupted. The baby teeth can no longer be seen because they broke off when the skull fossilized, but the roots are still in place. The unerupted adult teeth inside the skull can be seen with X-ray imaging.

Q: How do we know how old Alesi was when she/he died?

A: When teeth grow they leave daily growth lines, just like the rings inside a tree. Using an extremely sensitive form of X-ray imaging, our team member Paul Tafforeau could make these growth lines visible in the unerupted teeth of Alesi. By counting them he could calculate an age of one year and four months.


Q: Do we know if Alesi was a boy or girl?

A:  At present we cannot tell whether Alesi was a boy or girl. In humans and apes the features of the skull that distinguish males from females only appear after a certain age, and Alesi was simply too young to display these.

Alesi, the skull of the new extinct ape species Nyanzapithecus alesi (KNM-NP 59050). © Fred Spoor

Q: What did Alesi look like?

A: Compared with living primates the skull looks most like that of a baby gibbon, for example by having a relatively small snout. We don’t have direct evidence about the rest of the body because no other bones than the skull were found. However, there is one indirect clue. The balance organ inside the skull gives information about the way an animal moved around (see additional question below). In the case of Alesi, it suggests slower, more deliberate movements than the tree swinging of gibbons. Hence, Alesi probably did not have the long arms of gibbons that make this acrobatic behavior possible.

Q: If Alesi looked like a baby gibbon, does this mean that it was an extinct gibbon living in Africa?

A: No. The researchers found that gibbon head shape with a small snout evolved several times in primate evolution. For example, the living leaf-eating monkeys (colobines) look superficially like gibbons as well, despite being distantly related. Gibbon-like features evolved independently each time, and does not demonstrate that animals were related to gibbons.

Q: Why is Alesi a new species?

A: Its molar teeth are very similar in shape to those of other species in the genus Nyanzapithecus, which indicates that Alesi belongs to this group. However, its teeth are much larger, suggesting that it was a larger species than the others.

Q: Do we know how Alesi died?

A: The area where Alesi was discovered was long ago blanketed by thick layers of ash from huge volcanic eruptions. Alesi might have been buried and perished in one such ash fall, but we do not know for sure.

Q: Fossil skulls are regularly found and reported in the press. Why is this one any different?

A: Little is known about the time before the living apes started to evolve, which in Africa was only previously documented by isolated teeth and broken jaw fragments. Alesi is not only the most complete extinct ape skull yet found, but it also comes from this poorly understood time period.

Q: Does this discovery mean that humans evolved from apes 13 million-years-ago?

A: No. Alesi is from a time when the common ancestor of all living apes and humans was alive in Africa. In contrast, humans themselves diverged from apes much later, sharing a last common ancestor with chimpanzees about 7 million years ago.

Map of Africa and Kenya, showing the location of Napudet, where Alesi was found. © Isaiah Nengo

Q: Among the living apes, humans are least related to orangutans and gibbons, which both live in Asia only. Does this not mean that ape ancestors lived in Asia rather than Africa?

A: Some experts believe that the ancestors of all living apes evolved in Eurasia, while others believe they evolved in Africa first and then spread to Eurasia. Alesi and its direct relatives are all found in Africa and closely related to the living apes, supporting the idea that the living apes evolved in Africa.

Q: How can you see from the inner ear how an animal moved around?

A: The inner ear is not only the place where you perceive sound (sense of hearing) but also where you perceive how your head is moving (sense of balance). This balance organ leaves an impression in the surrounding bone, so that this can be studied even in fossil skulls that are many million years old. Detailed X-ray imaging revealed that Alesi had a balance organ (semicircular canals) that is associated with slower, more deliberate movements, rather than the acrobatic arm swinging of gibbons.

The work was supported by The Leakey Foundation and trustee Gordon Getty, the Foothill-De Anza Foundation, the Fulbright Scholars Program, the National Geographic Society, the European Synchrotron Radiation Facility and the Max Planck Society.


New infant cranium from the African Miocene sheds light on ape evolution.” Nature August 10, 2017. doi:10.1038/nature23456.

Nengo, I., Tafforeau, P., Gilbert, C.C., Fleagle, J.G.., Miller, E.R., Feibel, C., Fox, D., Feinberg, J., Pugh, K.D., Berruyer, C., Mana, S., Engle, Z. and Spoor, F.