The Bulindi chimpanzees

Araali is one of the community’s young adult males. He was orphaned in 2015 after his mother, Olive, collided with a speeding taxi while crossing the main road that runs through Bulindi. Araali was barely 6 years old at the time—still a juvenile and completely dependent on Olive. Thanks to support from his older brother, Moses, and his own indomitable spirit, Araali survived despite this setback. Today, he’s a handsome adult chimpanzee and one of the high-ranking males at Bulindi.

Gerald is a 16-year-old male and the oldest son of Mirinda. He’s ambitious and, as of 2025, he’s the top-ranked male at Bulindi. However, Gerald hasn’t yet established full control of the group to become the undisputed alpha male, since he’s reluctant to dominate his close ally, Jack. It remains to be seen if he has what it takes to lead.

Jack is a fiercely intelligent young adult male. He’s relaxed around people, including many of the local villagers. However, he has a tough side and can be quick tempered.  In 2024, supported by his age-mate and coalitionary ally Gerald, Jack overthrew the former alpha male, Moses. Although we expected that Jack would quickly assume the top role, he seems disinterested in formal leadership duties. Jack has a distinctly tall and lanky physique, which he shares with his younger brother, Rohen. 

Moses attained the alpha position at Bulindi at the relatively young age of 14. He led the community for four years until 2024, when he was overthrown by the coalition of Jack and Gerald. Moses is the older brother of Araali, and while the two brothers often groom and share food with one another, they are also rivals. After Moses lost his alpha position, Araali also began seeking to dominate his older brother, further adding to Moses’ humiliation. Moses is currently the 4th-ranked male in the community. 

Merrick is an 11-year-old male on the cusp of adulthood. Already, he’s started challenging the lowest-ranking of the adult males, Murry.  Merrick’s a strongly independent chimpanzee. When he was only 5 years old, he would at times travel with the older males apart from his mother, Mirinda. As an adolescent, he often spends time in his own company. Merrick is the younger brother of Gerald.

Rohen is Jack’s younger sibling. The two brothers have a strong bond and normally associate with each other. Although Rohen’s still an adolescent, he shares Jack’s confidence and occasionally bullies other chimps. We predict he’ll become a high-ranking male in the coming years, supported by Jack.

Leila’s an adult female in her mid-twenties. She’s a high-ranking female and very popular with the males. She’s also a very noisy chimpanzee with a characteristic rasping voice, which is easily identifiable to us from a long distance away. Leila became a grandmother in 2023, when her oldest daughter, Georgia, gave birth for the first time.

For a long time, we thought the Bulindi chimpanzees were isolated because no young females migrated into the community. In 2019, we were delighted when an adolescent female turned up, whom we subsequently named Kaije, which means “you’re welcome” in the local Runyoro language. Kaije had travelled almost 15 km from Wagaisa, her birth community, to reach Bulindi, traversing farmland, villages and trading centres, and crossing busy roads—an extremely hazardous journey for a lone young female. Kaije settled in well at Bulindi and has a 3-year-old daughter, named Kasangwe. 

Mirinda is a middle-aged female in her mid-30s. She’s a notably rotund female; her two mature sons, Gerald and Merrick, share her short and stout physique. In 2020, Mirinda gave birth to the only known set of twins at Bulindi; unfortunately, however, both twins died within a few weeks. Currently, Mirinda’s youngest offspring is a precocious 3-year-old male named Donovan. 

Georgia became Bulindi’s youngest mother when she was just 10 years old, which is a remarkably young age for a female chimpanzee to give birth in the wild. Most females migrate from their natal group during adolescence to start their reproductive lives in other communities. Georgia disappeared from Bulindi in 2022 when she was 9 years old, and we assumed she’d gone for good. However, migration is challenging for young females in the deforested and human-dominated landscape of the Budongo-Bugoma Corridor, and some females struggle to find other chimpanzee communities. After 5 months, Georgia returned to Bulindi, apparently having failed to locate other chimpanzees. She became pregnant and gave birth to an infant daughter, whom we named Gena, in late 2023. Georgia has a close relationship with her mother Leila; the two females range together and often share food with each other and with each other’s offspring.