Chimpanzees are one of the most recognized great apes, displaying remarkable intelligence and complex social structures. Their physical size, however, varies considerably depending on where they live, with certain populations exhibiting greater mass and stature than others. Identifying the “biggest chimpanzee” requires examining the two distinct species and the four recognized subspecies within the larger group.
Defining the Two Chimpanzee Species
The genus Pan contains two recognized species: the Common Chimpanzee (Pan troglodytes) and the Bonobo (Pan paniscus). While both are closely related, they exhibit consistent physical differences that immediately separate them in size. The Bonobo, sometimes called the pygmy chimpanzee, is notably more slender and lighter in build.
Adult male Bonobos typically weigh up to 45 kilograms (99 pounds), making them the smaller species. Male Common Chimpanzees in the wild generally range from 34 to 70 kilograms (75 to 154 pounds). This difference in mass excludes the Bonobo from the title of the biggest chimpanzee. Therefore, the focus shifts to geographical variations within the Common Chimpanzee species.
Pinpointing the Largest Subspecies
The Common Chimpanzee is divided into four geographically distinct subspecies: the Central, Western, Eastern, and Nigeria-Cameroon chimpanzees. Scientific data suggests that the Central Chimpanzee (Pan troglodytes troglodytes) consistently achieves the greatest body mass in the wild.
This subspecies inhabits forests across Cameroon, Gabon, and the Republic of the Congo. Adult males of the Central Chimpanzee population typically average around 59.7 kilograms (132 pounds). When standing erect, they can reach a height of up to 1.7 meters (5 feet 7 inches).
The largest wild individuals, often belonging to this Central subspecies, can weigh up to 70 kilograms (154 pounds). Captive males, benefiting from abundant resources, have been documented weighing as much as 136 kilograms (300 pounds). While these maximum figures represent the upper limits for the species as a whole, the Central Chimpanzee holds the distinction for the largest average size in its natural habitat.
Comparing Size Metrics and Sexual Dimorphism
Within the Common Chimpanzee species, a distinct difference in size exists between the sexes, known as sexual dimorphism. Adult males are significantly larger and more robust than females, which is influenced by male competition for mating access. For example, the average weight of a Central Chimpanzee male is roughly 30 percent greater than the average female weight of 45.8 kilograms (101 pounds).
This size difference extends beyond overall weight and stature to muscle and bone structure. Males develop more robust skeletons and exhibit better-developed muscle attachments because they take longer to attain full adult size and musculature.
A chimpanzee’s arms are disproportionately long compared to their legs, which is an adaptation for climbing and swinging. The spread of an individual’s arms can measure approximately 1.5 times their standing height. Their physical strength is attributed to a higher concentration of fast-twitch muscle fibers, allowing for powerful, rapid movements necessary for their arboreal lifestyle.