COMMON CHIMPANZEE

Pan troglodytes

Geographic Distribution and Habitat

Common chimpanzees can be found across the forests and savannas of equatorial Africa. Their range includes the countries of Sierra Leone, Angola, Tanzania, and Congo where they make their homes in a variety of habitats from savannas to tropical rainforests, low-altitude forests, and mountain forests.

Four subspecies of chimpanzees have been identified, based on differences in appearance and distribution:

    • Western chimpanzee (P. t. verus) in Guinea, Guinea-Bissau, Mali, Senegal, Sierra Leone, Liberia, Ivory Coast, and Ghana
    • Central chimpanzee (P. t. troglodytes) in Cameroon, the Central African Republic, Equatorial Guinea, Gabon, the Republic of the Congo, and the Democratic Republic of the Congo
    • Nigeria-Cameroon chimpanzee (P. t. elliotiin Nigeria and Cameroon
    • Eastern chimpanzee (P. t. schweinfurthii) in the Central African Republic, South Sudan, the Democratic Republic of the Congo, Uganda, Rwanda, Burundi, Tanzania, and Zambia
    • And possible a fifth subspecies: Southeastern chimpanzee, P. troglodytes marungensis, in Burundi, Rwanda, Tanzania, and Uganda. It is being argued that this subspecies is the result of enough variation between the northern and southern populations of P. t. schweinfurthii to warrant its own subspecies classification
Chimpanzee range, IUCN 2018

Size, Weight, and Lifespan

Fully upright, these great apes can stand as tall as 4 to 5.5 feet (1.22 m to 1.68 m). Adult males typically weigh between 88.2 and 132 pounds (40 to 60 kg); however, the largest male chimpanzees can weigh as much as 150 pounds (68 kg). Females weigh slightly less, typically between 70.5 and 104 pounds (32 to 47 kg) with the largest female chimpanzees tipping the scale at 110 pounds (50 kg).

Average chimpanzee lifespan in the wild is between 45 and 50 years, with some living as long as 60 years.

What Does It Mean?

Eponymous:
​Of, relating to, or being the person or thing for whom or which something is named.

Visit the Glossary for more definitions

Appearance

Sharing with us more than 98 percent of the same DNA, chimpanzees are more closely related to humans than to gorillas or orangutans.

As babies, chimpanzees’ expressive, human-like faces are bare of fur and pinkish in color, as are the palms of their hands and soles of their feet. But as they mature, this pinkish skin coloring changes to black. White beards adorn the underside of chins for both males and females.

Large ears that frame the faces of these primates provide them with excellent hearing. Endowed with good eyesight and color vision, chimpanzee’s forward-facing eyes allow them to clearly focus on objects. A pronounced brow-ridge above their eyes suggests a contemplative appearance.

Chimpanzees’ arms can be one-and-a-half times the length of their bodies, enabling them to walk on all fours (informally called knuckle-walking and formally known as quadrupedalism). Their long, slender fingers and opposable thumbs and big toes allow chimpanzees to easily grip objects.

A coat of long, thin strands of black hair covers their bodies and helps to keep chimpanzees warm in higher altitudes and also provide their skin with protection from the sun.

Inside their wide mouths adult chimpanzees, like humans, have 32 teeth that allow them to grind up plant matter; their longer canines assist in tearing into flesh.

Diet

Like their human cousins, chimpanzees are omnivores. That is, their diet consists of both plant and animal life. While the bulk of their diet is comprised of seasonal fruits, leaves, flowers, bark, seeds, and nuts, chimpanzees also hunt and eat mammals smaller than themselves, including other primates such as colobus monkeys. Groups of chimpanzees have cooperated to successfully stalk and kill young antelopes, often using sticks as weapons. To munch on one of their favorite snacks, termites, chimpanzees will use a twig to dislodge the insects from their nests. They use rocks to smash open nuts and use leaves to catch water.

Behavior and Lifestyle

Chimpanzees forage 6 to 8 hours each day; peak activity is in the early morning and late afternoon. Following a network of known paths, they cover most of this territory by walking on their knuckles. Occasionally, they will walk upright (the scientific term for this behavior is “bipedalism”) and are capable of doing so for 0.6 miles (1 kilometer). But much of their time is spent hanging out in trees, eating and sleeping and where the younger chimpanzees, especially, swing from branch to branch.

Grooming is a favorite chimpanzee pastime that helps rid them of parasites and helps to strengthen social bonds. Playing is a favored activity with the younger chimpanzees, while breeding occupies the adults. Each night, at bedtime, chimpanzees build a new nest out of vegetation and go to sleep.

Chimpanzees’ innovative mastery of tool use and problem-solving capabilities highlight the dimensions of their intelligence, drawing comparisons to human intelligence. Their emotional intelligence–their ability to feel grief, joy, anger, and empathy . . . draws further comparisons to humans.

Fun Facts
The common chimpanzee is one of two pan species. The smaller and less aggressive bonobo (also known as the pygmy chimpanzee) is the other, inhabiting the region south of Africa’s Congo River.

Chimpanzees and humans are believed to have descended from a common ancestor who lived around 8 million years ago.

A chimpanzee brain is structurally identical to a human brain and chimpanzees are capable of reasoned thought and abstraction.

Captive chimpanzees have been taught to use human sign language.

Daily Life and Group Dynamics

Our closest living relatives are highly social creatures who live in multi-male, multi-female communities. These complex chimpanzee communities can range dramatically in size from 15 to 120 individuals, depending on habitat, available food sources, and reproductive status of females. Extremely territorial, chimpanzees do not take kindly to outsiders infiltrating their communities and will often kill these chimpanzee interlopers.

Population size is defined by a constant ebb and flow—a lot of coming and going occurs in chimpanzee communities. Known as “fission-fusion” societies, individuals will split into smaller subgroups for specific purposes: to forage or hunt, for example. They regroup when the task at hand is accomplished, or to sleep near one another at the end of the day. But it is not uncommon for members of different subgroups to intermingle and then disperse to create new subgroups.

Although chimpanzee communities might be loosely structured by population, they are led by an alpha male. These dominant males are not necessarily the strongest males in a group, however. Rather than lead by might, these intuitive individuals lead by persuasion. Convincing members of his group, particularly the females, of his leadership abilities secures a male the role as alpha. One of the alpha male’s main duties is to protect his group’s territory, so enlisting support of other males in the group is crucial, particularly when the alpha is not endowed with great physical strength. However, if an alpha male’s persuasive powers lapse, another male in the group may usurp his power and assume the role.

Female chimpanzees have their own dominance hierarchy within a group, allowing them first access to food and other resources. Their status is not as extreme as the males, however. A dominant female’s offspring inherits the status of her mother.

Communication

Chimpanzees use 30 distinct calls to communicate with one another. The “pant-hoot” is the most common call and is a series of shrieks and roars that can be heard from a distance of 1.25 miles (2 km).

Body language is also important in communication. An alpha male will attempt to intimidate a foe by assuming a “puffed up” appearance, so that his hair stands on end (called piloerection), making him appear larger than his actual size. If this illusion fails to work, he may resort to throwing rocks at his enemy.

To indicate submission, a group’s male chimpanzees will grunt and reach out their hands to the alpha male.

But it is chimpanzees’ facial expressions that perhaps most suggest what’s on their mind. Although these expressions may appear similar to human expression, the intent can be quite different. As example, chimpanzees have flexible lips that when curled apart, resembles a smile. Unlike a human smile, however, a chimpanzee “smile” signifies fear or anger.

Reproduction and Family

Male chimpanzees may fight one another for the opportunity to mate with a female. Courtship skills include shaking a branch before an ovulating female as an invitation to copulate. Usually, she will grant this privilege to the group’s alpha male. Once she becomes pregnant, however, the male has nothing to do with the baby or mother (a less-than-flattering comparison to deadbeat dads of the human kingdom).

Females reach reproductive age at 13; males are not considered adults until they are 16 years old.

Breeding occurs throughout the year, with a female’s pregnancy lasting between 7.5 and 8 months. She usually gives birth to a single infant, but will occasionally give birth to twins, every 5 to 6 years. Infants will cling to their mother’s tummy and later ride on her back until the age of two. They are considered weaned at 3.5 to 4.5 years; however, they remain dependent upon their mothers until the age of 10.

During this time, moms impart various life lessons to their offspring, such as what foods to eat, how to fashion and use tools, how to build their nightly nests, and how to avoid leopards and other predators that include certain species of large snakes. This period is also a time when young chimpanzees develop their social skills through play wrestling and grooming with other juveniles.

Male chimpanzees typically spend their entire lives within their birth community in the hopes of one day becoming the alpha. Females, however, more often disperse and join different communities.

Ecological Role

Like many fruit-eaters, chimpanzees play a special role in their environment as seed dispersers. Chimpanzees consume the fruit and defecate the seeds elsewhere in the forest. The seeds are allowed to grow into trees without having to compete with their parents for resources. Chimpanzees are capable of eating far larger seeds than most animals in their ecosystem, and many plant species depend on large animals such as chimps to spread their genes and prosper.

Conservation Status and Threats

The International Union for Conservation of Nature classifies the common chimpanzee as Endangered (IUCN, 2016), appearing on the IUCN’s Red List of Threatened Species.  

The western chimpanzee is classified as Critically Endangered (IUCN, 2016), appearing on the IUCN Red List of Threatened Species. They have already become extinct in Gambia, Burkina Faso, Benin, and Togo.

Long hunted for their flesh, known as bushmeat, an even greater threat to the species’ survival is habitat loss through deforestation. Chimpanzees are also susceptible to diseases, like Ebola. And thousands of babies have been captured from their mothers (their mothers are killed to facilitate the capture) to supply the illegal pet trade, rendering a detrimental toll on the population.

Today as few as 100,000 individuals remain in Africa; the population has declined rapidly over the past 30 years. With deforestation continuing, chimpanzees are being forced into smaller, fragmented, isolated regions. Without the forests, there will be no chimpanzees.

Conservation Efforts

Awareness, education, working with local communities and law enforcement agents to preserve habitat and end the illegal commercial bushmeat trade, and the construction of sanctuaries—including those built to accept chimpanzees who have been “retired” from biomedical research or entertainment—are necessary to ensure that these great apes do not disappear from our world, and from our consciousness.

Several world organizations are dedicated to primate conservation.

The Jane Goodall Institute, eponymously named and founded by the famed primatologist, continues to be at the forefront of primate protection. The organization’s Roots & Shoots program equips a global network of youth to become “agents of community change” for habitat and species conservation. The Wild Chimpanzee Foundation is another organization, dedicated to enhancing the survival of the remaining wild chimpanzee populations and their habitat.

Chimpanzee sanctuaries offering retirement to captive chimpanzees include the Fauna Foundation (Quebec, Canada), Save the Chimps (Florida), the Center for Great Apes (Florida), Chimp Haven (Louisiana), and Chimpanzee Sanctuary Northwest (Washington state).

Tchimpounga Chimpanzee Rehabilitation Center is the largest chimpanzee sanctuary in Africa. Located in Republic of Congo, the sanctuary provides a safe home for chimpanzees rescued from the black market.

Liberia Chimpanzee Rescue and Protection (LCRP) is the first and only chimpanzee sanctuary in Liberia, rescuing Liberia’s captive chimpanzees today, and driving change for tomorrow. LCRP currently cares for almost 40 chimpanzees, most of whom are under five years old—and given this chance at a healthy and happy life, will live up to 60 years in the sanctuary’s care. All of LCRP’s chimpanzee family members are orphans whose mothers and other family members were killed to be eaten; the young chimps were kept alive to be sold into the local and international pet trade. LCRP is a Liberian NGO, collaborating with local and international partners in caring for current chimpanzee residents and the development of long term strategies to combat the illegal trade of chimpanzees and other protected wildlife.

And of course, New England Primate Conservancy (NEPC) is committed to saving the world’s chimpanzees and other primates by “leaving a legacy of hope and tools to build a better tomorrow for all the Earth’s citizens.” Through humane education and outreach, NEPC raises awareness about the needs for primate protection, for those captive and wild. 

References:
  • http://www.nationalgeographic.com/animals/mammals/c/chimpanzee/
  • http://www.rainforestanimals.net/rainforestanimal/commonchimpanzeehtml
  • http://wwf.panda.org/what_we_do/endangered_species/great_apes/chimpanzees/
  • https://a-z-animals.com/animals/chimpanzee/
  • http://www.conservenature.org/learn_about_wildlife/chimpanzees/chimp_community.htm
  • http://gainweightjournal.com/insights-on-leadership-from-chimp-alpha-male-behavior/
  • https://janegoodall.ca/our-work/chimpanzee-protection/
  • https://janegoodall.ca/our-work/chimpanzee-protection/tchimpounga-chimpanzee-rehabilitation-center/
  • http://www.savethechimps.org/about-us/chimp-facts/?gclid=CLrbzqrb9NECFc-Eswod1pcOjA
  • http://pin.primate.wisc.edu/factsheets/entry/chimpanzee
  • http://www.iucnredlist.org/details/15933/0
  • http://www-bcf.usc.edu/~stanford/chimphunt/
  • https://www.chimpsanctuarynw.org/
  • http://www.chimphaven.org/
  • https://faunafoundation.org/

Written by Kathleen Downey, February 2017. Conservation Status updated summer 2018.