About Chimpanzeees
Chimpanzees are among the most-studied species in the world. Field studies of wild chimpanzees date back to the 1950s. From these studies and investigations from captive chimpanzees, a lot of information has been gained on chimpanzee biology and behavior. To learn more about chimpanzees, click on the different categories below.
TaxonomySuborder: Haplorrhini
Other species that belong to the Family Hominidae include gorillas, orangutans, bonobos and human beings.
Physical characteristicsChimpanzees have black hair and pinkish to black skin on their faces, ears, palms of their hands and soles of their feet. Infants have pale skin in these areas and a white tail tuft, which disappears by early adulthood. Older individuals sometimes have a gray back and both males and females often have short, white beards. Chimpanzees walk on all fours, or quadrupedally, on the ground and in the trees. They use their knuckles for support while walking on all fours and are called “knuckle-walkers.” This form of locomotion gives chimpanzees longer arms than legs. They can use these long arms to reach out to fruits growing on thin branches that would not usually support the chimpanzees' weight. They can also swing from branch to branch, which is also known as brachiating. Chimpanzees are both terrestrial (ground dwelling) and arboreal (tree dwelling). They travel most on the ground but feed in the trees during the day. All chimpanzees build sleeping nests in trees at night. Chimpanzees have opposable thumbs just like humans do, but they are much shorter than human thumbs. Chimpanzees also have opposable big toes that allow them to have a precision grip and easily climb trees. Chimpanzee males are larger and heavier than females. On average, males weigh between 90 and 130 pounds (40 to 60 kilograms) and females weigh between 70 and 100 pounds (32 to 47 kilograms). Chimpanzees share 95 to 98 percent of the same DNA as humans. Biologically, chimpanzees are more closely related to humans than they are to gorillas.
Range and HabitatRange Chimpanzees have a broad but discontinuous distribution in equatorial Africa. They are found in 21 countries, from Senegal in the west to as far east as Tanzania.
Habitat Because of their broad distributions, chimpanzees live in a variety of habitats. They live in the greatest concentrations in the rain forest areas in what was once called the equatorial forest belt. Due to rapid deforestation, the belt has been eliminated, and now only fragmented patches of forest exist. Chimpanzees are able to move into other habitats including secondary re-growth forests, open woodlands, swamp forests, bamboo forests and open savanna.
DietThe chimpanzee diet consists mainly of fruit, and a chimpanzee may spend up to 78% of its feeding time eating fruit pulp. Chimpanzees are considered to be highly specialized frugivores and prefer to eat fruit even when it is not abundant. In addition to eating fruit, chimpanzees also feed on leaves, seeds, pith, bark, stems and blossoms. They also supplement their mainly vegetarian diet with insects, birds and birds’ eggs; they even hunt and kill smaller mammals for meat. Their most common prey is the red colobus monkey (pictured). Other prey items include blue duikers, bushbucks, red-tailed monkeys, yellow baboons and warthogs. Chimpanzees spend about 40-60% of their active time feeding and a lot of time moving from one food source to another.
Social Structure and BehaviorChimpanzees are characterized by multi-male, multi-female fission-fusion groups ranging from 20 to 150 individuals. A fission-fusion society consists of a large community that is broken up into smaller, temporary subgroups. These subgroups can contain any number of individuals (up to a few hundred) and are always changing in size and composition. Males have a stable dominance hierarchy and are dominant over females. Males also remain in their natal communities while females, in general, emigrate at adolescence, when they are between 9 and 14 years old. While males within the same group are highly gregarious, females live a more solitary life, spending 65% of their time alone with their offspring within a core area. Young chimpanzees are reliant on their mothers for a long period of time. During their first year, chimpanzees are in constant physical contact with their mothers. They will venture a small distance from their mothers at around 2 years of age and are weaned by their mothers between the ages of 4 and 6. Chimpanzees become independent between 6 and 9 years of age. Although at this age they become much more independent, chimpanzees will have lifelong bonds with their mothers. Reproduction Data from wild chimpanzees indicate that females reach sexual maturity at approximately age 11 while males do not reach sexual maturity until age 13. When a female is in estrus (i.e., sexually attractive and receptive to the males), the skin around her rump swells considerably and is clear pink. Females show their first small sexual swellings at age 8 or 9, but there is usually a two-year period of adolescent sterility before the female conceives. Spacing between births (provided the previous infant lives) is about 5 years. The gestation period is approximately 8 months, and the average age for the female's first birth is 14 to 15 years.
LifespanThe average lifespan of a wild chimpanzee is 40 to 45 years. Chimpanzees in captivity live longer than wild chimpanzees and can live up to 60 years or more. To find out more about the oldest chimpanzees living in AZA accredited zoological parks and the Chimpanzee Species Survival Plan (SSP) visit the Chimpanzee SSP website.
Tool-useIn 1960, primatologist Jane Goodall discovered that chimpanzees at Gombe National Park in Tanzania made and used tools to extract termites from a termite mound. This discovery was a breakthrough because it was the first example of tool-use in animals. Until that time scientists thought that humans, and only humans, used and made tools. Dr. Goodall named this behavior as termite fishing and described it as a behavior in which individual chimpanzees fashion pieces of vegetation into the appropriate size to puncture a termite mound and extract the termites that cling to the tool. Eventually it was discovered that the Gombe chimpanzees use objects – stems, twigs, branches, leaves and rocks – in nine different ways to accomplish tasks associated with feeding, drinking, cleaning themselves, conflict (e.g., flailing branches and throwing rocks as missiles) and investigating out-of-reach objects. Chimpanzees are considered to be the most prolific tool users among the non-human primates. They have a vast tool repertoire that varies across geographic ranges, genetic populations and ecological systems. In chimpanzee communities outside Gombe National Park, chimpanzees use objects for different purposes, including cracking nuts and sponging water to drink. These behaviors are passed from one generation to the next through observational learning and can be regarded as primitive cultures.
Threats and conservationThe IUCN/World Conservation Union Red List of Threatened Species lists that each of the species of African great apes – chimpanzees, gorillas and bonobos – as endangered. Chimpanzees have gone extinct in 4 of their 25 range countries (Gambia, Burkina Faso, Togo and Benin). Today, researchers roughly estimate the wild population of chimpanzees to be between 172,000 and 300,000 individuals. This is in stark contrast to the perhaps 1 million chimpanzees that inhabited equatorial Africa at the turn of the 20th century. The biggest threats to great apes are habitat loss, commercial bushmeat and illegal exotic pet trades, and infectious diseases. Habitat loss is a result of the conversion of land for agriculture and competition for limited natural resources, such as firewood. This, in addition to commercial logging and mining, has left small and unconnected patches of chimpanzee habitat. These patches leave chimpanzee populations isolated and vulnerable. Commercial logging and mining also creates roads through remote forests, increasing accessibility of hunters into once inaccessible forests. Adult chimpanzees are hunted to be sold as bushmeat and, although the pet trade is illegal in all range countries, orphaned infants are sold into the illegal exotic pet trade industry. The main cause of death in chimpanzees at Gombe, Mahale and Taï National Parks is infectious disease. Chimpanzees are so similar to humans that they contract many of the same diseases that afflict humans. As human populations increase, the frequency of encounters between chimpanzees and humans also increases, leading to higher risks of disease transmission between humans and chimpanzees. In the past 15 years, Ebola fever has killed chimpanzees in Côte d’Ivoire, and repeated epidemics have caused dramatic declines of ape populations in remote protected areas in Gabon and the Republic of Congo. Current trends show that African ape populations will decline an additional 80% in the next 30 to 40 years. This means that we have about a generation and a half to correct the trend or these magnificent creatures will become extinct.
Intelligence and cognitionChimpanzees are highly intelligent primates. They can manipulate situations to achieve desired outcomes using a variety of problem-solving methods. They use facial expressions, vocalizations, touch, and body language to communicate with members of their group. Chimpanzees constantly monitor the faces of other members of the group to discover their moods and intentions. Scientists studying chimpanzees have identified 32 different calls that are versions of four call types: grunts, barks, screams, and hoots. Chimpanzees use different vocalizations and gestures to convey a wide range of emotions from grief, anger, and fear to happiness, excitement, and puzzlement. For instance, when reunited after a separation, chimpanzees may greet each other with pants, touches, open-mouthed kisses, or a bout of play. They are also capable of deception. Chimpanzees use their ability to communicate effectively to develop sophisticated hunting strategies involving group cooperation. The males will hunt monkeys and small mammals in cooperative groups of 1-35 individuals. The kill is often shared with friends or allies or as a means to form alliances, gain sexual favors, and convey status. Chimpanzees learn to create tools from objects in their environment by watching others. For example, they use sticks to extract termites to eat and crumple leaves to soak up water to drink. Jane Goodall was the first researcher to discover that chimpanzees make and use tools when she observed a chimpanzee strip a stem of its leaves and use the stem to “fish” for termites. Since that groundbreaking discovery, chimpanzees all over Africa have been observed making and using tools in a wide variety of situations. Besides fishing for termites, chimpanzees use rocks as hammers and anvils to pound open nuts, leaves as napkins and sponges, and sticks to probe or break open beehives for honey. Some groups manufacture spears to kill small mammals. Other chimpanzee populations even have “tool kits,” a collection of different tools used in sequence to access a particular food source. It can take chimpanzees years to perfect their use of tools, as many as five years to learn how to fish for termites, ten years to learn how to pound open palm nuts with stone hammers and anvils. Tool use gets taught and passed down from generation to generation. There have even been archaeological discoveries of stone tools used by chimpanzees over 4,000 years ago, similar to stone tools used by chimpanzees today to crack open nuts. Many of the tools that chimpanzees construct and use are associated with food. Cognitive tests of memory and self-awareness prove that chimpanzees recognize numerical systems and can spontaneously plan for a future state or event. Current research indicates that chimpanzees have a near photographic memory. When shown a sequence of up to nine numbers for a quarter of a second, they are capable of putting the numbers in the correct place in ascending order. |
Chimpanzees as petsChimpanzees do not make good pets. They cost between $30,000 and $75,000 and annual care can run up to $10,000 a year. Additionally, they can live to be sixty years old in captivity. Chimpanzee infants are appealing because they are irresistibly cute, extremely affectionate, and require 24-hour care and contact from a mother, similar to a human baby. When breeders sell chimpanzees as pets, they are always removed from their own mothers within months of birth so that the human owners can "bond" with their pets and have more control over them at a younger age and smaller size. Pet owners dress them, feed them, and treat them as if they are human children and come to think of them as sons and daughters. When these human-like pets reach puberty, they become extremely strong and aggressive, and develop an intelligent mind of their own. Pet owners lack the space, time, money, and resources to socially and intellectually stimulate adult chimpanzees. Unhappy juvenile and adult pet chimpanzees often become rebellious, violent, and dangerous as they grow in intelligence, strength, and size (130 to over 180 pounds). When owners can no longer properly care for their chimpanzees they must look for alternative housing options. When these ex-pet chimpanzees are sent away to breeders, roadside zoos, or sanctuaries they usually have serious problems integrating into natural chimpanzee social groups. Ex-pet chimpanzees have the most trouble interacting with their own species when they've been raised alone in a home because they have not learned the necessary chimpanzee etiquette to interact with their own species. They often grow neurotic and depressed trying to deal with living with other chimpanzees. Tragically, many pet chimps end up in medical research laboratories or unaccredited roadside zoos. Chimpanzees do not belong in human homes. They can only be owned legally in certain states where wildlife laws permit ownership of non-human primates and wild or exotic animals. The best way to learn more about chimpanzees is to visit accredited zoos, volunteer at accredited sanctuaries, and to support institutions that care for chimpanzees without causing them harm.
LegislationCurrently, there is no federal legislation prohibiting the ownership of chimpanzees. Though many states have banned the use and possession of great apes, the lack of a centralized set of laws regulating non-human primate ownership has resulted in an ineffective patchwork of individual state laws. Ongoing efforts to close the loopholes in the laws protecting chimpanzees are in response to animal welfare grievances and public safety concerns. Recent successes include the introduction of the Captive Primate Safety Act (S. 1324) which would prohibit interstate sale and trade of non-human primates as exotic pets. To learn more about the legal status of chimpanzees, monumental accomplishments in their protection, and the ongoing efforts to change current legislation, visit the following website:
Accredited zoos and Chimpanzee Species Survival Plan (SSP)The Chimpanzee Species Survival Plan (SSP) is charged with the management of the 270 chimpanzees living in AZA accredited zoos across North America. Although the program is involved with population management, they are ultimately interested in the health and wellbeing of ALL chimpanzees, including those living outside accredited zoos and in the wild.
Chimpanzee SanctuariesChimpanzee sanctuaries play a vital role around the world by providing lifetime security and care for chimpanzees in need. Sanctuaries in Home Range Areas (Africa) - PASA In 2000, a group of African sanctuaries joined together to form the Pan African Sanctuary Alliance (PASA). Today, this organization combines the efforts of 20 sanctuaries to care for nearly 1000 rescued chimpanzees, as well as a large number of other endangered primates across Africa. Many of these chimpanzees end up in sanctuaries as orphans as a result of the bushmeat trade and habitat loss/deforestation. Sanctuaries in North America - NAPSA Formed in July of 2010, North American Primate Sanctuary Alliance (NAPSA) consists of 7 sanctuaries across North America: The Center for Great Apes, Chimp Haven, Chimps, Inc., Chimpanzees Sanctuary Northwest, Fauna Foundation, Primate Rescue Center, Inc., and Save the Chimps, Inc. The mission of NAPSA is: “To advance the welfare of captive primates through exceptional sanctuary care, collaboration, and outreach.” The chimpanzees in these sanctuaries come from a diverse set of backgrounds: from biomedical laboratories to a range of privately-owned situations. Due to their diverse backgrounds, accommodating each individual’s personalized needs becomes a large challenge very quickly. Moreover, the cost to care for a chimpanzee over its entire lifetime can be astronomical. These logistical and financial struggles are ever-present challenges to chimpanzee sanctuaries. Interested in getting involved? Here are some resources:
Chimpanzees in researchChimpanzees are often considered our closest non-human relatives due to our genetic relatedness. Consequently, chimpanzees were assumed to be an ideal model for studying human physiology, cognition, and diseases. Chimpanzees have been used in a research context in the US since the 1920s. From Washoe, the sign language chimpanzee, to the famous “astronaut chimpanzees” used by NASA in space exploration research, chimpanzees quickly became very common test subjects. They rapidly became popular in the field of biomedical research, including studies on HIV/AIDS, Hepatitis, and Polio - among many others. Despite their genetic similarities to humans, chimpanzees have a different physiology and react to diseases and viruses differently. After being subjected to numerous medical experiments, it has been widely decided that chimpanzees are not suitable study models. In the case of HIV and AIDS research, some chimpanzees can become HIV positive, but never develop any symptoms of AIDS. Chimpanzee biology alone stands to reason that they are not appropriate for research studies, but there is also a powerful ethical crossroads encountered in the decision to use them in active research. The typical laboratory living conditions prioritize laboratory protocols over the chimpanzees’ psychological, social, and emotional requirements, resulting in long-term trauma. Currently holding more than 1,000 chimpanzees for research, the US is the only developed country in the world to still actively engage in this practice.
Chimpanzees in entertainmentThe presence of chimpanzees in popular media is widely acknowledged and accepted in the United States. They are trained to perform in live stage shows, television productions, movies, advertisements, and circuses. However, many people are unaware that the apes they see are infants and juveniles, taken from their mothers at birth to be trained when they can still be easily controlled. As they age, chimpanzee “actors” become too strong and willful. They may refuse to perform the unnatural behaviors they are trained to do. When chimpanzee “actors” become too old or too unruly, they are discarded and often end up biomedical labs or unaccredited facilities that cannot provide the best possible care. Information about the hardships faced by these animal performers has led many companies to pledge not to use chimpanzee “actors.” This is a first step in protecting the welfare of chimpanzees in captivity. For more information about chimpanzees in the entertainment industry, visit the “Chimpanzees in Entertainment” section of our website:
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