Nutrition
Fruit is the main food bonobos eat, though they also eat many other plant parts, such as nuts, stems, shoots, leaves, and roots. Fruit in their range is low in sugar and high in fiber, unlike fruit the fruit we eat. They may also eat termites, grubs, and worms.
At the Zoo, bonobos are offered a variety of fruits and vegetables, a specially formulated primate biscuit, browse, rice, popcorn, oatmeal, and other food enrichment items.
Current Range and Historic Range
Bonobos are found only in a 124,274 square mile area in central Africa, which is about the same size as Great Britain. This area is in the central basin of the Democratic Republic of Congo, south of the Congo River. It includes two river systems that mark the limits of bonobo habitats: the Congo-Zaire-Walaba River and the Kwa-Kasai-Sankuru River. These rivers create natural barriers for the bonobos because they are not known to swim, although they can wade through water that is up to their waists.
Habitat
Bonobos can be found in swamp forests, secondary forests, grasslands and primary forests.
Predators and Threats
It has been speculated that leopards may feed on bonobos. However, humans are the only verified predators of bonobos.
Hunting, capturing, and eating bonobos is illegal, but poaching is still common. People hunt them for their meat or believe their body parts have medicinal purposes. Baby bonobos are often taken in illegal wildlife trade. Even though many bonobos live in national parks and other protected areas, these places usually do not have enough resources or strong law enforcement to keep them safe.
Another significant threat to bonobos is deforestation. Large-scale farming, like palm oil plantations, destroys thousands of acres of forest. Local people also clear land for farming and cut down trees for fuel.
Physical Description and Adaptations
Hair color in bonobos is usually dark black, and they often have dark faces with a pink color around their lips, eyelids, and sometimes on their fingertips and the tips of their toes. Male bonobos have long canine teeth, but females do not. They have long legs, and when they walk on all fours, their backs stay more horizontal because of their elevated hips.
They have a tuft of white hair at the end of their tails that they keep for their whole lives. This tuft can be big in some bonobos and very small in others. Adult female bonobos have large swellings in their genital area that show when they are ready to mate. The size of these swellings can also show their rank in the group; usually, the most dominant female has the biggest swelling.
Reproduction
Bonobos have a polygynandrous mating system, where females can be approached and mate with any unrelated male within their group. They breed throughout the year without a specific breeding season. When female bonobos are ready to mate, their genitals swell, and this swelling lasts for about ten to twenty days. Most mating happens during this time. After mating, the gestation period, or time before giving birth, lasts about seven to eight months. Usually, a single baby bonobo is born, weighing between two and four pounds, but twins can occur, although they are rare.
Baby bonobos depend on their mother's milk and cling to her for several months. The mother takes care of the baby most of the time. As the baby grows and gets a bit older, the mother allows the baby to interact with other members of the group. The mother decides who can visit her baby. All group members, including males, spend time with the young bonobos. Each mother bonobo has her own style of parenting and may let others interact with her baby at different times.
Weaning, or the process where the baby stops drinking milk, starts gradually around the age of four. During this time, mothers often let their younger ones eat alongside them so they can learn about food choices instead of just getting food directly. A mother may also stop her juvenile (young bonobo) from returning to her nest, pushing it to make its own nest. Bonobos usually have a new baby about every five to six years.
When female bonobos reach sexual maturity, usually between the ages of seven and fourteen, they leave their birth group. In contrast, male bonobos stay in their birth group and remain with their mothers for their entire lives.
Communication
Bonobos are the most vocal of the great apes. Their communication is complex. Vocalizations convey important information, such as where food is located, or express a wide range of emotions, like alarm, anger, excitement, satisfaction and more.
Visual communication, such as facial expressions and head bobs, is also used. Bonobos often use physical contact to ease tensions, fears, and disagreements.
Behaviors
Bonobos travel in small groups, usually made up of a few individuals. These groups change often throughout the day as small parties come together to eat, rest, and play. All of these parties are considered part of one large community. At night, members of the bonobo community tend to gather together. This type of changing social structure is called "fission fusion." The size of a bonobo party can vary based on food availability and can range from seven to twenty individuals. Overall, a bonobo community usually has around 25 to 75 members.
A group of bonobos is always led by a dominant female. Females are known to form strong bonds and work together to keep the peace, especially if male members of the group become aggressive. A male's social status is often determined by his mother. Bonobos do not frequently show typical displays that demonstrate dominance or submission. Generally, high status seems to be based on seniority.
Sex plays a very important role in bonobo society. It helps them manage relationships, relieve tension, and build social connections. Bonobos engage in sexual interactions with others in the group, regardless of gender or age.