Our closest relatives

Whether gorillas, orang-utans or bonobos: Take a thrilling journey into the world of the apes – and observe the turbulent life of gorilla matriarch Kissa and her young baby Kiano or female orang-utan Cori.

Plenty of room for swinging

Nine large and small types of monkey have found their home in the Urwaldhaus, which opened in 1985. Many of them are threatened with extinction in the wild. Here, they can swing around in their extensive enclosures in their natural family groups. Animal communities with different species and feed boxes mean our closest relatives never get bored. Glass-covered corridors give all animals the option of using the large outdoor facilities. The exotic trees and planting design create a tropical primeval forest atmosphere.

Bonobos live in the rain forests of the Congo basin. They were recognized as a separate species in 1933, having previously been considered "normal" chimpanzees. However, they differ in many physical features, being more long-limbed and slender than chimpanzees. There are also differences in their behaviour.

Bonobos live in communities of 50-120 animals in an area of approximately 100 km². The members of a community know each other well, but do not live together all the time. Some animals meet for several hours and then go their separate ways. Such a form of interaction is called a fission-fusion system. It has developed as way of adjusting to the irregular food supply, as their main source of nutrition – fruit - is only ever available in small quantities.

The females leave the community and join other communities. The males often have close ties to their mothers and remain near them for life. New, fixed ties are built between the migrating, non-related females. In the case of conflicts over food or partners, the females are often superior to males, but tensions are rarely acted out aggressively. Instead, they are "mitigated" via sexual contacts. For partners who come and go, sex is a suitable tool for peaceful coexistence.

System: Primates, large apes

Distribution: Congo basin

Habitat: Rain forests

Gestation: approx. 8 months

Body weight: 30 kg (f), 40 kg (m)

Population in the wild: a few thousand, threatened with extinction

Population in European Zoos: approx. 70

Food: Fruit, leaves, insects

Gorillas are the heaviest apes with a body weight of approx. 100 kg for females and up to 275 kg for males. They spend most of their time on the ground where they search for food. Gorillas are exclusively vegetarian. They eat herbaceous plants, stems, saplings and shoots. This diet is very rich in fibre, but often low in nutrients. Gorillas must therefore eat large quantities, which keeps them busy throughout the day. In between, however, they require longer periods of rest for digestion.

Gorillas lives in harem groups, consisting of a mature male and several females with their young offspring. The members of a harem group rarely have physical contact. Older males have a silvery-grey back and an impressive appearance. In contrast to their "King-Kong image", which was a fictional creation of the film industry, gorillas shy away from conflict. Although they would be able to cause significant injuries due to the strength of their jaw and their powerful bodies, they avoid fighting where possible.

Primates are characterised by a long childhood and youth. In the case of the great apes, this is about half as long as in humans, but still very long for a primate. This time is particularly important for the animals. Since the brain and nerve structures are still very flexible, they can acquire a lot of essential information for their survival. As young gorillas are also helpless during this time of learning, they need a social environment with stable relationships, rather like human children. The ties to the mother are very close during this period.

Gorilla gorilla gorilla | Lowland Gorilla

System: Primates, large apes

Distribution: Nigeria, Cameroon, Congo

Habitat: tropical rain forests

Gestation: approx. 8.5 months

Body weight: approx. 75 kg (f), 140 - 170 kg (m)

Food: Plants, shoots, leaves

Population in the wild: a few thousand, threatened with extinction

Orang-utans are tree-dwellers in the tropical rainforest. There are two types on the Indonesian islands: Borneo Orang-Utans and Sumatra Orang-Utans. They are the only great apes outside of Africa.

Orang-utans are solitary in the wild. You often find just one orang-utan in one square kilometre. Only the females and their young live together with their offspring, sometimes also accompanied by other mothers with their offspring. However, several animals occasionally meet at good fruit trees, when they spend some time together while they eat before going their separate ways.

Orang-utans are particularly skilled at manipulating objects. Like chimpanzees, they also use various objects as tools. They have been observed in the wild using branches as a fly swat or as a scratching stick. Sticks are used to extract insects or to remove the stones from some fruits, while leaves are used as gloves when handling prickly fruits or branches. Leafy twigs are used to catch and drink water.

Orang-utans also show a variety of tool uses in zoos. In order to promote these behaviours, the keepers keep the animals busy with different materials. For example, they provide grain feed in closed rubber tubes, so that it can only be extracted by shaking or by prodding a stick through a number of small holes.

Pongo pygmaeus | Bornean Orang-Utan

System: Primates, large apes

Distribution: Borneo

Habitat: tropical rainforest

Gestation: 7.5 - 9 months

Body weight: 35 - 45 kg (f), 80 - 90 kg (m)

Population in the wild: a few thousand, threatened with extinction

Population in European zoos: approx. 160

Food: Fruits, young leaves, insects