Prof. Dr. Christophe Boesch
Prof. Dr. Christophe Boesch
Phone:+49 341 3550-200/201Fax:+49 341 3550-119

Max-Planck-Institute for Evolutionary Anthropology, Leipzig

Website Christophe Boesch

Dr.  Hjalmar Kühl
Dr. Hjalmar Kühl
Phone:+49 341 3550-236

Max-Planck-Institute for Evolutionary Anthropology

A.P.E.S. - Database

original publications

Jessica Junker et al.
Recent decline in suitable environmental conditions for African great apes
Geneviève Campbell, Hjalmar Kühl, Paul Kouamé N’Goran und Christophe Boesch
Alarming decline of West African chimpanzees in Côte d’Ivoire

Further Links

Less and less room for Africa’s apes

One of the first comprehensive studies covering the entire African continent proves that the habitats of these animals have dramatically dwindled over the past few years. [more]

A.P.E.S. – Database

A comprehensive data archive: In addition to numerous maps and background material, specific data concerning ape populations can be called up. [more]

Manifesto for Apes and nature

Petition for the preservation of apes in their native habitats. [more]

Species protection

Chimpanzees: an endangered species

In the past, it was only possible to provide a rough estimate of the number of chimpanzees still living in the tropical forests and savannahs of Africa. For this reason, field biologists tried to determine the population sizes and their development using more precise methods. Their ultimate aim is to provide effective protection for the animals.

The habitats of the great apes, which include chimpanzees, bonobos, gorillas and orang-utans, have shrunk dramatically in the last 20 years. This was demonstrated for the first time by a study that was commissioned by the International Union for Conservation of Nature (IUCN) and headed by researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig. Records of over 15,000 occurrences of African apes were collated and provide an overview of the remaining habitats. These records were archived in a database (A.P.E.S) and also provide an important tool for species protection.

According to the data, chimpanzees are by far still the most common of the African ape species. Around 150,000 individuals still live in West, Central and East Africa. Unlike the bonobos and gorillas, they can adapt to different habitats. The majority of chimpanzees live in the tropical rain forest; however, they are also found in the more arid woodland savannah (see distribution map). In addition to the clearing of forests to make way for mining and intensive crop farming, illegal hunting and disease pose the greatest threats to the survival of this fascinating ape species.

The chimpanzees have lost over 200,000 square kilometres of habitat over the last 20 years – an area that corresponds to around 3,800 football pitches per day.

The main facts at a glance:


  • Forests are being destroyed by slash-and-burn
  • The main perpetrator here is the timber industry: As the sought-after tropical trees do not grow in groups and are usually dispersed throughout the forests, forestry companies constantly create new paths in the forests and build roads for the removal of the tropical timbers.
  • Agro-industry: Plantations covering thousands of hectares are being created to satisfy the growing demand of industrialised and threshold countries for products from tropical regions like palm oil, rubber, sugar and biofuels. This is further accelerating the destruction of the apes’ habitats.
  • More and more forest area is also being sacrificed in the quest for mineral raw materials: Wherever major deposits are found, ores like aluminium, gold, copper and coltan are mined and oil is extracted.
  • Road construction - despite being largely insignificant in terms of the area it consumes - opens up the forest to settlers. They slash and burn more area, and cultivate cereals and other crops on the deforested land.
  • There is a dramatic increase in poaching in these areas.

The most severely affected regions are the rain forest areas of the Congo basin and the West African coastal forest in Liberia. However, a large proportion of the habitats in other areas, for which such a severe decline has not been reported, had already been destroyed before the 1990s. In particular, the remote central African forest regions, which are still considered the stronghold of the apes, are now criss-crossed by numerous forestry and mining roads and have been populated by humans as a result.


Fewer places to retreat: The protected zones for chimpanzees in East and Central Africa (dark green) and other such areas which, as recommended by the scientists, should be integrated into special action plans (grey). Zoom Image

Fewer places to retreat: The protected zones for chimpanzees in East and Central Africa (dark green) and other such areas which, as recommended by the scientists, should be integrated into special action plans (grey).


Despite the fact that hunting for protected species like apes is illegal everywhere, many animals that live in the forest are hunted for their meat. “It has not even been possible to halt the killing by banning hunting,” says Tobias Deschner, a primatologist at the Max Planck Institute for Evolutionary Anthropology.

The reasons for this are very diverse: several hundred million people live in the regions of Africa in which apes are also widespread. Moreover, the urban populations in Central, East and West Africa are growing by between two and four percent annually. With the rising income of the urban population, the demand for game meat is also increased and it is openly supplied at many markets. It provides a lucrative source of income for the poorer rural populations.

When hunting for antelopes and other game, poachers do not hesitate to shoot chimpanzees and other apes. In this way, the bush game hunters not only decimate the chimpanzee populations, they also increase the risk of the transmission of diseases from chimpanzees to humans. Recent research has shown that the HIV virus, which causes AIDS in humans, probably originates from the chimpanzee. Scientists now believe that this disease could have been transmitted to humans through the trade in game meat.

Infectious deases

Ebola, which is suspected of being transmitted to humans and apes from fruit bats, has taken a heavy toll in the forests of Central Africa over the past ten to 15 years. The disease has claimed many human lives and the chimpanzees and gorilla populations have also been drastically reduced. Ninety percent of the gorillas in an area on the edge of the Odzala National Park in the Republic of the Congo died within a period of a few months due to the infection (Martha Robbins/Christophe Boesch: “Among African Apes”). As there is no vaccination against Ebola, this pernicious disease continues to pose a threat to both humans and animals.

Hunting for apes also increases the risk of introducing human diseases to the ape habitats. Humans have developed antibodies against respiratory and intestinal diseases - however, the apes have not. Diseases of the airways, which take the form of normal colds in humans, often prove fatal in chimpanzees. The risk of transmitting germs can be minimised if scientists and tourists who come into proximity with the animals take precautionary measures.

Large numbers of chimpanzees in the Taï National Park in Côte d’Ivoire have been dying of anthrax for some years now. The scientists try to vaccinate the animals as thoroughly as possible using blowpipes and have thereby managed to keep the levels of infection under control to date.

Cencus in the jungle

In the 1950s, the chimpanzee population in Côte d’Ivoire was estimated for the first time at several tens of thousands of animals. Around 30 years later, when the first national chimpanzee census was carried out, the estimate had to be corrected down to between 8,000 and 12,000 animals. Despite the strong decline in the population recorded at that time, the country remained home to a large number of West African chimpanzees.

As part of a study carried out at the Max Planck Institute for Evolutionary Anthropology in Leipzig, a country-wide chimpanzee census was carried out in 2008. The results were disastrous: the ape researchers now assume that there are only between 1,000 and 2,000 chimpanzees in Côte d’Ivoire. Compared to the survey carried out 17 years earlier, around 90 percent fewer chimpanzee sleeping nests were counted. The population decline was most striking in unprotected forest areas – outside the national park.

However, the survival of chimpanzees in protected areas is also threatened, as soon as the monitoring stops or external funding or support is withdrawn, even temporarily. “Species protection activities can only succeed if long-term funding is guaranteed,” says Christophe Boesch, head of the Max Planck research team.

The researchers had thus assumed that they would find one of Côte d’Ivoire’s largest chimpanzee populations in the Marahoué National Park. However, just a few years after international species protection projects had been put on the back burner due to the political unrest in the country, the park had been appropriated by farmers and has completely disappeared.

“I followed my routes in the Marahoué National Park, just as I had done in classified forests all over the country where I often had to search long and hard to find any original trees at all,” reports Geneviève Campbell, who collected the data. “The really sad thing was that I only found a single chimpanzee sleep nest in this park, where, along the same route, we found 234 nests during the last count.”

A treasure for future generations

The few chimpanzee populations remaining in Côte d’Ivoire are distributed across an extensive area. The only population that may be capable of surviving lives in the Taï National Park, in which the film “Chimpanzees” was filmed. (link to Around 264 animals were recorded there in 2012; however, this population is also under severe threat from poaching.

For this reason, the Wild Chimpanzee Foundation, which was founded by Christophe Boesch, campaigns for the survival of the fascinating apes there and in many other West African countries.

The nature conservation organisation aims to preserve this great treasure of Côte d’Ivoire for future generations. The numerous measures undertaken to achieve this objective include further research, efficient protective measures in the park, for example patrolling by park wardens, and awareness-raising campaigns and development programmes that aim to inform the local population about the importance of saving the animals. Courses on nature study are provided for schoolchildren in the forests, plays are presented and the local people are included in research programmes to make them more aware of the value of the forest.

None of these activities is particularly difficult in itself but it can be very difficult to use them in an effective individually-tailored way, particularly in situations in which poverty is rampant, corruption is widespread, and both schools and funds for development measures are lacking. “The resources available for nature conservation in Africa are highly inadequate,” writes Christophe Boesch in his book “Among African Apes”. “It may sound melodramatic, but we are currently attempting to stop what amounts to a raging fire by splashing a few cupfuls of water on it.”

Barbara Abrell

Image: Disneynature

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