“Every square kilometer of forest that is logged represents the
loss of habitat for one ape…once lost, the forest does not return.”*

Until recent times, 25 of Africa’s countries had Chimpanzee populations within their borders. Today, Chimpanzees are found in only 21 African countries, from the west coast of the continent to as far east as western Uganda, Rwanda, Burundi, and Tanzania. Chimpanzees are found in secondary re-growth forests, open woodlands, bamboo forests, swamp forests, and even open savanna with bands of riverine forest and forest savanna mosaic. In these areas they seldom venture far into the savanna except to move from one forest patch to the next.

The greatest concentration of chimpanzee populations is found in the rain forest areas on what used to be called the equatorial forest "belt" – stretching across Central Africa. Unfortunately, the rapid deforestation in Africa has eliminated the belt, leaving only fragmented patches of forest where it once stretched. However, chimpanzees are quite adaptable and have been able to move out into arid areas such as southwest Tanzania and Senegal.

Large Mammals' Crucial Role in Forest Regeneration

The bushmeat trade sets limits on the forests' ability to regenerate itself, as larger mammals such as primates and elephants are among the most important agents of seed dispersal within forest ecosystems. Fruit and seeds compose a large percentage of the primate diet. The dispersal of seeds from the plants that they consume may depend on the passage of seeds through their digestive systems and subsequent deposition elsewhere. Due to the large amount of fruit and seeds primates eat and the large distances across which they range, it is thought that the disappearance of these species will ultimately have a devastating impact on biodiversity and local livelihoods. For example, Gorillas are able to swallow the large seeds of the Moabi tree which is a valuable source of fruit, cooking oil, medicine, and wood within Cameroon. Therefore, if it weren’t for larger species such as the gorilla, the Moabi tree may no longer exist.

Ape populations are estimated to be declining in approximately 96 percent of the protected areas where ape research projects are currently conducted. This is an important indicator as these areas are where ape populations are supposed to receive the most protection. Outside of protected areas, forests are being lost at unsustainable rates to logging and agriculture. As forests are cut down, more and more species have to live in fragmented “island” habitats. This kind of isolation often causes demographic problems for chimpanzee populations and for other species that are dependent on unfragmented habitats. As chimpanzee populations are forced to move into island habitat areas, declines in population numbers will ultimately occur due to the carrying capacity of the area. This decline may be further accelerated due to the fact that as populations become smaller they become more inherently at risk to random events such as disease, environmental catastrophes, and genetic mutations.

The maintenance of forest corridors is essential if primates are to survive in the long term in fragmented areas. The Jane Goodall Institute is currently addressing this issue in Tanzania by working toward raising the protection status of additional chimpanzee habitats outside of Gombe National Park. We hope to connect to the park to those areas as a means to improve the long-term viability of chimpanzee populations in the region.

Project Links:
Tchimpounga Reserve
TACARE
Gombe Stream Research Center
Uganda Chimpanzee Census

*[Marshall, A.J., Holland Jones, J., and Wrangham, R. (2000). “The Plight of the Apes: A Global Survey of Great Ape Populations”. A briefing prepared for representatives George Miller & Jim Saxton. p.16.]