Gombe Stream National Park
|Mahale Mountains National Park|
This Park lies 120 kms south of Kigoma, on a peninsula that juts out into the lake. Its center is at about 60 15' S 290 55' E. The Park covers an area of 1,613 sq km (623 sq miles), about 30 times as large as Gombe. Its western boundary protects not only 63 kms of lakeshore but also the adjacent 1.6 km-wide strip of coastal waters. The terrain is mostly rugged and hilly, dominated by the Mahale Mountain chain that runs roughly from northwest to southeast across the middle of the park. The highest of these peaks rises to 2,462 meters above sea level, thus the range of altitude here is more than twice that of Gombe.
The area is traditionally the home of the Batongwe and Waholoholo tribes, but has probably never supported great numbers of people. Since 1961, Japanese primate researcher Junichiro Itani and his colleagues had been exploring the coastline south of Kigoma, and in 1965 Toshisada Nishida established the first research camp in the Mahale area, at Kansyana, and began habituating chimpanzees. Research has continued ever since, and in 1980 the area was gazetted as a National Park.
Temperature and rainfall resemble those at Gombe, but the high mountain range influences local climate. The western slope of the mountains gets more rain than elsewhere. For example, at Bilenge, to the north of the mountains, average annual rainfall is 1,400 mm, while Kansyana, west of the mountains, receives 1,870 mm. This may be why miombo woodland grows at Bilenge while lowland forest grows around Kansyana.
Miombo woodland (mostly Brachystegia, Isoberlinia, and Julbernardia species) covers about three-quarters of the Park, with narrow strips of riverine forest restricted to watercourses. But the mountain range affects vegetation as it affects climate. Where the mountain chain converges with the lake, there is a broad blanket of lowland forest up to about 1,300 meters, similar to the Gombe forest but containing even more trees. Above 1,800 meters, there is a mixture of bamboo bushland and montane forest, neither of which occurs at Gombe. The montane forest includes trees such as Podocarpus, Bersama, Macaranga, and Croton megalocarpus, which live in similar forests on Kilimanjaro, Mt. Meru, and Ngorongoro. Above 2,300 meters the forests give way to montane grassland.
The Park is bigger and its habitats more varied than Gombe, which means that more mammal species live here. In the eastern woodlands are elephants, warthogs, giraffes, zebras, roan antelopes, and buffaloes, and their predators, such as spotted hyenas, wild dogs, and lions. Sometimes the latter hunt in the forest as well; lions are known to have killed several chimpanzees, and wild dogs have been seen hunting a bushbuck on the lake shore. In the lowland forests live a few mammals more typical of West Africa, e.g. the Brush-tailed Porcupine and the Giant Forest Squirrel.
All the primate species found at Gombe are also here, except that the Mahale baboons are of the yellow race instead of olive. In addition, Mahale has black-and-white colobus monkeys, which are here restricted to the montane forest belt above 2,000 m.
The Park may have up to 700 chimps, in about 15 communities, but research has focused on two communities in the northwest of the Park. In their social organization and behavior, they closely resemble the chimpanzees of Gombe, but there are interesting ''cultural" differences as well, particularly in diet. Mahale is richer than Gombe in the number of plant species that occur and that are eaten by chimps, but of the food species occurring in both places, only about 60 percent is eaten by both populations. One major difference is that Gombe chimps rely heavily on palm nuts, but Mahale chimps eat no part of the palm tree. There are also differences in tool use. Gombe chimps often probe for termites but not tree-ants, whereas the best-known Mahale chimps (M-group) probe for tree-ants, but not for termites.
There are some differences too in social behavior. Mahale chimps, when grooming mutually, often groom the partner with one hand while using the other to clasp the partner's hand overheadsomething that Gombe chimps do not do. Also, during courtship a Mahale male may pick a leaf and tear off bits of it with his lips, while trying to attract the female's attention; again, this is not seen at Gombe.
Details mentioned in this article were accurate at the time of publication