The other sanctuary of the chimpanzee, Mahale Mountains National Park, is only reached by charter flight or by boat from Kigoma. Covering an area of approximately 1,600 sq km, the park’s western boundary is the shore of Lake Tanganyika. The chimpanzee population is estimated at around 1,000 and they may be observed in their natural habitat in groups of up to 30. Yellow baboons, red colobus, red-tailed and vervet monkeys alsolive in the park and are commonly seen as are bush-babies, bush-pigs, bushbuck, blue duiker, civet, hyrax and white-tailed mongoose. Buffalo, elephant, giraffe, leopard, lion, porcupine and other various types of antelope are also present but will prove more difficult to find. Lake Tanganyika is home to more than 250 species of fish.