FURUICHI Takehsi Maize Gakuin University, Assistant Professor, 教養, 助教授 (20212194)
ASATO Ryu Ryukyu University, Lecturer, 医, 講師 (60045052)
YAMAGIWA Juichi Kyoto University, Primate Research Institute, Research Assistant, 霊長類研究所, 助手 (60166600)
KURODA Suehisa Shiga University, Professor, 人間文化, 教授 (80153419)
ENOMOTO Tomoo Toukai University, Assistant Professor, 医, 助教授 (80056316)
KANAMORI Masaomi Aich Education University, Professor, 生物, 教授 (70015585)
|Budget Amount *help
¥22,700,000 (Direct Cost: ¥22,700,000)
Fiscal Year 1995: ¥11,100,000 (Direct Cost: ¥11,100,000)
Fiscal Year 1994: ¥11,600,000 (Direct Cost: ¥11,600,000)
Ecological surveys were conducted in the tropical rain forest, Gabon, and in the savanna woodland, Tanzania. Those study areas include the two poles habitats of Chimpanzees (dry to wet, and abundant to poor food supply). both African great apes : Chimpanzee and Gorilla, sympatorically inhabit the forest in Gabon Ecological environment of each study area was estimated, on the basis of vegetation survey using linetransect method, and the distribution of rodents. The total of 400 plant specimen and 200 samples of rodents were collected and identified. Based on bed census, population densities were, calculated. Data on feces, food traces and behaviors were obtained, to consider intra-species variation of Chimpanzees and inter-species difference between Chimpanzees and Gorillas.
The results show that the both apes in the tropical rain forest, Gabon, depend on fruits and leaves in the coast-line forest. Chimpanzees and Gorillas have more than 80% common food items. Population density of Chimp
anzees was 0.57 individuals/km_2, and that of Gorillas was 0.32. In the savanna woodland, Tanzania, population density of Chimpanzee was less than 0.15, because of extremely poor food supply. Chimpanzees in this area did not eat only fruits in the river-line forest, but fruits and herb in the savanna woodland.
Ethological survey was also conducted in Karinzu and Kibale forests, Uganda. An ethogram of play behaviors among infant Chimpanzees was made, based on focal animal sampling method, to consider intra-species variation of Chimpanzees' behavior in that two study areas.
Those studies indicate that, sympatoric Chimpanzees and Gorillas had common features in food items. On the other hand, Chimpanzees in different environmental habitats, showed wide intra-species variation in food items, population densities, and behaviors. However, it remains uncertain and interesting what factors inference the difference between Chimpanzees and Gorillas. Further studies are needed to understand ecological and ethological aspect of these great apes. Less