The Socio-Ecological Study of Orangutans and the Forest Conditions after the Big Forest Fires and Drought, 1983, in Kutai National Park, Indonesia

The 1983 forest fires affects on the lifes of orangutans were studyed since 1983 upto 1986 in Kutai national park, East Kalimantan, Indonesia. The burnt and the unburnt areas are illustrated on the maps by the results of the authors surveys. The secondary trees grown up very quickly and reached about 13—15 meters heigh after the fires. The fruits productions have been very low, so orangutans have depended upon at first barks and young leaves of the trees after the fires and then young stems and new buds and leaves of the secondary trees that grownup afterward in 1985 and 1986. Total 18 individuals of orangutans were observed in the study area. The population density is estimated as 1.8 individuals per 1km^<2> in the study area, and roughly estimated as 1 individual per 1km^<2> in all north — easternpart of Kutai national park (A.Suzuki 19-84). Several couples of mothers and infants occupied in their ranges ranges, and several adult males moved widely plural females' ranges. Daily activity patterns were recorded in each individuals