关键词: 海南长臂猿, 栖息环境, 群落结构, 行为

Abstract: The gibbons of Hainan live mainly on the high trees in tropical valley rain forests and mountain rain forests，and are hard to adapt themselves to other types of forests．There must be enough tropical natural forests to protect gibbons．
The valley and mountain rain forests have vertical structure that the stratification is of more than three layers．The trees are high and have wide range crowns with big xyloid lianas．epipbyte and parasite plants，and have most abundant food resources．Humidity and temperature are most suitable and the conditions are good for gibbons
singing and sleeping．
The wider vallies and slopes of virgin rain forests are major places for activities and shelter for the gibbon groups which prefer to live in the forest area between the middle and lower—middle part of mountains，but go rarely to the forests in the mountain peak and ridge with high altitude．
There are few birds or beasts of prey in the area，and not under threat．With lessening human disturbances and the good condition of natural forests，the gibbon population will increase．It has been proved that the number of the gibbon has been doubled since the Bawangling Nature Rererve on the Hainan Island was Set up．
Though the gibbon population do not have an attachment to the rem nant and secondary forests at present．the gibbons may make use of them after their long- time renewal．

Key words: Black or blackerested gibbon, Habitat environment, Commnunity structure, Behavior