Rain forests consist of layers of vegetation. On the ground there is some leaf material. Sunlight rarely penetrates to this layer. A variety of ground dwelling birds such as the crested fireback pheasant and pittas may be heard and seen along the trails. Above this is the lower story which includes small woody plants, tree saplings, small palms (Arenga sp and Licuala sp) and ferns. The middle layer is home to insects and nectar feeding birds like the Little Spiderhunter. It is composed of the trunks of big trees and the crowns of smaller trees. The upper story or canopy consists of closely joined crowns of the big trees, rattan (Calamus sp) and fan palms (Livistona sp) which are exposed to full sunlight. Here one can see the long-tailed macaques
and leaf monkey.
Bird species include drongos, blue-throated bee eaters, and leafbirds as
well as the magnificent hornbills. Trees which extend above the canopy
are known as emergents; the crowns are not closely joined and they stand
out from the rest of the foliage.
The light colored trunks of the Dipterocarpus and Shorea species as well as the 50 meter tall tualang tree (Koompassia excelsa) fall into this category. These big trees have huge buttressed roots to support their sheer weight.
Woody epiphytes (plants that grow on other plants) such as orchids and stag's horn fern are abundant here. Woody vines called lianas hang from trees to the ground.