Much of the Kona Forest Unit includes native mesic forest dominated by `ohi`a and koa trees with an understory of tree ferns and other native flora. The refuge is home to four other endangered forest birds: Hawaii creeper, `akiapola`au, the Hawaiian hawk or `io, the `alala, and a number of endangered plants also occur here.
The last remaining wild population of the endangered Hawaiian crow is currently found in the central core of this area.
