Flora and Fauna of Tirap district is really vast and extensive. Flora of this region like the other districts of the state of Arunachal Pradesh is rich in diversity and extent. The plants of the Tirap district mostly comprise tropical as well as sub-tropical evergreen forests with combined grasslands and moderate forests in the high hills. Most of the wooded areas are of secondary nature due to the frequent destruction of forests by shifting cultivation practiced by the local people. Primary forests are limited to relatively less accessible areas.
Like in all the tropical rain forests, the vegetation in Tirap district too presents a tiered sequence. The forest covering is Golden-Backed Woodpecker by the spreading branches of tall trees of diverse range particularly Diterocarpus Vesque, Terminalia Heurck and Muell. Scattered and less tall trees and other middle-sized species outline the second tier. In somewhat open areas, clusters of the fan-leaved palm Livistonia Kurz, and the fish tailed palm Wallichi Anders can be seen occasionally. Other palms like the slender stemmed Pinanga gracilis the stout, fan-leaved Licuala spinosa and the spiny large-leaved Zalacca Griff also occur. Further, large masses of giant Bamboos are also not infrequent. Large woody climbers, frequently interrelating adjoining trees, entangle the trees and forming entwined garlands of branches hanging loosely from the top. Interestingly, the climbers are chiefly of the families named Menispermaceae, Annonaceae, Vitaceae, Connaraceae and Cucurbitaceae. Amid all these a particularly vicious member is the climbing palm, the cane or Calamus. There are a number of species in these forests, some with heavy stems extending to abnormally long distances, and others with slim stems. These canes are largely used by the local tribal people of Tirap district.
Similarly, like the flora, the fauna of Tirap district is also rich and diverse. It consists of some unusual species of wild animals. The region is frequented by few local Palaearctic species and migratory species of birds that breed around the Sino-Himalaya Mountains area. The resident waterfowls that are commonly found in river waters and pools are the Spotbill Duck, the Comb Duck, the Lesser Whistling Teal, the large Whistling Teal and Cotton Teal. Varieties of birds can be found in the evergreen jungle on the plains and the lower slopes. In the denser part of the forests that has tall trees laden with epiphytes, birds that are usually found are the Fairy Drongos such as the Crowbilled Drongo and the Greater Racket-Tailed Drongo, the Mountain Thrush, the streaked spider hunter, the Lesser Golden-Backed Woodpecker, etc.
The conditions are frequently changing as shifting terrace cultivation is extensively practiced by the people. As a result, may portion of the slopes once covered with intense forests are now covered with dense secondary growth of shrubs, grass interspersed with scattered trees of Bombax, Zizyphus etc. Such secondary shrub jungles are the home of Bulbuls, such the Red Whiskered Bulbul, Babblers, Chats and several species of Warblers, Spotted Dove and Quails, such as the Manipur Bush Quail, the Bustard Quails and the Malabar Pied Hornbill, the Red-headed Trogon, the Malabar Whistling Thrush and the Indian roller. The other birds that are frequently found are the Black-naped Green Woodpecker, Rufousneck Hornbill, Maroon Oriole, Minivets etc. Moreover, the mountain forests of the Tirap district contain some characteristic high altitudinal birds, such as the Common Hill Partridges, Blyth`s Tragopan and more.
During the winter season, migrating birds from Northern Asia have their momentary quarters in this region. Thus, the rich and vast range of flora and fauna of Tirap district is considered as one of the main attractions for the tourists.