Arunachal Pradesh harbors some of the largest tracts of evergreen forests in north-east India. These virgin forests are home to five species of hornbills — the Brown Hornbill Anorrhinus austeni (restricted to the lowland forests of eastern Arunachal Pradesh), Oriental Pied Hornbill Anthracoceros albirostris (widely distributed in the secondary and riparian forests of lowland Arunachal Pradesh), Wreathed Hornbill Aceros undulatus (occupying the low- and mid-elevation forests in the state), the Globally Threatened Rufous-necked Hornbill Aceros nipalensis (found in the mid elevation forests up to around 2000 m elevation) and the Near Threatened Great Hornbill Buceros bicornis (found in low and mid-elevation forests in the state). All the five species of hornbills occur in varying body sizes with the Brown Hornbill being the smallest and the Great Hornbill being the largest. All are predominantly frugivorous birds and occasionally add animal protein in the diet particularly in the breeding season. Hornbills form an important part of local folklore and traditions in Arunachal Pradesh. Various body parts like the casque, tail and primary feathers and meat especially of the Great Hornbill form an important part of the local traditions of tribes such as the Nishis, Wanchos and Tangsas. The impact of hunting on hornbills is still poorly known in the state. In addition, the growing human population and associated habitat degradation also poses a threat to hornbills. Studies addressing these issues in the area have been rare. Our current knowledge on the ecology of hornbills also comes from a single study conducted in western Arunachal Pradesh.
Currently, most of the available information on Asian Hornbills comes from studies that have been carried out at single relatively small spatial scales. In this study, we plan to understand the patterns of distribution and abundance of five species of hornbills at multiple spatial scales. At the smallest scale, an attempt will be made to understand the influence of local scale factors such as distribution and availability of preferred food resources of hornbills (over space and time) and presence of larger and dominant competitors on distribution and abundance of each of the five species of hornbills. At intermediate spatial scales, an attempt will be made to understand the influence of the distribution and abundance of the preferred food plant species of hornbills along the elevation gradient on governing elevational range limits of the five species of hornbills. Finally, an understanding of the factors governing the distributions of five species of hornbills across the entire stretch of Indian portion of Eastern Himalayas will be sought. This would basically involve a state wide survey where information will also be collected to understand the relative influences of hunting and habitat degradation on hornbills.