Introduction
Few records do exist of the avifaunal distribution in Tripura. With an objective to explore the distribution of aves in the rich biodiversity hotspot regions of Tripura, Inventorization Projects were initiated by the Forest Department of Tripura in 34 designated sites (Biodiversity Hotspot areas) of the State. The final phase of this major project was localized into 8 (eight) hotspot regions of the state.
Methodology
The bird team used Point Count Method along specified 3 km transects (wherever a linear distance of 3 km was available for survey) to assess the diversity of birds. A point count was taken every 250 m with a radius of 30 m from the observer for a period of 5 minutes. GPS locations of each point were noted and birds were observed through field binoculars (10” X 50”). Whenever birds were sighted, name of species, number of individuals and sighting distance were recorded. Field guide books like Grimmet et al, 2009 were used to identify the birds. The data sheet was prepared with certain parameters like date, place, starting time, ending time, habitat type, sky condition (clear, cloudy) and wind velocity (light, moderate, windy, stormy). The study was conducted within three hours after sunrise or within three hours before sunset. To build up a checklist in addition to point count data, other bird species that were recorded were listed.
Study Sites and Findings in Each Site
The present study was done in 8 hotspots among the 34 hotspots listed to assess the biodiversity of birds in Tripura. This included Kurti Hoar, Satramia Hoar, Gomti River System, Harijala, Kalapania, Khowai River System, Central Catchment Area and Mayungdwai.
1. Kurti Hoar
The area was seen flooded from all sites and human settlement. However, water dries up in winter. There is no wildlife in this area at all. The area was once forested area but lost all the forest with time. The area is bordered by Assam and Bangladesh.
2. Satramia Hoar
The area is a wetland with paddy fields. The area is also quiet near to Bangladesh. Lesser Adjutant Leptotilus javanicus a threatened bird was seen along with a flock of Asian Openbill.
3. Gomti River System
A beautiful river flows through the reserve forest. However, the border of the forest is almost degraded with small patches of forest. The inner portion of the forest is quiet dense. We covered the area along with boat survey in Gumti River (N23° 25' 30.2" E91° 49' 22.7"- N23° 25’17.3’’ E91° 48’ 04.6’’ ) . Opportunist surveys were made along forest trail to encounter much forest birds. Lesser-necklaced Laughingthrush Garrulax monileger, Red-headed Trogon Harpactes erythrocephalus are some of the important species sighted in this area.
4. Harijala
There area has a big lake and human settlement from all sites and due to this nothing interesting was recorded from this locality.
5. Kalapania
This area is altogether completed degraded with very small patches of forest left. The area has few wetlands and species like Cotton Teal Nettapus coromandelianus was recorded in two areas. A flock of Greater Necklaced Laughingthrush Garrulax pectoralis was seen near human settlement.
6. Mayungdwai.
It is basically an elephant reserve. The foothills are degraded and paddy fields. However, the hill has some forest left. Some part of Mayongdwai is undisturbed by human. Important sighting includes Grey-faced Leaf-Warbler Phylloscopus maculipennis, Silver-breasted Broadbill Psarisomus dalhousiae, Black Baza Aviceda leuphotes. Greater Necklased Laughingthrush Garrulax pectoralis was seen few times.