A checklist of avian fauna at Jeypore Reserve Forest , eastern Assam , India with special reference to globally threatened and endemic species in the Eastern Himalayan biodiversity hotspot

Avifaunal survey of an Eastern Himalayan biodiversity hotspot area Jeypore Reserve Forest was carried out from July 2007 to July 2009. Altogether 270 species of avian fauna belonging to 56 families were identified during the survey, of which 58 species were frugivorous, 34 omnivorous, 15 carnivorous, 22 picivorous, five grainivorous and 136 were insectivorous in nature. Of all the bird species recorded, 14 were globally threatened species, five were endemic to this region, 153 were resident common species, 87 resident rare species, 16 migratory common species and 14 were migratory rare species. The endemic species recorded in the study area were Anorrhinus tickelli, Sphenocichla humei, Pellorneum palustre, Yuhina bakeri and Heterophasia pulchella. The globally threatened species include two Critically Endangered, Gyps indicus and Gyps bengalensis, one Endangered, Cairina scutulata, four Vulnerable, Leptoptilos javanicus, Francolinus gularis, Columba punicea, Turdoides longitostris, and seven Near Threatened, Anhinga melanogaster, Arborophila atrogularis, Anorrhinus tickelli, Buceros bicornis, Sphenocichla humei, Pellorneum palustre and Ichthyophaga ichthyaetus.

The Jeypore Reserve Forest is one among the few remaining tropical forest patches of eastern Assam which is a part of the Eastern Himalaya biodiversity hotspot region.This reserve is relatively undisturbed in terms of intrusions and disruptions by humans compared to other protected areas of the state.Jeypore along with five other protected areas form the Upper Dihing West Complex, an Important Bird Area (IBA) of eastern Assam, IBA Site No. IN-AS-45 (Islam & Rahmani 2004).Together they form the largest contiguous tropical rainforest area extent in the whole Brahmaputra Valley (Choudhury 1996).These sites are famous for the largest known population of the Endangered White-winged Duck Cairina scutulata (Choudhury 1996(Choudhury , 1998)).Apart from this, the area also harbours five species of hornbills including the rarer Brown Hornbill Anorrhinus tickelli and the Rufousnecked Hornbill Aceros nipalensis (Choudhury 2000).Due to its unique habitat and terrain, the site harbours a large diversity of avian fauna including endemic and globally threatened species.Past studies on avifauna of the reserve forest are restricted to a few personal comments and observations but detailed avifaunal surveys were not done specifically.Data on avian fauna of the reserve is deficient even though it is a part of an important IBA of eastern Assam which provides refuge to a large number of endemic and threatened species.Detailed ecological studies of the endemic and globally threatened species are required for their conservation.Therefore, the present study was conducted to provide up to date information about the avian diversity of the reserve forest and their habitat utilization patterns in order to provide baseline information for future conservation programmes.

Study Area
The Jeypore Reserve Forest (JRF) is located at Dibrugarh District of eastern Assam which falls between 27 0 06'-27 0 16'N and 95 0 21'-95 0 29'E (Fig. 1).The total area of the JRF is 108km 2 .The terrain of the area varies with slightly undulating plains to hills which are the foothills of the Patkai Range.The JRF is continuous with the forests of Arunachal Pradesh.Burhi-Dihing and the Dilli rivers form a part of the boundary of the reserve.Many small perennial streams and nullahs also flow within the forest.Swamps and grassland patches also occur inside the forest (Kakati 2004).This forest is a part of an important IBA-the Upper Dihing West Complex, IBA Site No. IN-AS-45 and was notified as a reserve forest way back in 1888 (Kakati 2004).The habitat is tropical rainforest, Champion & Seth (1968) described it as "Assam Valley tropical wet evergreen forest" (category 1B/C1) also called the upper Assam Dipterocarpus -Mesua forest.The forest is characterized by a top canopy dominated by Dipterocarpus macrocarpus reaching heights of 50m, a middle canopy dominated by Mesua ferrea and Vatica lanceaefolia and undergrowth consisting of woody shrubs such as Saprosma ternatum, Livistonia jenkinsiana and canes Calamus erectus, etc., (Kakati 2004).Bamboo species such as Dendrocalamus hamiltonii, Pseudostachyum polymorphum and climbers such as Derris oblonga are common.The major fauna of the reserve include large mammals such as Elephant Elephas maximus, Barking Deer Muntiacus muntjak, Bengal Tiger Panthera tigris, Leopard Panthera pardus, Clouded Leopard Neofelis nebulosa, Wild Boar Sus scrofa, etc. Primates such as Hoolock Gibbon Hoolock hoolock, Capped Langur Trachypithecus pileatus and Rhesus Macaque Macaca mulatta are also found in the reserve.Rock Python Python molurus and Banded Krait Bungarus fasciatus are some notable reptilian species.Besides these major faunas the reserve also harbours a large diversity of butterflies and arachnid species.Although the forest is located in a matrix of tea plantations, settled agriculture and rural settlements, the degree of disturbance is much less compared to other protected areas of the state.The peripheral areas of the forest are encroached by the local people for tea plantations but the core area of the forest is intact and without any disturbance.

Methods
Field surveys were conducted for a period of two years starting from July 2007 up to July 2009 covering all the seasons i.e.Summer (March-June), Monsoon (July-October) and Winter (November-February).The surveys followed line transect and point count methods (Bibby et al. 1992).Altogether 16 permanent line transects of 2km length and 50m breadth each were laid randomly, four transects each on all the major habitats of the forest closed canopy, grassland, open canopy and degraded areas near the forest edge.Also point counts were conducted along the line transects of each habitat on different days.Points were of 50m radius, at least 100m apart from each other to avoid overlap and counts were of 5min duration.In each habitat, 15 point count surveys were carried out.All the counts were carried out early morning, during the first three hours after sunrise as counts need to be carried out at the time of highest bird activity (Buckland et al. 1993).Opportunistic observations were also added to the list so as not to miss any species during the survey period.Feeding guilds were classified as per direct observations and available literatures Ali & Ripley (1987).Birds were identified using field guide books of Ali & Ripley (1987) and Grimmett et al. (2000).The common and scientific names of the birds given in the checklist followed the Birds of the World, recommended English names (Gill & Wright 2006).The threatened status of the birds given in the checklist is as per IUCN Red List of Threatened Species (Birdlife International 2001a,b).The common-rare, resident-migratory status of the birds are classified as per Saikia & Saikia (2000).
C -Common species which are encountered frequently (eight times during 10 survey trips).R -Rare species which are encountered less frequently (1-2 times during 10 survey trips).R -Residents, species found in the study area throughout the year.
WM -Winter Migrants, species found in the study area only during the winter.
SM -Summer Migrants, species visiting the area during the summer seasons.
Vr -Vagrants, species that are not regular, winter migrants or breeding migrants and hence a stray bird sighting.

Results
A total of 270 species of birds belonging to 56 families were identified during the survey (Table 1).Of these, 58 species were frugivorous, 34 omnivorous, 15 carnivorous, 22 piscivorous, five granivorous and 136 were insectivorous in their feeding guild.Out of 270 species of birds, 14 were globally threatened species and five endemic species including 30 migratory species, of which 25 were winter migrants, five summer migrants and one vagrant species.Family Timaliidae dominates the list with 35 species belonging to 20 genera followed by family Muscicapidae with 20 species under 14 genera and family Columbidae followed close by with 15 species belonging to six genera.Nine species out of these 270 are new records of the area belonging to the families, viz., Nectariniidae (3), Dicacidae (1), Sittidae (1), Muscicapidae (1), Pittidae (1), Psittacidae (1) and Charadridae (1).Out of the 270 species, 153 are resident common species, 87 are resident rare species, 16 are migratory common species and 14 are migratory rare species.Brown Hornbill Anorrhinus tickelli, Wedge-billed Wren-Babbler Sphenocichla humei, Marsh Babbler Pellorneum palustre, White-naped Yuhina Yuhina bakeri and Beautiful Sibia Heterophasia pulchella are the five endemic species.

Discussion
Eastern Assam falls under the endemic bird area of Eastern Himalaya which is one of the most important  biodiversity hotspot regions harbouring wide varieties of plants and animals inhabiting a diversified habitat mosaic (Stattersfield et al. 1998).The Jeypore Reserve Forest is one among the few remaining tropical forest patches of eastern Assam which is unique for its varied flora and fauna.The high diversity of frugivorous and insectivorous birds reveals the quality of the forest habitat.Apart from these, the study records 14 globally threatened species including two Critically Endangered species and five endemic species, which also adds to the uniqueness of this small forest patch.
The site should be given first priority for conservation of rare and endemic galliforme species such as Grey Peacock Pheasant Polyplectron bicalcaratum, Kaleej Pheasant Lophura leucomelanos, White-cheeked Partridge Arborophila atrogularis and Rufousthroated Partridge Arborophila rufogularis.Beside galliformes, the forest also harbours the endangered White-winged Duck Cairina scutulata.Out of the five species of hornbills found in JRF (Choudhury 2000), four species have been recorded from the site during present survey, except the Rufous-necked Hornbill Aceros nipalensis, which has not been encountered yet.
Since the reserve is continuous with the Patkai Range of Arunachal Pradesh, it provides a unique habitat not only for birds but also to many large and small carnivores, herbivores, primates and reptiles.The Insect diversity is also high including a large number of unknown arachnids for which detailed studies are required immediately.Thus the site is an ideal place for conservation of endemic and globally threatened birds and also to a large number of important flora and fauna.Due to the increase in human population the forest is presently facing disturbance in the edges which will increase in due course of time if proper conservation measures are not taken up immediately.Conservation awareness programmes among the local people is required to sensitise the people about the sustainable use of the forest resources to conserve it for future generations.

Figure 1 .
Figure 1.Map showing the study area of Jeypore Reserve Forest in eastern Assam.