Manas Sanctuary
COUNTRY-INDIA(ASSAM)
IUCN MANAGEMENT CATEGORY IV (Managed Nature Reserve)
X (World Heritage Site; Criteria ii, iii, iv)
BIOGEOGRAPHICAL PROVINCE 4.09.01 (Burma Monsoon Forest)
GEOGRAPHICAL LOCATION The sanctuary lies in the districts of Barpeta and Kokrajhar, 41km north of Barpeta Road township. It spans the Manas River and is bounded to the north by the international border with Bhutan, to the south by the populated regions of North Kamrup and to the east and west by forest reserves. The sanctuary, which includes part of Manas Reserve Forest and all of North Kamrup Reserve Forest, constitutes the core of Manas Tiger Reserve which lies in the forest divisions of Kachugaon, Haltugaon, Western Assam Wildlife and North Kamrup. 26°37'-26°50'N, 90°45'-91°15'E
DATE AND HISTORY OF ESTABLISHMENT Manas (previously also known as North Kamrup) was declared a sanctuary on 1 October 1928, parts of it having been notified as reserved forests in 1907 and 1927. It was established as the core of the Manas Tiger Reserve with effect from April 1973. Designated a World Heritage site in December 1985. Upgrading of the sanctuary to national park status is being considered.
AREA The sanctuary comprises 39,100ha of the 283,712ha Manas Tiger Reserve. In 1971, 809ha from the sanctuary was allocated for a seed farm. Manas Sanctuary is contiguous with Royal Manas National Park (65,800ha) in Bhutan.
LAND TENURE State
ALTITUDE Ranges from 40m to 150m.
PHYSICAL FEATURES Lying in the foothills of the Outer Himalaya, the area is low-lying and flat. The Manas River flows through the western portion of the sanctuary, where it splits into three separate rivers, and joins the Brahmaputra some 64km further south. These and other rivers running through the tiger reserve carry an enormous amount of silt and rock debris from the foothills, resulting from the heavy rainfall, fragile nature of the rock and steep gradients of the catchments. This leads to the formation of alluvial terraces, comprising deep layers of deposited rock and detritus overlain with sand and soil of varying depth, shifting river channels and swamps. The northern portion is represented by the 'Bhabar' formation, which is very porous due to the deep deposits of coarse detritus overlain by sandy loam and then a thin layer of humus. The 'Terai' tract in the south consists of fine alluvial deposits with underlying pans. Here, the water table lies very near to the surface. The area of the Boki basin, in the west of the sanctuary, is sometimes inundated during the monsoon but never for very long due to the sloping relief. Mortality to wildlife is negligible as animals are able to stake refuge on islands of high ground.
CLIMATE The climate is warm and humid (up to 76% relative humidity) with most rain falling during the monsoon season (May-September). The mean maximum summer temperature is 37°C and the mean minimum winter temperature is 11°C. Mean annual rainfall ranges from 3332mm at Batabari to 4489mm at Kachugaon, based on 11 and 17 years of records, respectively (Anon., 1974; Deb Roy, n.d.).
VEGETATION The three main types of vegetation are:-
(a) Tropical semi-evergreen forests in the northern part of sanctuary, with common trees including Aphanamixis polystachya, Anthocephalus chinensis, Syzygium cumini, S. formosum, S. oblatum, Bauhinia purpurea, Mallotusphilippensis, Cinnamomum tamala, Actinodaphne obvata;
(b) tropical moist and dry deciduous forests (the most common type), characterised by trees such as Bombax ceiba, Sterculia villosa, Dillenia indica, D. pentagyna, Careya arborea, Lagerstroemia parviflora, L. speciosa, Terminalia bellirica, T. chebula, Trewia polycrapa, Gmelina arborea, Oroxylum indicum, Bridelia spp.; and
(c) extensive alluvial grasslands in the western part of the sanctuary, comprising many different grass species together with a variety of tree and shrub species (e.g. Dillenia pentagyna, Phyllanthus emblica, Bombax ceiba, and species of Clerodendrum, Leea, Grewia, Premna and Mussaenda). The grasslands can be subdivided into wet alluvial and highland savanna types. There is also a considerable variety of aquatic flora along river banks and in the numerous pools (Jain and Sastry, 1983). Dry deciduous forests represent early stages in succession and are replaced by moist deciduous forests away from water courses, which, in turn, are succeeded by tropical semi-evergreen climax forest. Grasslands cover about 50% of the sanctuary. Some 393 species of dicotyledons, including 197 trees, and 98 species of monocotyledons have been identified (Jain and Hajra, 1975; S. Deb. Roy, pers. comm.).
FAUNA A total of 55 mammals, 36 reptiles and 3 amphibians has been recorded (Project Tiger, n.d.). Manas harbours by far the greatest number (21) of India's Schedule I mammals of any protected area in the country. Many are typical of South-east Asian rain forest and have their westernmost distribution here. Mammals include golden langur Presbytis geei (R), a recently discovered endemic restricted to Manas and adjoining areas in Bhutan and numbering approximately 305 in 1980, capped langur P. pileata, Hoolock gibbon Hylobates hoolock, clouded leopard Neofelis nebulosa (V), tiger Panthera tigris (E), second largest population in India with 123 recorded in 1984, leopard P. pardus (V), golden cat Felis temmincki (I), fishing cat F. viverrinus, leopard cat F. bengalensis, marbled cat F. marmorata (I), binturong Arctictis binturong, sloth bear Melursus ursinus (I), wild dog Cuon alpinus (V), Ganges dolphin Platanista gangetica, Indian elephant Elephas maximus (E), with up to 2,000 in the tiger reserve and more than 1,000 moving freely between Indian and Bhutan Manas reserves, Indian rhinoceros Rhinoceros unicornis (E), with about 75 individuals in 1980, pygmy hog Sus salvanius (E), swamp deer C. duvauceli (V), sambar Cervus unicolor, hog deer C. porcinus, Indian muntjac Muntiacus muntjak, water buffalo Bubalus arnee (V), probably representing the only pure strain of this species in India, gaur Bos gaurus (V), giant squirrel Ratufa indica, hispid hare Caprolagus hispidus (E) and Indian pangolin Manis crassicaudata.
Over 300 species of birds have been recorded including the threatened Bengal florican Houbaropsis bengalensis (E), great pied hornbill Buceros bicornis, wreathed hornbill Rhyticeros undulatus and other hornbills. The Bengal florican population was estimated at 34 for the whole tiger reserve in 1984 (Ali et al., 1985) and 24 male territories were identified within the wildlife sanctuary during 1988 (Narayan et al., 1989). Pied harrier Circus melanoleucos nested during 1988 and 1989, the first confirmed record for India (Narayan et al., 1989). Uncommon waterfowl species include spot-billed pelican Pelecanus philippinensis, lesser adjutant stork Leptoptilos javanicus and greater adjutant stork L. dubius.
Reptiles include a variety of snakes (e.g. vine snake Ahaetulla nasutas, flying snake Chrysopelea ornata, Assam trinket snake Elaphe frenata and banded krait Bangarus fasciatus), gharial Gavialis gangeticus (E) (possibly introduced from neighbouring Bhutan or as a result of a captive breeding programme), and monitor lizard Varanus sp. Assam roofed turtle Kachuga sylhetensis (K) has recently been recorded (Sarma, 1988).
CULTURAL HERITAGE Manas takes its name after the Goddess Manasa. The surrounding area is inhabited predominantly by tribal people (Deb Roy, n.d.).
LOCAL HUMAN POPULATION There is one forest village in the south-east of the sanctuary, which it is proposed to dereserve and enlist as a revenue village along with other contiguous revenue villages (Deb Roy, n.d.). Some 54,000 people are distributed among 144 villages in the buffer zone of the tiger reserve (Anon., 1974); no relocation of these villages is contemplated (Deb Roy, n.d.).