The moist sal forests, East Himalaya lower Bhabar sal and Eastern Terai sal forests, riverine successions, moist mixed deciduous forests and so many more include species like Tiger, leopard, clouded leopard, Golden cat, leopard cat, pangolin, Indian Elephant and Rhinoceros, Asian water buffalo, Gaur, Swamp deer and the Pygmy Hog.  

The area of Manas has roughly 45% grassland and 55% tree land as wildlife habitat. The river course may have about 100 sq.km. of reparian forests of grass and primary succession of tree cover, which is probably the most suitable water buffalo habitat any where and providing by far the best habitat for the tiger, where the concentration of the species is the highest. Inter 
and inter specific relation of the prey and predator in this area is extremely interesting and awaits scientific study to understand population dynamics and other evolutionary processes at work. In this area the ever changing river course cause erosion and accretion at the same time providing extraordinary dynamism to the habitat/ecosystems sustaining very high productivity. The 
rain fall in this area is very high about 450 to 500 cm and the temperature is also very conducive to add to the productivity.  

There are atleast two species of wild animals, endemic to this zone, Pygmy hogs and the Golden langur. The pygmy hogs are found, now only in this Tiger reserve, into known former range of distribution, while the Golden langur (Presbytis geei) have never been recorded beyond the limits of this Tiger reserve, though there are some late reports of this species occurring in some 
other areas besides the reserve, which needs verification. The status of pygmy hog had once dwindled to alarming levels and went out of sight for some time which led to the belief in the late fifties that the species had gone into total extinction. But the species was subsequently found by S.Deb Roy in the eastern part of the National Park during 1964. More animals were 
subsequently found surviving in another area, also included in the tiger reserve, but not in the core. This area has subsequently been declared as a sanctuary.  

The last available census figure of tigers is from 1988 when the figure was 92. Since then insurgency problems have prevented any tiger census but even though 4 tigers were poisoned in 1990 it is felt that the population is healthy.  

Political unrest and the resultant violence since early 1989 have taken the lives of 6 forest personnel. Anti-poaching, management, protection and all other activities are seriously effected as beat officers, rangers, anti-poaching camps, bridges etc have been attacked and burnt. The entire region is tense and the situation very fluid.  

The situation is not fool proof to contain the onslaught of smugglers and poachers. Determined and organised gangs of poachers equipped with sophisticated weapons and links with international smugglers sneak in to kill rhinos and elephants. There have been frequent encounters with such gangs resulting in casualties on both sides and the management has to remain ever vigilant. Funds are urgently required to restore and create communication links.  

Increasing human populations have exerted pressure on this rich habitat for its resources. The destruction of habitat and decimation of animal populations have resulted and degraded a large 'chunk of this ecosystem in the buffer area which is not under the control of the Field Director. The management is short of manpower, illequipped and suffers from paucity of funds to counter pressures in the buffer zone of this Park. However the core is intact and has not suffered from all the above. With all these constraints the field staff have managed and shouldered their responsibilities with courage, devotion and sacrifice.  

According to S.Deb Roy, Member Steering Committee of Project Tiger. "It is really painful to see the deliberate damage caused to the invaluable wildlife or natural heritage of the country and the world. Actually the true potential of this area and the natural wealth, it contains, may ever remain beyond the reckoning of man. Over twenty years of close association with the core 
area, where even most of the big trees also are known to me, has given me a clear lesson, that I took all these years to realise that I have probably just started to understand the ecology, after all! This is no humiliation, but stark reality about the complexity of the ecosystems and the innumerable interactions that are continuously taking place here. Irreparable damage to 
ecology in Manas may lengthen the list of human contempt about nature, which is adding to his blunders."