Manas Tiger Reserve is biologically very rich. It is located in the confluence of 3 major Bio-geographic Zones viz. Lower Gangetic plains (7B), Central Himalayas (2C), and Brahmaputra valley (8A). The project site supports a vital population of the tiger (Panthera tigris). Significance of Manas Tiger Reserve in the International context lies in the fact that it provides shelter and protection to various species of Wildlife included in the Red Data Book (RDB) of the IUCN (International Union for Conservation of Nature and Natural Resources) and the appendices of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora).

 The core area of MTR being a World Heritage Site has been providing the universal conservation value towards nature and human being.  

Besides, Royal Manas National Park of Bhutan is situated in the northern boundary of MTR. This is an international corridor for migration wildlife between Manas National Park and Royal Manas National Park in Bhutan.

List of (Critically Endangered, Endangered, Near Threatened and Vulnerable) fauna of Manas Tiger Reserve as per IUCN Red Data list and the Wildlife (Protection), Act, 1972

Sl. No. Common Name Zoological Name IUCN category WLP (Schedule)
1 Pygmy Hog Porcula salvanius Critically Endangered I
2 White-bellied Heron Ardea insignis Critically Endangered I
3 Slender-billed Vulture Gyps tenuirostris Critically Endangered I
4 White-rumped Vulture Gyps bengalensis Critically Endangered I
5 Bengal Florican Houbaropsis bengalensis Critically Endangered I
6 King Vulture Sarcogyps calvus Critically Endangered IV
7 Orchid Tit butterfly Chliaria othona Data deficient I
8 Golden Langur Trachypithecus geei Endangered I
9 Tiger Panthera tigris Endangered I
10 Fishing Cat Prionailurus viverrinus Endangered I
11 Asian Elephant Elephas maximus Endangered I
12 Indian Water Buffalo Bubalus arnee Endangered I
13 Hispid Hare Caprolagus hispidus Endangered I
14 Chinese Pangolin Manis pentadactyla Endangered I
15 White-winged Wood Duck Cairina scutulata Endangered I
16 Narrow-headed Softshell Turtle Chitra indica Endangered I
17 Assam Roof Turtle Pangshura sylhetensis Endangered I
18 Indian Wild Dog/ Dhole Cuon alpinus Endangered II
19 Hog deer Axis porcinus Endangered III
20 Yellow Tortoise Indotestudo elongata Endangered IV
21 Short-nosed Vine Snake Ahaetulla nasuta Endangered IV
22 Greater Adjutant Stork Leptoptilos dubius Endangered
23 Leopard/Panther Panthera pardus Near Threatened I
24 Asiatic Golden Cat Pardofelis temminckii Near Threatened I
25 Great pied Hornbill Buceros bicornis Near Threatened I
26 Large Indian Civet Viverra zibetha Near Threatened II
27 Malayan Giant Squirrel Ratufa bicolor Near Threatened II
28 Striped Keelback Amphiesma stolata Near Threatened II
29 Banded Krait Bungarus fasciatus Near Threatened II
30 King Cobra Ophiophagus hannah Near Threatened II
31 Spot-billed Pelican Pelecanus philippensis Near Threatened IV
32 Oriental Darter Anhinga melanogaster Near Threatened IV
33 Painted Stork Mycteria leucocephala Near Threatened IV
34 Black-necked Stork Ephippiorhynchus asiaticus Near Threatened IV
35 Black-headed Ibis Threskiornis melanocephalus Near Threatened IV
36 Ferruginous Duck Aythya nyroca Near Threatened IV
37 Grey-headed Fish Eagle Ichthyophaga ichthyaetus Near Threatened IV
38 Lesser Grey-headed Fish Eagle Ichthyophaga humilis Near Threatened IV
39 Cinereous Vulture Aegypius monachus Near Threatened IV
40 Pallid Harrier Circus macrourus Near Threatened IV
41 Laggar Falcon Falco jugger Near Threatened IV
42 Black-bellied Tern Sterna acuticauda Near Threatened IV
43 Blyth’s Kingfisher Alcedo hercules Near Threatened IV
44 Rufous-vented Prinia Prinia burnesii Near Threatened IV
45 Rufous-rumped Grassbird Graminicola bengalensis Near Threatened IV
46 Brahminy Blind Snake Ramphotyphlops braminus Near Threatened IV
47 Burmese Rock Python Python molurus bivittatus Near Threatened IV
48 Common Water Snake Enhydris enhydris Near Threatened IV
49 Common Wolf Snake Lycodon aulicus Near Threatened IV
50 Green Cat Snake Boiga cyanea Near Threatened IV
51 Checkered keelback Water Snake Xenochropis piscator Near Threatened IV
52 Indian Rat Sanke Ptyas mucosa Near Threatened IV
53 Ornate Flying Snake Chrysopelea ornata Near Threatened IV
54 Common Otter Lutra lutra Near Threatened
55 Himalayan Keelback Rhabdophis himalayanus Near Threatened
56 White-lipped Pit Viper Cryptelytrops albolabris Near Threatened
57 Brown roofed turtle Pangshura smithii Near Threatened
58 Chital Fish Chitala chitala Near Threatened
59 Capped Langur Trachypithecus pileatus Vulnerable I
60 Clouded Leopard Neofelis nebulosa Vulnerable I
61 Marbled Cat Pardofelis marmorata Vulnerable I
62 Sloth Bear Melursus ursinus Vulnerable I
63 Great Indian Rhinoceros Rhinoceros unicornis Vulnerable I
64 Gaur/ Indian Bison Bos gaurus Vulnerable I
65 Swamp deer Rucervus duvaucelii Vulnerable I
66 Rufous-necked Hornbill Aceros nipalensis Vulnerable I
67 Malayan Box Turtle Cuora amboinensis Vulnerable I
68 Spotted Pond turtle Geoclemys hamiltonii Vulnerable I
69 Water Monitor Lizard Varanus salvator Vulnerable I
70 Yellow Monitor Lizard Varanus flavescens Vulnerable I
71 Bear Cat or Binturong Arctictis binturong Vulnerable I
72 Himalayan Black Bear Ursus thibetanus Vulnerable II
73 Smooth Indian Otter Lutrogale perspicillata Vulnerable II
74 Sambar Rusa unicolor Vulnerable III
75 Eastern  Imperial Eagle Aquila heliaca Vulnerable IV
76 Greater Spotted Eagle Aquila clanga Vulnerable IV
77 Pallas’ Fish Eagle Haliaeetus leucoryphus Vulnerable IV
78 Lesser Kestrel Falco naumanni Vulnerable IV
79 Swamp Francolin Francolinus gularis Vulnerable IV
80 Manipur Bush Quail Perdicula manipurensis Vulnerable IV
81 Wood Snipe Gallinago nemoricola Vulnerable IV
82 Dark-rumped Swift Apus acuticauda Vulnerable IV
83 Marsh Spotted Babbler Pellorneum palustre Vulnerable IV
84 Jerdon’s Babbler Chrysomma altirostre Vulnerable IV
85 Black-breasted Parrotbill Paradoxornis flavirostris Vulnerable IV
86 Slender-billed Babbler Turdoides longirostris Vulnerable IV
87 Bristled Grass Warbler Chaetornis striata Vulnerable IV
88 Hodgson’s Bushchat Saxicola insignis Vulnerable IV
89 Finn’s Weaver Ploceus megarhynchus Vulnerable IV
90 Yellow-breasted Bunting Emberiza aureola Vulnerable IV
91 Red-neked Keelback Rhabdophis subminiatus Vulnerable IV
92 Common Mock Viper Psammodynastes pulverulentus Vulnerable IV
93 Lesser Adjutant Stork Leptoptilos javanicus Vulnerable  
94 Peacock Softshell Turtle Nilssonia hurum Vulnerable  
95 Tricarinate Turtle Melanochelys tricarinata Vulnerable  
96 Bengal Monitor Lizard Varanus bengalensis Vulnerable
97 Assam Snail Eater Pareas monticolus Vulnerable

The Manas National Park harbors at least 61 species of mammals, 450 species of birds, 42 species of reptiles, 9 species of amphibians, 79 species of fishes and more than 200 species of butterfly and over 100 species of invertebrates.

 Manas National Park supports at least six critically endangered, fifteen endangered, thirty-six near threatened and thirty-nine vulnerable fauna as per the IUCN Red Data List.

Besides this, 32 species are also listed in Schedule-1 of Wildlife (Protection) Act, 1972. Pygmy Hog (Porcula salvania) is exclusively endemic to the Manas National Park and also included in the critically endangered status of the IUCN Red Data Book.

About 622 species plants have been recorded in the Manas (Hajra & Baisya, 2002). Of these 30 species are pteridophytes, 162 species are monocots and 429 species are dicots and one species gymnosperm. No detailed studies have been made regarding the algal and fungal species of Manas. Medicinal plants also have been recorded from the Park. The list of 462 plants are enclosed (Annexure-I) and rest 160 are in the process of identification up to species level. 

 The four species of endemic plants have been recorded from the Manas so far are: Boesenbergia hamiltonii (formerly Curcomorpha longiflora), Echinocarpus assamicus, and Paspalum longifolium var lorirhachis.