Biodiversity – Status of Environment related issues: Assam ENVIS Centre, Ministry of Environment and Forests, Govt. of India

| Last Updated:: 12/12/2023

Animal Diversity

Photo Source: Internet

ANIMAL DIVERSITY

Assam is part of the transitional zone between the Indian, Indo- Malayan and Indo-Chinese Biographical regions which provides the gateway for spread of both oriental and Palaearctic fauna to other parts of the country. Favourable climate, topographic and edaphic factors support luxuriant growth of diverse plant communities and create varied habitats. The forest as well as extensive network of river systems and swamps, marshes and wetlands provides ideal conditions and suitable habitat for sustenance of wide variety of fauna with existence of one of the most diverse faunal population mammals, primates, reptiles, amphibians, fishes, molluscs, birds, butterflies, moths etc.

Fauna	No. of Species
Mammals	193
Primates	9 (Out of 15 Indian primate species 9 are found in Assam)
Birds	950 (State is home to 53.5% of the bird species found in the Indian Sub- Continent, 17 species of birds are endemic to Assam) 45 species of birds from Assam find mention in the Indian Red Data Book.
Migratory birds	280
Amphibians	Assam and other parts of the N.E. region have 70 species of Amphibions reported from the region which 60+ species are found in Assam. Gangenophis fulleri and Ichthyphis garoensis are endemic to Assam.
Butterflies	Around 1500 species of butterflies are reported from India of which nearly half are reported from Assam and N.E. India.
Moths	About 387 species of moths are reported in the state.
Reptiles	116 (19 species of tortoises and 77 species of snakes and lizards are found in the state)
Molluscan	39 species of freshwater snails have been reported from Assam of which 10 species are used as food.
Fish	185 (25 species are identified as Threatened)
Mosquito	156

(Source: Environment and Forest Department, Assam)

Mammalian diversity: Assam forms the western most boundaries for the Indo-Chinese species including primates and the easternmost limit of several peninsular mammalian fauna. The distributional extent of several Indian has terminated in Assam plains. The distributional range of several Indo-Chinese fauna gets its sustenance from this region. Assam is home to all the primate species found in the region. Assam’s mammalian diversity is represented by 193 species which are widely distributed in this region. But of late some of the species have their distribution limited to isolated pockets and protected areas. For example: Great Indian One-Horned Rhinoceros, Tiger, Bears, Squirrel, Wild Asiatic Water Buffalo, Eastern Swamp Deer, Elephants, Gaur, Sambar, Indian Muntjac, Wild Boar, Hog Deer, Jungle Cat, Leopard Cat, Hispid Hare (rare), Indian Gray Mongoose, Small Indian Mongooses, Large Indian Civet, Small Indian Civets, Bengal Fox, Golden Jackal, Sloth Bear, Indian Pangolins, Chinese Pangolin, Hog Badger, Chinese Ferret Badgers, Parti-coloured Flying Squirrel, Gangetic Dolphin, Wild Pig, Pigmy Hog, Barking Deer, Himalayan Black Bear, Porcupine, Burmese Ferret Badger, Sloth Bear, Wild Dog (Dhole), Leopard, Clouded Leopard, Binturong, Golden Cat, Himalayan Palm Civet, Common Palm Civet, Fishing Cat, Feral Horses, Marbled cat, Golden cat, Spotted linsang, Binturong, Crab eating mongoose, Ferret badger, Hog badger, Hoary bamboo rat, Bay bamboo rat, Clawless otter, Stone marlin.

Primate diversity: Out of 15 Indian primate species 9 are found in Assam. Hoolock gibbon is the only ape found in India. The other primate species are golden langur, capped monkey, rhesus macaque, pigtail macaque, stump tailed macaque, Assamese macaque, and slow Lorries. Golden langur or “Sonali Bandar” as it is known locally is confined between Sankosh river in the west; Manas in the east; Brhmaputra in the south and mountains in Bhutan in the north. Pigtail macaque and stumped tailed macaque locally known as Gahorinejia Bandar and “Senduiria Bandar” respectively are distributed in the Eastern, central and southern part of the state. Rhesus macaque, capped monkey and Assamese macaque are more or less distributed through the State. Assamese macaque and Rhesus monkeys are also found in villages and in urban areas.
Most of the primates are predominately arborcal in nature but Rhesus monkey, Assamese macaque and stump tailed macaque are partly terrestrial also.
Slow Lorries is the only prosimian found in Assam and the N.E. region. For example: Assamese Macaque, Rhesus macaque, Stump tailed macaque, Capped langur, Golden langur, Hoolock macaque, Slow Loris etc.

Avian Diversity: Assam is one of the “endemic bird areas” in the world. With 950 bird species the State is home to 53.5% of the bird species found in the Indian Sub- Continent, 17 species of birds are endemic to Assam and include Manipur Bush Quail, Marsh Babbler, Snowy throated Babbler, Tawny breasted Wren Babbler, Blyth’s Tragopan, Beautiful Sibia, Grey sibia, Black breasted Parrotbill, Chestrunt breasted partridge, Rusty breasted shortwig etc. 45 species of birds from Assam find mention in the Indian Red Data Book and include white winged wood duck, Blyth’s Tragopan, Greater Adjutant, lesser Adjutant, Leser white fronted Goose, Merbled Teal, Beer’s Pochard, Palla’s Sea Eagle, Greater spotted Eagle, Green Peafowl, White rumped vulture, longbilled vulture etc. For example: Black breasted parrot bill, Jerdons babbler, Marsh babbler, Pale capped pigeon, Crested serpent eagle, Giffon vulture, Grey headed fishing eagle, Crested serpent eagle, Spot billed pelican, Baers pochard, Lagre cormorant, Open bill stork, Large whistling teal, Grey leg goose, Black necked stork, Greater crested grebe, Lesser adjutant stork, Grater adjutant stork, Great spoted eagle, White ramped vulture, Longo billed vulture, Black bellied term, Rufous necked hornbill, Wreathed hornbill, Great pied hornbill, White necked stork, Brahminy duck, Pintail duck, White winged wood duck, Pallas fish eagle, Lesser adjutant stork, Baza, Bengal florican, Hornbill, Osprey (endangered), Ferruginous duck, Common pochard, Red crested pochard, Shoveller, Gargany, Wigeon. Gadwall, mallard, Spot billed duck, Grey leg goose, Bar headed goose, Indian vulture, Slender-billed vulture, Indian white-rumped vulture, Lesser white-fronted goose, Ferruginous duck, Baer's pochard duck, lesser adjutant, greater adjutant, black-necked stork, and Asian openbill stork migrate from Central Asia to the park during winter, Riverine birds (Blyth's kingfisher, White-bellied heron, Dalmatian pelican, Spot-billed pelican, Nordmann's greenshank, Black-bellied tern), Eastern imperial (Rare), Greater spotted, White-tailed, Pallas's fish eagle, Grey-headed fish eagle, lesser kestrel, Game birds (Swamp francolin, Bengal florican, Pale-capped pigeon) great Indian hornbill, wreathed hornbill, Old World babblers (Jerdon’s and marsh babblers), weaver birds (common baya weaver, threatened Finn's weavers), Thrushes (Hodgson's bushchat), Old World warblers (bristled grassbird), Black-breasted parrotbill, Rufous-vented prinia (Threatened), Swamp patridge, peafowl, Hill myna, Spot billed pelican, White pelican,

Reptilian Diversity: Assam’s varied physiography and habitant conditions support a rich variety of reptilian population. Gangetic gharial, 19 species of tortoises and 77 species of snakes and lizards are found in the State. For example: Reticulated Python, Indian Rock Python, Myanmarese Python, Black Krait, Common Blind Snake, Pit Viper, King cobra, Indian Cobra, Monocled Cobra, Monitor Lizard (Bengal monitor and the water monitor), Russell's viper, Common krait, Assam Roofed Turtle (Endemic), Indian Soft Shell Turtle, Indian Flap Shell Turtle, Keeled Box Turtle, South East Asian Leaf Turtle, Brown Tortoise.

Amphibian Diversity: Assam and other parts of the N.E. region have 70 species of Amphibions reported. Gangenophis fulleri and Ichthyphis garoensis are endemic to Assam.

Fish Diversity: The Brahmaputra and Barak river system along with their tributaries and flood plain wetlands locally known as beels provide very conducive habitant for an array of fish species, Assam and other parts of N.E. region is recognized as one of the hot spots of fresh water fish biodiversity. 197 food, sports and ornamental fish species are reported from the region of which 185 are reported from Assam. The important ornamental fish species are colisa, Nemacheilus, Danio, Botia and Chaca. Commercially important fish species include, Rohu, Ktla, Pabha, Pabda Chital, Magur, Singi, Sol, etc. Over exploitation is posing serious threats to fish diversity and 25 species are identified as threatened.

Molluscan Diversity: The river systems and extensive flood plains also harbour fresh water molluscs. So far 39 species of freshwater snails have been reported from Assam of which 10 species are used as food.

Butterfly and Moths Diversity: These most beautiful creatures on earth with around 1500 species of butterflies are reported from India of which nearly half are reported from Assam and N.E. India. The Swallowtail butterflies occupy an important place and the IUCN has identified the entire N.E. Region as Swallowtail rich zone. Butterflies play an important role in pollination of plants and besides being important aesthetically they play important role in biodiversity conservation. About 387 species of moths are reported and most of the moth’s species are distributed throughout the State

Population of Rhino, Elephant, Tiger, Leopard and any others primates in various censuses in the State:

Name of Animals	Year of Census	Number of Animals
Elephant	2002	5246
	2008	5281
	2009	5620
Tiger	1997	457
	2000	354
	2009	143
Rhino	2006	2006
	2009	2201
	2011	2503
Leopard	1993	239
Leopard	2000	248
Any others-Primate	2009	127502
(i) Rhesus Macaque	2009	72674
(ii) Assamese Macaque	2009	30866
(iii) Slow Loris	2009	431
(iv) Pig Tailed Macaque	2009	649
(v) Capped Langur	2009	17813
(vi) Golden Langur	2009	2772
(vii) Hoolock Gibbon	2009	1517
(viii) Stumptailed Macaque	2009	648
(ix) Phayre's leaf Monkey/Spectacled Langur	2009	132