Nagi Bird Sanctuary is located in Jhajha Jamui district of south Bihar, near the Jharkhand border.

The highly revered Jain pilgrimage site of Lachhuar and temple city of Deoghar are 50 and 80 km away from the sanctuary respectively.

The sanctuary is surrounded by undulating peninsular landscape with tor formations on barren land interspersed by rocky outcrops.

As a result of the construction of Nagi Dam, a sufficient quantity of water gets impounded in the reservoirs during rainy season which is later utilized for irrigation through a canal network running downstream.

[5] The arrival of migratory birds begins in October with the coming of white wagtails and black redstarts.

The sanctuary teems with waterbirds until February, after which the migrants start flying back to their home range in Central Asia, the Arctic Circle, the Russian taiga and northern China.

Migratory birds observed in the sanctuary are Eurasian marsh harrier, greater short-toed lark, mallard, common tern, western yellow wagtail, olive-backed pipit, Richard's pipit, blue rock thrush, common snipe, Blyth's reed warbler, falcated duck, Kentish plover, steppe eagle, Eurasian wigeon, common pochard, greylag goose, tufted duck, northern pintail, ferruginous duck, gadwall, bar-headed goose, red-crested pochard, northern shoveler, ruddy shelduck, black-necked stork, Jacobin cuckoo, common kestrel, barn swallow, brown shrike, brown-headed gull, citrine wagtail, white wagtail, black redstart, red-breasted flycatcher, osprey, great crested grebe, Eurasian coot, little ringed plover, common sandpiper, little stint, Temminck's stint, common greenshank, wood sandpiper and the green sandpiper.

The reason for the arrival of a large number of migratory birds is the extent of the wetland and the thriving of aquatic plants, plankton and molluscs in the reservoir.

The paddy fields around the sanctuary provide a rich habitat for insects and dragonflies which are preyed upon by many resident birds.

Resident birds of the sanctuary are Indian robin, ashy-crowned sparrow-lark, Asian koel, Asian pied starling, bank myna, baya weaver, black-bellied tern, black drongo, black-headed ibis, black-hooded oriole, black kite, black-winged kite, brahminy starling, bronze-winged jacana, Indian silverbill, Indian roller, cattle egret, brown-headed barbet, house crow, large-billed crow, common hawk cuckoo, common hoopoe, common kingfisher, common myna, white-throated kingfisher, common tailorbird, coppersmith barbet, Eurasian collared dove, spotted dove, rufous treepie, jungle babbler, Asian green bee-eater, gray francolin, Indian grey hornbill, house sparrow, Indian chat, Indian courser, Indian pond heron, cotton pygmy goose, large cuckooshrike, laughing dove, lesser whistling duck, little cormorant, Indian shag, Oriental darter, Oriental magpie robin, red-naped ibis, painted stork, plain prinia, pied kingfisher, purple sunbird, purple heron, grey heron, red-vented bulbul, little grebe, red-wattled lapwing, yellow-wattled lapwing, river tern, rose-ringed parakeet, scaly-breasted munia, shikra, spotted owlet, white-breasted waterhen, Indian thick-knee, yellow-footed green pigeon and the woolly-necked stork.

There are over 30 species of fish in the sanctuary like rohu, catla, chanari (ambassisnama) and bulla or tank goby (Glossogobius giuris).

Agricultural runoff, open defecation, biomass extraction, grazing and illegal fishing are the main threats facing the sanctuary.