The sanctuary's minimal biotic interaction is a positive factor for its biodiversity. The forest department has created plantations of
sal and
teak in some parts. There are over 400 noted species of birds, including the endangered
rufous-necked hornbill and
white-cheeked partridge. At least 39 species of fishes have been documented in recent times. The sanctuary and its adjacent areas are ideal habitat for the endangered
Himalayan mahseer,
schistura sijuensis, clarias magur, and
Pillaia indica. The large mammals that live here include, the
Asian elephant,
tiger,
leopard,
clouded leopard,
leopard cat,
jungle cat,
fishing cat,
dhole,
Himalayan black bear,
sloth bear,
Hoolock gibbon,
slow loris,
capped langur,
rhesus macaque,
sambar deer,
muntjac,
gaur,
binturong, and
black giant squirrel.
Wild boar,
civets, and
mongoose, are also found in the sanctuary. Four species of hornbills are found in the area, rufous-necked hornbill,
great hornbill,
Malabar pied hornbill, and
wreathed hornbill. In addition, there are various species of woodpeckers, bulbuls, laughingthrushes, and minivets, including winter visitors from higher biomes. In 2021 researchers found the
Disk-footed bat for the first time in the Lailad area near the sanctuary. This was almost 1000 km from the nearest known habitat in
Myanmar. It is one of at least 66 species of
bats found in the state. A new species of bamboo-dwelling bat, found near the sanctuary, was classified as
Glischropus meghalayanus in 2022. It was the first reported dwelling of the thick-thumbed bat in South Asia. In 2024 researchers from
Ashoka Trust for Research in Ecology and the Environment found the dung beetle species
Onitis bordati in the sanctuary for the first time expanding its known range from
Vietnam and
Thailand. == Management ==