Rufous-necked hornbill 
(Niệc cổ hung, Aceros nipalensis) 

The rufous-necked hornbill (Aceros nipalensis) is a species of hornbill in Bhutan, northeastern India, especially in Arunachal Pradesh, Indian Subcontinent and Southeast Asia.

Compare:
- Rufous-necked hornbill: Both have tripes on the uppder mandible of the beak, tripes are flat on the upper mandible and no casque; rufous-necked for males and black neck for female; blue color around the eyess.
- Wreathed hornbill: the stripes are raised on the upper mandible to form a casque; black for both genders, possess a sac or pouch on the throat which has a blueish band across.

Bucerotiformes, Bucerotidae, Buceros: Latin bucerus horned like an ox (Greek boukeros: horned like an ox: bous ox; keros: horn).
Aceros: Greek akeros: hornless.