Wild Great Hornbills (Buceros bicornis) Do Not Use Mud to Seal Nest Cavities

The literature pertaining to nesting of the Great Hornbill (Buceros bicornis) is ambiguous regarding whether the birds use mud as plaster material to seal their nest cavity entrances. We studied the breeding biology of the species in southern India and detected no evidence of mud delivery or usage in 183 hrs of nest observations. Chemical analysis of plaster material showed that it was composed exclusively of fecal material and not mud.