Oriental Pied Hornbill locking bills

“Pasir Ris Park is possibly the best place to observe Oriental Pied Hornbills (Anthracoceros albirostris) in Singapore now. At least 15 birds were counted at 2 different corners of Pasir Ris Park in mid June 2016.

“On 21 August, I found at least 7 of these magnificent hornbills foraging on top of a fruiting Angsana tree (Pterocarpus indicus). They flew off above the canopy of the Angsana tree before I could approach nearer (below).

“Chasing after them led me to some tall slender trees where a few hornbills have perched and were probing deep into the foliage. Observed that they were plucking and eating fruits on these trees. A male holding a fruit harvested from the tree is attached (below).

“Found out later that these trees are known as Mast Trees (Polyalthia longifolia) (below).

“Turning my attention to 2 females in an adjacent tree (below), …

“…I was instantly rewarded when one of the birds leaped over to engage the other and bills were locked for a brief second (below).

“Female “A” that had leapt across and was in mid-air returned back to where it was before.

“Seconds later, it took another leap and bills were again locked.

“From one of the photos, Female “B” had its bill wide opened with the head of Female “A”, which was in mid-air, appearing to be within its wide opened gape.

“However, Female “A” was not flustered and it landed below Female “B”.

“Both birds were engaged for the next 10 seconds locking bills in various poses.

I must stress that the locking of bills by these females did not appear to be fights as there seemed to be no aggression at all.

“I would think that this locking of bills is a form of social interaction as I have even encountered juvenile siblings similarly locking bills.

“This would suggest that the siblings were in social behaviour.

“Would appreciate any opinions.”

Kwong Wai Chong
Singapore
31st August 2016