Oriental Pied Hornbill locking bills

posted in: Hornbills, Intraspecific | 1

“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.

OPH [KwongWaiChong] 1

“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).

OPH [KwongWaiChong] 2

“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).

OPH [KwongWaiChong] 3

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

OPH [KwongWaiChong]  4

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

OPH [KwongWaiChong] 5

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

OPH [KwongWaiChong] 6

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

OPH [KwongWaiChong] 7

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

OPH [KwongWaiChong] 8

“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.

OPH [KwongWaiChong] 9

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

OPH [KwongWaiChong] 10

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

OPH [KwongWaiChong] 11

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.

OPH [KwongWaiChong] 12

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

OPH [KwongWaiChong] 13

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

OPH [KwongWaiChong] 14

“Would appreciate any opinions.”

Kwong Wai Chong
31st August 2016

  1. Amar-Singh HSS

    Have seen this before. if you are sure there is no aggression then consider ‘bill-twinning’. A form of avian social interaction either as comfort or consolation.
    See discussion in “Bird Brain: An Exploration of Avian Intelligence by Nathan Emery”.

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