Tan Teo Seng observed a pair of adult Oriental Pied Hornbills (Anthracoceros albirostris) busily hopping from branch to branch of a leucaena (Leucaena leucocephala) tree, also known in Malay as petai belalang. The hornbills were pecking at the ripened pods of the tree, trying to get at the seeds. This resulted in bunches of fruits falling to the ground below (left).

They then flew off to a nearby horse-radish (Moringa pterygosperma) or drumstick tree and also tackled the ripened pods, apparently to get at the seeds. Again, many of the disturbed pods landed on the ground (below).

The ripened seeds of both these legumes are hard and this leaves one to wonder whether the hornbills were actually eating the seeds.

Teo Seng did not see the hornbills actually throwing the seeds from the bill tip directly into the throat. Thus in the absence of such a behaviour, was the hornbills actually eating the seeds? Teo Seng will be keeping a close lookout for such behaviour the next time.

The observations were made in late May 2010 in a fruit farm in Kota Tinggi, Johor, Malaysia. It was raining heavily then and the adult hornbills were foraging in the rain. The juvenile that was with them did not join in but remained under the shelter of the house.

Images by YC Wee.

“Visits by the Oriental Pied Hornbill (Anthracoceros albirostris convexus) to our urban Ipoh garden have been one of the most unexpected and delightful events in our lives. Although there are many in Perak (Peninsular Malaysia), they are largely confined to lowland rain forest, swampy location, near rivers and some islands.

“We have seen them twice before in our garden – eight and three years ago, once a single individual, the second time a pair. Both prior were in June-August months (dry season).

“Today [13th June 2009, 6pm], just when arriving back from work, was delighted to hear a female calling out loudly, making some of my neighbor’s curious as to the sound. I got the camera and rushed out without changing. It was hard to spot her in the foliage of a tall tree and as I got close she flew into the overgrown nearby graveyard. I followed (despite being “inappropriately” dressed) and saw a House Crow (Corvus splendens) chasing her off from another tree. Fortunately I had recoded her calls (with the Nikon D90) and played them back. After some time of doing so, spotted her on a tall bare branch some distance away, calling again and got some good views for 30 minutes.

“A composite above shows the posture during calls. The head would be arched back, the beak open and a loud “crackling bray/laugh” - HERE.

More rarely she made a softer, closed bill, piping sound HERE.

“She spent close to 30 minutes calling – with breaks of 2-4 minutes in between and calls durations of 10-30 seconds.

“I was at first considering the A. a. albirostris subspecies because the undersurface of the tail looked back in flight but on processing the shots, recognised I had been fooled by the tail opening in flight to reveal the upper tail feathers. So it is A. a. convexus sbspecies. A composite to show this.”

Dato’ Dr Amar-Singh HSS
Canning Garden Home
Ipoh, Perak, Malaysia
20th February 2010

“It was early morning on Labour Day (1st May 2010). An Oriental Pied Hornbill (Anthracoceros albirostris) was observed to be harvesting fruits from one of the many MacArthur Palm trees (Ptychosperma macarthurii), which were fruiting in the area.

“It selected only the ripened red-coloured fruits; using the tip of its beak to pick them up. The selected fruits were then flicked expertly into its oral cavity - always one at a time (above). When it had its fill, it flew to a nearby tree and began to preen itself. After some preening, it suddenly flipped its head to one side to an angle of about ninety degrees. In just an instance, its head resumed to its normal position. Its mandibles were seen opening narrowly and then closing. Its head was then tilted up slightly with its beak partially opened. A slight movement of its head forward resulted in one seed emerging from out of nowhere to appear briefly at the tip of its beak (below). The seed that was regurgitated was then allowed to drop into the bushes below.

“Subsequently, this hornbill continued to feed on the MacArthur Palm for another two rounds, preening itself in different trees in between. There was no other regurgitation seen.

“What happened next was totally unexpected. The hornbill somehow lost its balance and had to perform some acrobatics to salvage itself from the indignity of being upside-down (above). It found itself in an upside-down position when it suddenly plunged forward with its head and long neck going well below the level of its perch. Its strong grip on the perch prevented it from falling off the branch. It managed to balance itself by half-spreading its wings. Somehow, it gathered sufficient strength to lift itself awkwardly back to its normal upright perching posture.

“Birds do not normally lose their balance on their perches. This is the first time that I have caught sight of a bird losing its balance while it was perching.”

Kwong Wai Chong
Singapore
10th May 2010

Raju Kasambe of Nagpur, India managed to photograph the bill grappling and aerial jousting of the Indian Grey Hornbill (Ocyceros birostris) in Nagpur, India. Raju has been studying this hornbill for the last three years but only on 20th March 2010 was he successful in obtaining good images.

The two hornbills indulged in such behaviour while perching on the same branch or on two nearby branches of a tree. They even bill-grapple when airborne, before landing on the branch of a tree. One male was seen tearing a short piece of branch from a tree it was perching on when confronting a nearby male.

Such behaviour has been described by Kemp (2001) as having “no obvious or immediate function.” It also includes mandibulating of sticks in the bill.

An earlier post describes the Malabar Pied Hornbills (Anthracoceros coronatus) indulging in locking bills between two males in northern Karnataka, India. Such play took place during flight to pre-roosting trees. Between different sexes, only gentle touching of bills was observed.

Over in Johor, Malaysia, interlocking of bills was reported in the Oriental Pied Hornbill (Anthracoceros albirostris).

Reference:
Kemp, A. C., 2001. Family Bucerotidae (Hornbills). In: del Hoyo, J., A. Elliott & J. Sargatal (eds.). Handbook of the birds of the world. Vol. 6. Mousebirds to Hornbills. Lynx Editions, Barcelona. Pp. 436-523.

Image by Raju Kasambe.

Kennie Pan photographed a male Oriental Pied Hornbill (Anthracoceros albirostris) feeding his mate when both were perching on a branch of a tree (above). The male had a fig held at the sharp tip of his huge bill. He was offering it to his mate who responded by delicately taking over the fig with the tip of her bill.

This is courtship feeding, as seen in may species of birds… bee-eaters, barbets and koel. The two hornbills have apparently bonded and were then in courtship mode. At the same time the pair was allopreening – the male using the sharp tip of his bill to preen the female. In the image on the left, her neck is stretched backwards to expose the surface to the attention of the male.

The female on the right has a smaller casque. Note that has her right eye is closed, no doubt enjoying the preening. The casque of the male, seen to the left of the female, is larger.

No doubt copulation would follow and the pair would be prospecting for a tree cavity, if not already done so.