Great and Rhinoceros Hornbills: One year on

posted in: Courtship-Mating, Hornbills | 13


This account has now been published as:
Y. M. Chan, M. Chan and Y. C. Wee (2008).
Aberrant behaviour of a female Great Hornbill and a female Rhinoceros Hornbill.
Nature in Singapore. 1:31–34.
A PDF copy is available HERE.

Between February and May 2006, a pair of mixed Great (Buceros bicronis) and Rhinoceros Hornbills (Buceros rhinoceros), both female, was seen regularly at a patch of secondary growth at Eng Neo (1, 2). They were prospecting a tree cavity along the trunk of an old albezia tree (Paraserianthes falcataria).

The Great would regularly feed the Rhinoceros and lure the latter to the cavity. It would also check the cavity as if placing regurgitated food into it. This had the effect of getting the Rhinoceros flying over to also check the cavity.

It would appear that the Great was playing the role of a male while the Rhinoceros that of a female.

Although there was talk of one of the birds entering the cavity, most birders and photographers who were monitoring the hornbills have yet to see any image of this.

Recently the hornbills have been visiting the tree again. And as before, they regularly checked on the cavity.

Meng and Melinda Chan were around the area one day when they heard the honking of hornbills. Rushing to the tree, they noticed something inside the cavity. Soon a yellowish structure poked out – it was the casque of the Great Hornbill. The head followed and then the right side of the body.

Once the right wing emerged totally from the cavity, it unfolded completely with the head of the bird held high (above). Then the bird turned downwards while the left wing was still not completely out. Once both wings were free of the cavity, the bird dived down with the wings folded back before unfolding the wings fully and flying in a downward direction.

The Great Hornbill was in the cavity for a short while and emerged when she heard the Rhinoceros calling. When the pair was together, there was courtship feeding.

The good news is that the pair is still prospecting for a nesting cavity. It has gone one step further in that one of the birds actually entered the cavity. It is possible that one or the other had previously entered the cavity but not observed and documented.

The birds are regularly seen at the nearby Bukit Timah Nature Reserve. In January 2007 when a large fig tree was fruiting, both hornbills were regularly seen feeding there. Again, they regularly indulged in courtship feeding.

Now where do the birds end up at night? It was earlier reported that the Great spent most nights in a rain tree (Samanea saman) around a condominium along Adam Road. The Rhinoceros was never seen there. Obviously the two spent the night separately, meeting only during the day. What happened next is anybody’s guess…


13 Responses


    The Rhino plays the male role most of the time; although they interchange roles once in awhile. In this picture you see the locking of beaks.. the Great is inside. I can dig out my archive of this activities, if anyone is interested.

  2. Does their range include the Seletar area? I was at the Zoo a few weeks ago and was surprised to see what appeared to be a free-flying Great Hornbill perched in the Australian Outback exhibit.

  3. It appears that there is only one each of the Great and the Rhinoceros Hornbills in Singapore. So it you see either elsewhere, it has to be the same bird.

  4. That’s so cool! The Great Hornbill turned up on my balcony this evening, and perched on the railing. I heard she was quite friendly, pecked the glass a bit even before flying off. I wasn’t home then, but she gave my mum and sis a scare! My place is at Hindhede Walk, off Upper Bukit Timah and overlooking the Nature Reserve.

  5. Thanks Christine for your note. Keep a lookout for her roosting spot during the night. If she arrives around your place in the late evening, probably she will roost there.

  6. Update: the Great Hornbill just returned to my balcony for the 3rd time this evening. The 2nd time was somewhere last week, and at that 2nd time it brought the Rhinocerous Hornbill with it (to my mum’s shock!). Both times the Great Hornbill happily ate what fruits my mum put for it. This evening, it even squawked at my mother to move away before it came down to eat! I’m kind of in a hornbill-induced euphoria now, even though all these visits took place while I was at work, hence I must rely on my mum’s & sister’s accounts 🙂

    However, my mum said that the Great Hornbill that turned up the 2nd & 3rd time is a different one from the one she saw on 28 August (my post above). She said this one is noticeably smaller, thinner & shabbier than the one on 28 August. From the camera pics captured, I noticed the size difference too – one was huge, the other was somewhat smaller when compared to the balcony railing. But both were females and both had a ring around their foot. Coincidence? I don’t know, but hope someone here can shed light on why there seem to be 2 different female Greats around.

  7. As far as we know, there is only one Great and one Rhinoceros Hornbill around. Both are excapees. One or the other (or both) has a ring, with the organisation inscribed. Is it possible to send the images you have?

  8. If your observations were accurate, it could be two different specimens. These birds may still be kept as pets here and may have escaped. A clear pic will be good as the regular birders may be able to ID it better.

  9. Ok, I’ll try to get two pics uploaded. One is a video and is on my sister’s phone, and one is in my phone you see, so it’s a little difficult.

    Update: The Great came back yesterday, and this time it brought the Rhinocerous Hornbill again. According to my mum, they both came into the balcony to eat fruit. I got home soon after but missed them by 10 minutes 🙁

  10. […] the collapse of the old albezia tree (Paraserianthes falcataria) at Eng Neo, the pair of females, Great ( Buceros bicronis) and Rhinoceros Hornbills (Buceros rhinoceros), has moved to […]

  11. […] (Buceros rhinoceros) into the wild to provide a mate for the female Rhinoceros escapee that had inked up with a female Great Hornbill (B. […]

  12. […] (Buceros bicronis) (above left) and Rhinoceros Hornbill (Buceros rhinoceros) (above right) at Eng Neo during 2006-7 intrigued many Singaporean birders and provided subjects for many bird photographers. […]

  13. […] 23. Female hornbills’ aberrant behaviour LINK. […]


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