Strange behaviour of Asian Glossy Starling

posted in: Feeding chicks | 5

On 23rd April 2007 I received a couple of interesting images from Heng Fook Hai (left). At the Changi boardwalk he noticed an Asian Glossy Starling (Aplonis panayensis) flying into the hollow top portion of a palm post and emerging with what looked like a fig in its bill. Fook Hai was intrigued, and so was I.

The hollow tops of these posts are favourite nesting sites of Dollarbirds (Eurystomus orientalis). The starling was taking out fruits rather than bringing them into the hollow portion. So it was obviously raiding someone’s larder, possibly the Dollarbird’s. And Dollarbird does indulge in courtship feeding. But does the male Dollarbird places fruits inside potential nesting cavities to persuade the female to enter it and lay her eggs? Birders have yet to report on this behaviour.

However, the Oriental Pied Hornbill (Anthracoceros albirostris) does this regularly (1, 2, 3). The pair of female Great (Buceros bicronis ) and Rhinoceros (Buceros rhinoceros) Hornbills playing house at Eng Neo similarly indulge in the same thing. And regularly, Hill Mynas (Gracula religiosa) and Javan Mynas (Acridotheres javanicus) raid the tree cavity of food.

Subsequent images sent in by Meng and Melinda Chan helped solve the mystery. They noticed starlings flying above to swiftly dive into openings at the tops of palm posts with food in their beak. After a few minutes these birds emerged with what must be seeds for disposal. The images on the left show a bird dropping the seed into the sea below.

The birds were obviously nesting at the top of the semi-rotting posts sunk into the seabed. They were feeding their young, bringing in fruits with large seeds. It is possible that the young swallow the fruits to regurgitate the seeds and the adult then remove them. Adult starlings regularly swallow palm fruits and regurgitate the seeds.

YC Wee (text), Heng Fook Hai (images: top two) & Meng and Melinda Chan (images: bottom two)

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5 Responses

  1. The mystery deepens!

    Were ther ‘figs’ eaten or dropped into the sea!

    Were those ‘palm seeds’ truly palm seeds or the ‘figs’!

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  2. Nobody tried to retrieve the discarded “seeds” from the sea. From the images we have, they look like seeds alright, maybe not plam seeds. Too smooth to be figs.

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  3. Could they be fecal pellets?

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  4. They look more like seeds to me – too smooth and shiny to be faecal pellets.

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  5. Good post. You make some great points that most people do not fully understand.

    “The hollow tops of these posts are favourite nesting sites of Dollarbirds (Eurystomus orientalis). The starling was taking out fruits rather than bringing them into the hollow portion. So it was obviously raiding someone’s larder, possibly the Dollarbird’s. And Dollarbird does indulge in courtship feeding. But does the male Dollarbird places fruits inside potential nesting cavities to persuade the female to enter it and lay her eggs? Birders have yet to report on this behaviour.”

    I like how you explained that. Very helpful. Thanks.

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