Chan Yoke Meng’s images of the Horsfield’s Bronze Cuckoo (Chrysococcyx basalis) manipulating a caterpillar were photographed at Punggol Barat. This rare winter visitor flies in from Australia during the southern winter months of May to August.
Caterpillars are a favourite food for birds LINK.
However, there is a need to prepare the caterpillars before swallowing, especially those covered with hairs.
This involves rubbing it against a branch or moving it along its length when clamped between the mandibles to remove the stomach content LINK.
The Violet Cuckoo (Chrysococcyx xanthorhynchus) was observed swinging the caterpillar in the air to get rid of its gut content LINK.
This seems to be the same strategy used by the Horsfield’s Bronze Cuckoo as shown in the accompanying images. In the fourth and fifth images from the top, the greenish gut content is apparent in the posterior end of the caterpillar. Once the stomach content is got rid of, what remains of the caterpillar is swallowed.
The caterpillar does not come from a butterfly but probably from a moth. We consulted Khew Sin Khoon of Butterfly Circle who confirmed out suspicion. However, as our local moths have not been thoroughly studied, the identification of this particular caterpillar will have to wait…
Chan Yoke Meng & Khew Sin Khoon
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