I had an extended opportunity to watch an immature male Asian Emerald Cuckoo (Chrysococcyx maculatus) feeding. This small cuckoo was feeding on caterpillars (above) high in the canopy of a Delonix regia (Flame of the Forest).
Caterpillars were branch swiped before being consumed and the bird frequently cleaned the bill after feeding (above).
It consumed a large number of these small caterpillars, in excess of 30 feeding episodes observed in 3 hours. At times the bird would sit immobile for an extended period. At times there was Little Bronze-Cuckoo (Chrysococcyx minutillus peninsularis) feeding on the caterpillars in the same tree, but there was no competitive feeding behaviour.
The common feeding method was to search for and identify a prey (often on the leaves) from a perch, then launch out and pluck the prey off the leaves, and return to a new perch (composite above).
Very much like the aerial sally of a flycatcher, possibly due to the smaller size of this cuckoo. Occasionally it would lean over (above) or stretch up to reach a prey (below).
I had one very unexpected observation, that I am almost reluctant to mention, but was also seen/confirmed by a bird watching colleague. We saw a large butterfly ‘buzz’ the Asian Emerald Cuckoo and chase it away. I have seen this with other birds often, but whether a butterfly has the sentience to chase away a predator feeding on its (presumed) offspring is uncertain.
Postscript:
“Your last paragraph interests me. Male Monarch butterflies Danaus plexippus of North America are known to ‘chase away’ birds and other insects that stray into their territory. There are Danaus sp. here in Malaysia too. Any photos of the butterfly?”
Amar-Singh HSS (Dato’ Dr)
Ipoh, Perak, Malaysia
Location: Perak, Malaysia
Habitat: Secondary growth adjacent to limestone outcroppings
Date: 15th December 2020
Equipment: Nikon D500 SLR with Nikon AF-S Nikkor 500mm f/5.6E PF ED VR, handheld with Rode VideoMic Pro Plus Shotgun Microphone