28 March 2015. Grey Herons, Ardea cinerea, at Jurong Lake. Two nests with chicks. Parent flapping its wings and squawking away very loudly. A Changeable Hawk-Eagle, Nisaetus cirrhatus, perched on top of nest was eyeing its chicks. A Large-billed Crow, Corvus macrorhynhos, kept watch on the next branch.
Second crow flew in to harass the Changeable Hawk-Eagle.
The Changeable Hawk-Eagle stayed on its perch and tried to fend the crows off.
But eventually gave up and flew away. This looked like one species defending another but……
The Crows then flew back and settled on one side of the tree after chasing away the Hawk-eagle. I did not stay long enough to see what happen next. I can only assume that the crows were waiting to strike once the parents leave the nest unguarded.
This is the prize that both were going after. The younger chick can just be seen behind the older chick. The Herons were not agitated with the crows perched nearby. It is because they are smaller than the Hawk-eagle? If any one of you come across any attacks by the crows on the Heron’s nestings, please drop us a line.
Singapore Bird Group 