Thong Chow Ngian made an interesting point-by-point morphological comparison of juvenile and mature Crested Serpent eagles (Spilornis cheela). Below is his photographic records of the species and the description of their differences.
Juvenile Crested Serpent Eagle at Goldhill Avenue
On 22 Jun 2021, I went to Goldhill Avenue to look for the juvenile Crested Serpent eagle (Spilornis cheela). It flew in at about 9.30am and perched on a tall tree, see Photo 1. Its appearance was new to me which I find fascinating. I have seen the adult eagles several times before, especially in West Malaysia, Borneo and also Pulau Ubin and the juvenile’s physical appearance took me by surprise.
Physical differences between the juvenile and adult eagle
I would like to make a physical comparison between the juvenile eagle and the adult eagle in 3 ways: the front view, the side view and also the crest.
Mobbing and aggression behaviours
I also observed that the juvenile eagle was constantly harassed by crows and 3 Oriental Pied Hornbills. They seem to be taking turns carrying out mock attacks.
But when the juvenile eagle returned back to perch on the tree, the hornbills took turns to create a ruckus by yelling at the eagle and carried out mock attacks.
However, the young eagle was no push over and held its ground.
It was indeed an interesting encounter with the juvenile Crested Serpent eagle.