How to differentiate Male & Female Crested Serpent Eagle? Sarawak, Malaysian Borneo (1 Viewer)

[dixonlau]

Location: Sibu, Sarawak, Malaysian Borneo

These photos were taken last November 2021. Based on the photos, I was wondering if can differentiate which is Male/Female or one could be still juvenile?

Left bird can clearly see many white spots on its underparts. Also the white spots appeared much bigger compare to Right bird. Could this feature pointed Left bird as Mature Male?

No idea for the Right bird.






This is Left bird before the another fly in and landed on the Right side (Right bird).



Thanks.

 

[Earnest lad]

I dont know if the field guide helps but it doesnt mention any differences between male and female. Only juveniles

 

[ratt]

I don't know if there is a slight difference, but both birds in the pictures look subtly different to India ones I saw at rest. And I can't really explain what i mean. I know this doesn't help in any way. Maybe something with the head, or just the 'pose' they have. Interesting for me though.

 

[RafaelMatias]

In raptors females are typically larger (within a pair), even when plumage wise both sexes look approximately the same (as is the case here). The bird on the left is larger, though perhaps not too obviously. Look at the legs: the tarsi are considerably thicker and more robust (despite the slightly different angle) on the bird on the left and the "trousers" are also visibly larger. The bird on the left is the female, in my opinion.

 

[Grahame Walbridge]

In raptors females are typically larger (within a pair), even when plumage wise both sexes look approximately the same (as is the case here). The bird on the left is larger, though perhaps not too obviously. Look at the legs: the tarsi are considerably thicker and more robust (despite the slightly different angle) on the bird on the left and the "trousers" are also visibly larger. The bird on the left is the female, in my opinion.

Agreed Raphael and note also, the birds are not yet fully mature as evidenced by the white-scaled scapulars, adults have more uniform upper parts.

Grahame

 

[RafaelMatias]

Agreed Raphael and note also, the birds are not yet fully mature as evidenced by the white-scaled scapulars, adults have more uniform upper parts.

Grahame

Cheers Grahame and Happy New Year.

 

[dixonlau]

Thank you guys for all the help. I do agreed with Rafael the Left bird is larger.

Just sharing one of the video footage I managed to capture of the Left bird when it is alone and being attacked by another smaller bird. Perhaps the live footage may help in confirming it is Female indeed.

Thanks and have a pleasant New Year!