Lesser Coucal – adult non-breeding or juvenile

posted in: Morphology-Develop. | 0
Bird 1.

“I saw these two Lesser Coucals (Centropus bengalensis javanensis) together, which is unusual as they are often solitary. I am trying to decide if they are adults in non-breeding plumage or juveniles (or one of each or subadults) as they can be very similar. Cuckoos of the World, by Johannes Erritzøe, Clive F. Mann, Frederik P. Brammer and Richard A. Fuller. Helm, 2012 states and illustrates some of the differences (see table below):

Bird 1.

“The images at the top and above are the same bird (Bird 1) and the two images below is another accompanying bird (Bird 2).

Bird 2.

“I am of the opinion that Bird 1 is a juvenile moulting into an adult non-breeding plumage. See especially the tail that has mixed features of a juvenile and adult.

“Bird 2 had a much shorter tail and was in moult (especially tail) with some black on the breast. This appeared to me to be an adult in moult and transforming into non-breeding plumage.

Bird 2.

“This I think explains why they were together – a late stage juvenile with the supportive adult.

“Appreciate opinions (more images, view possible).

“I have sent this to Clive F. Mann for an opinion.”

Dato’ Dr Amar-Singh HSS
Ipoh, Perak, Malaysia
3rd December 2019

Location: Perak, Malaysia
Habitat: Wetlands, Padi Fields

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