White-breasted Waterhen – juvenile to adult

posted in: birds, Morphology-Develop. | 0

I saw a self feeding immature White-breasted Waterhen (Amaurornis phoenicurus phoenicurus) and decided to look at many images I had taken over time to display changes with age. There are problems with this ‘display’ due to posture, lighting, clarity of images, but I have chosen from many images to try and get what I think is a possible ‘evolution’. The composite in post 1 shows 6 birds in various life-stages (above).

1 is a very young juvenile (chick) with all black plumage except for a small white ear patch and pale vent (in some). The bill and feet are all black.

2 is an older juvenile with white in the neck and breast, rufous-orange at vent and under-tail coverts. The lower mandible is getting lighter and legs are orange-brown.

3 is the oldest juvenile stage where the birds are still with parents. The plumage is more like adults but the upperparts are often brownish with a rufous-orange at vent and under-tail coverts. The lower mandible is lighter and legs are orange-brown.

4 is a self feeding immature bird. The upper parts are grey-black and the neck-breast white is still ‘dirty’ with residual grey-black areas. The bill is ivory and legs a dirty bronze (see Post 2 for a full image of this bird seen 28th December 2020)

5 is a subadult with some residual grey in plumage and less well developed bill colours than the adult.

6 is an adult. The bill is yellow-green with a darker upper mandible with red at the base, and legs are yellow-orange.

I have to consider if the birds in stage 3, of which I have seen and imaged a few, are in some ways different from those in stage 4 i.e. some colour aberration? I do not think so. The only way to be sure would be to follow up the same chick up to adulthood. These past 2-3 months we have seen a White-breasted Waterhen take up residency in our wild urban garden. If it breeds then we may have a first hand opportunity to watch juveniles change into adulthood.

The image above shows a self feeding immature bird and that below a self feeding immature bird.


Amar-Singh HSS (Dato’ Dr) – Ipoh, Perak, Malaysia

Location: Ipoh, Perak, Malaysia

Habitat: Open fields limestone hills

Date: 28th 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


Follow YC Wee:

Dr Wee played a significant role as a green advocate in Singapore through his extensive involvement in various organizations and committees: as Secretary and Chairman for the Malayan Nature Society (Singapore Branch), and with the Nature Society (Singapore) as founding President (1978-1995). He has also served in the Nature Reserve Board (1987-1989), Nature Reserves Committee (1990-1996), National Council on the Environment/Singapore Environment Council (1992-1996), Work-Group on Nature Conservation (1992) and Inter-Varsity Council on the Environment (1995-1997). He is Patron of the Singapore Gardening Society and was appointed Honorary Museum Associate of the Lee Kong Chian Natural History Museum (LKCNHM) in 2012. In 2005, Dr Wee started the Bird Ecology Study Group. With more than 6,000 entries, the website has become a valuable resource consulted by students, birdwatchers and researchers locally and internationally. The views and opinions expressed in this article are his own, and do not represent those of LKCNHM, the National University of Singapore or its affiliated institutions.

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