“A sizable proportion of the Great Egrets (Ardea alba modesta) were in some degree of breeding plumage. The composite in the image below shows the beak and loral skin changes moving from non-breeding to breeding (upwards).
“1. Beak from yellow-orange with the tip black to fully black.
“2. Loral skin from olive-yellow to cobalt blue.
“3. Legs from black to pink.
“The image above compares a bird in good breeding plumage (in flight) with pink legs with a bird in non-breeding plumage with black legs (below).
“The image below shows a bird with pink legs with near complete loral skin and beak changes but minimal breeding plumes.
“There is however much variation and different ‘styles’ of development of breeding plumage; meaning that there does to seem to be a fixed direction in which plumage or bare parts changes happen. I saw birds with well developed breeding plumes with limited bare part colour changes or breeding plumes that pre-dated bare part changes.
“The above shows is of a bird with well-developed breeding plumes but only just developing a black beak and limited loral skin changes.”
Dato’ Dr Amar-Singh HSS
Ipoh, Perak, Malaysia
27th March 2017
Location: Kota Kinabalu, Sabah, Borneo, Malaysia
Habitat: Coastal region
A recent paper in the Science journal covers the topic of animal colouration.
Thanks Kang Min.