15/04/2023
LEUCISTIC ORANGE HEADED THRUSH :
all the melanin production in an animal's cells is affected by "albinism", which means such occurrence in partial manner isn't possible, therefore total transformation into white takes place…but the phenomenon where white colouration, white patches, spots or splotches appear on the skin is called "leucism"…
it was a summer afternoon we were exploring a forest of indian oak in nadia district of west bengal…we could hear the summer visitors, resident breeders, usual flycatchers and warblers from the branches of "hijol" and pink, purple flower bearing "jarul" - "pride of india"…a sultry day and we were tired walking through the vast forest land…the day was coming to an end and the light was getting bad when we suddenly spotted a white looking bird flew through the trees and landed on the bank of a water body…i could see the size of the bird while it flew past us but couldn't identify the species for its striking white colour…as the light was going down rapidly, it was getting difficult to spot the bird…very cautiously i tried getting closer to take at least one shot to identify the species…eventually i could see a couple of ground foraging bird - orange headed thrush, out of which one was this leucistic individual…i bumped up the ISO n dropped the shutter speed to somehow freeze a decent frame in the darkness but the jittery individual didn't allow me much time…
i could understand that it was a leucistic orange headed thrush in the field but nothing more than that…on returning when i opened my days collection on a laptop screen to take a closer look, i was thrilled to find out more about the individual…it not only has unusual pigmentation resulting in "leucism" but it also has overgrowth and deformities of beak which could be caused by AKD or "avian keratin disorder"…though AKD results in elongation and crossing of the mandibles of the beak but in this case the entire beak has grown bigger than normal and almost taken the shape of some other species of the same family…they say this kind of growth often appears deadly as it obstructs the bird's ability to feed and preen themselves, with the resulting dirty matted plumage unable to play its role in "thermoregulation", the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different…
orange headed thrush (zoothera citrina) - leucistic male…
sighted and photographed in nadia, west bengal, april 2023…
"these images is copyright protected, all rights reserved (c) 2019 with Bluebandwidth ...
...
Angshuman Ukil
