Leucism in crows
Posted by BESG on 27 May 09, Wednesday
Contributed by Daisy O'Neill
A pair of House Crows (Corvus splendens) was observed in a residential area perched on a television antenna. One was black and the other was a light brown colour- and that was something odd (below left).
Let’s listen in.
“Ma, why am I so different?”
“Did I fall into a bucket of bleach?” asked the juvenile crow in sepia.
“No…, you did not and I don’t know why you were born like this, dear. And that makes you even more special!” replied the black House Crow as she proceeded to preen her chick tenderly.
Feather shafts of birds sink into the skin organ to receive the necessary nourishment for growth and endowment of birds’ plumages. Colours of feathers are determined by the genetic make up and quantity distribution of pigmentation cells present in the skin.
Leucism in birds is a genetic disorder whereby the pigmentation cells are unevenly distributed, hence resulting in patches of feathers looking paler, bleached looking or show white. (While Albinism dictates that the skin body is totally devoid of pigmentation cell. Hence, if one looks into the iris of an albino, it always shows reddish-pink or near equivalent.)
The image (above right) shows an adult leucistic House Crow. Note especially the uneven discolouration of the beak, white naped patch and wings and dark eyes to compare with a flock of normal House Crows (below left).
It was also observed that the leucistic House Crow was treated as an out-caste and chased off by other crows while the former was scavenging and ate lunch (above right).
It is not a common phenomenon and science has yet to figure out why leucism occurs. Perhaps… it is one of those things that Mother Nature, the divine architect sees fit – to be allowed to mastermind mistakes now and then!
And which ascertain that in our world, nothing and nobody is perfect… and we be allowed to do so sometimes too.
Three sightings of leucistic House Crows were made in 2008 at the same location.
AVIAN WRITER DAISY O’NEILL PENANG MALAYSIA
© LEUCISM IN CROWS
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Categories: Crows, Morphology-Develop., Writer-Avian
Comment by Charlie Moores
Made Wednesday, 27 of May , 2009 at 4:58 pm
Hi YC, Daisy
I posted about leucism with some interesting photos on the 10,000 Birds blog at http://10000birds.com/mystery-bird-on-kauai-hawaii.htm - I’ve linked here but I was wondering if I could get permission to add your photo of the House Crow to our post? I’ll of course add all links/credits etc.
Thanks
Charlie
Pingback by Leucistic ‘Mystery Bird’ on Kauai, Hawaii
Made Wednesday, 27 of May , 2009 at 6:12 pm
[...] an interesting example of a leucistic House Crow have a look at a post on the excellent Bird Ecology Study Group [...]
Comment by YC
Made Wednesday, 27 of May , 2009 at 6:29 pm
Have contacted Daisy for her permission.
Pingback by Bird Ecology Study Group » Tale of an albino crow
Made Tuesday, 2 of June , 2009 at 9:15 am
[...] up on Daisy O’Neill’s post, attached are photos taken in 1973 of another unusually-coloured crow that used to reside with me. [...]
