Tuesday, March 24, 2015

Yellow-tailed Black Cockatoo



Australia has five species of black Cockatoo's and these black Cockatoo's are endemic to Australia and found nowhere else in the world. I was so delighted to spot one of these blacks, that despite it not being a good image, I anyway decided to post it on the blog.
The bird is the Yellow-tailed Black Cockatoo (Calyptorhynchus funereus ) once called by John Gould as the Funeral Cockatoo. Four of these five black Cockatoo's are listed as threatened. The population of Yellow-tailed too is declining and may be a matter of time before it joins the other four. Loss of habitat and illegal pet trade are the primary reasons for their decline.
Now for some interesting- Although Cockatoo's are related to the parrots, they are never found in green or blue colour, like the parrots. Colours in birds are produced not just by pigments, but by microscopically structured surface on the feathers. When light reflects of these surface from various layers, it causes interference. The greens and the blues are caused by something called constructive interference and the structure responsible for it is called the Dyck texture. Cockatoo's lack this structure in their feathers hence the lack of greens and blues in them.

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