Thursday, December 22, 2011

The Awesome Imperfection of a Piebald Grackle

We can’t all be perfect. I dare say that no one is and the same can be said for the greater animal kingdom. Most people know what a Black Bear looks like. But not all Black Bears are black. Genetic mutations occur to the benefit or detriment of the species and express themselves in such ways such as color variations. The Kermode Bear, an all-white subspecies of the Black Bear is found in British Columbia. The Cinnamon Bear, a red-brown furred subspecies is found in the Rockies. Thousands of years ago mutations in their genes gave rise to populations of these subspecies that are now unique and self-sustaining.

This brings me to the oddity hopping in a crosswalk in Immokalee, Florida. From its shape, size and tail feathers I knew what it was immediately, but the colors it was displaying looked as if someone had left an ink pen in the wash with a pair of white underwear. Male Boat-tailed Grackles normally have dazzling, iridescent blue-black plumage, but this one looked more like a seagull mated with a crow in a tornado.

This is known as a “piebald” morph and can be expressed in mammals, birds and reptiles. This grackle has a random assortment of skin and feathers that lacks melanin. This is not to be confused with albinism which is the complete lack of melanin or leucism which is a reduced amount of all pigments. It is possible that this bird could mate and pass on the piebald gene but the offspring will not retain the same pattern. The odds of finding a mate are not good though. Male Boat-tailed Grackles (Quiscalas major) have courtship duels to impress the females and without the sexy iridescence, the piebald grackle probably doesn’t stand a chance. Excessive whiteness can also cause issues with thermal retention.

Take it for what you will, this grackle was dropping what I assumed was food from a wire into the street and retrieving smaller bits after cars had run it over. I know ravens and crows do this. It was fun to see this grackle do it as well. 

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