Home Archive Reader Photos Being monochrome in a coloured world

Being monochrome in a coloured world

By AG STAFF • 19 September 2014

The 'white' magpie (Cracticus tibicen) most likely has a defect know as leucism, which causes the lack of pigmentation at cell level. He would have been born this way, as opposed to gradually losing his coloured markings. Image credit: Wayne Day

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A lone magpie with a rare pigment condition shines white in the crowd

This week’s reader photo was taken by Wayne in Evans Head, New South Wales.

“It was something a little uncommon – a white magpie! I was lucky to have spotted it while driving through Evans Head,” says Wayne.

The magpie (Cracticus tibicen) photographed by Wayne most likely has a genetic defect known as leucism.

Leucism is a general term caused by defects in pigment cells during development. The hiccup in the genes result in either the entire surface (if all pigment cells fail to develop) or patches of body surface (if only a subset are defective) having a lack of cells capable of making pigment.

This defect differs from that of albinism, as the animal retains areas of normal colouring, such as the beak, legs and eyes. Leucism can also result in the ‘piebald’ effect sometimes seen in horses and pythons, where the lack of pigmentation only occurs in some areas.

Another contrast between albinism and leucism is in eye colour. Due to the lack of melanin production in both the retinal pigmented epithelium and iris, albino animals typically have red eyes. This is due to the underlying blood vessels showing through, while in contrast, most leucistic animals have normally coloured eyes.