WHAT MAKES ANIMALS WHITE
- In albinos, the cells are unable to produce the pigment melanin, which gives the skin or fur its normal colour. Pure albinos usually have pink eyes, nails, scales and skin because the pink of their blood vessels shows through.
- In some animals, the eyes of an albino appear light blue or green because of the way light passes through the iris. In partial albinos, only some of their body appears white, while the rest has the typical colours of the species.
- Leucistic animals are, just like albino ones, unable to produce melanin. However, some of the cells responsible for creating pigment can still function. Like the white giraffes, this leads to white or light-coloured individuals which have some other pigments - such as dark eyes and nails.
- Other genetic conditions cause animals to be white. For instance, the phenomenon called kermodism affects black bears living in British Columbia, Canada, turning them white. This is due to a mutation of the same gene associated with red hair and fair skin in humans. Scientists from the University of Victoria found that salmon the bears feed on tend to react less to white shapes above water than black ones, which gives the white bears a slight advantage when hunting the fish.
- A related condition is piebaldism, where patches of cells are unable to produce melanin, leading to white shapes and patterns on the surface of the animal. This is common in many animals, including dogs, cats and horses.
- Some animals turn white for the winter. It is unclear why this is so, but apart from camouflage in the snow, some researchers believe a pale coat may have better insulating properties and keep the animal warmer.
- These various conditions are easily confused with one another.
- Pigments are very important to animals. They provide camouflage, protect the skin and eyes from the sun, and are used to attract mates. Animals that are completely white because of albinism or leucism are extremely rare in the wild, since the lack of camouflage colours makes them easy targets for predators. The lack of pigmentation in the eyes can also cause vision problems for albino animals, leading to problems when looking for food, avoiding predators, or searching for mates.
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