People often refer to any unusually white animal as "albino," but albinism produces certain characteristics that some white animals don't have. Animals that are born white but don't exhibit albino characteristics have a different physiological expression that produces reduced pigmentation. In general, both albino and white animals are considered rare.
Characteristics of Albinos Versus White Animals
Aside from humans, albinism has been found among many life forms, from reptiles and amphibians, fish and shellfish, to sea mammals like whales and dolphins, and land mammals like mice, squirrels, bats, dogs, cats, deer, buffalo, and moose. Albino birds, insects and even plants are found in nature, as well.
Albinism is inherited. In most simple terms, it occurs when both male and female carry the recessive gene for the condition and, by a one-in-four chance, the offspring receives both recessive genes. With albinism, the body does not synthesize an enzyme needed to produce melanin, which is the chemical responsible for pigmentation. In addition to white fur, feathers or scales, an albino animal will have pink eyes and noticeably pink skin, especially around the ears, paws/feet, and nose/beak. The animal lacks pigment entirely.
The transparency of an albino’s eyes allows the color from the blood vessels behind them to show through, which creates the pink appearance. Therefore, a rule-of-thumb for easy classification is to check the eyes first to see if they are pink or dark. If the eyes are dark, then the animal is not albino, but has a condition called leucism. Leucistic animals produce pigment, but it is expressed only in certain regions of the body. These animals are either all white or have patches of white, but the most important distinction is that they have normal-colored eyes and skin.
Leucism has to do with variation in pigment cell activity. There may be several reasons why this variation is triggered, some of which are still being understood. It may be related to genetics, inbreeding, nutritional changes, or other causes. To explain further, hair follicles have proteins that are responsible for putting color into hair as cells grow and stack up. With leucism, for some reason the protein does not get activated at the shaft of the hair (or feather or scale) and the result is little or no coloring. Some animals born leucistic outgrow the condition as they mature.
Health Risks Shorten the Lifespan of Albinos
Unlike leucistic "white" animals, albino animals are at greater risk from illness and death because of their condition. Both albino and leucistic animals can be more conspicuous to predators in nature. Albino animals are in danger from being burned by the sunlight because of their delicate skin. This means albino snakes, alligators and frogs are threatened by the very sunlight they require to keep warm. Albino turtles have very poor eyesight, so have this added risk when trying to survive. Albino animals can develop skin tumors, cataracts, and other disorders that shorten their lifespan. Even when albinos or white animals survive illness and predators in the wild, they may be hunted by humans who wish to have a trophy.
Whether albino or white, people around the world revere the rare and intriguing event of getting to see an unusually colored animal. Read more about this in the article “Famous Albino and White Animals,” which examines notable albino and white animals around the globe.
Photo note: The house wren in the photo seen here has albino characteristics, except for the eye, which looks dark. Is the wren’s eye truly dark, or is it pink, but darkened by a trick of the light? When uncertain, it is acceptable among enthusiasts to use the term “partial albino” until there is more evidence to make a determination. This illustrates how the layperson uses the term “albino” more freely than does a scientist, who has the advantage of collecting and properly examining wildlife in order to make the correct distinction.
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