Leucism vs. Albinism in the Animal Kingdom

Leucism and albinism are often difficult to tell apart in animals since the conditions share some of the same characteristics. While albinism refers to the complete lack of melanin—the natural pigment that gives skin, feathers, hair, and eyes their color—leucism involves a partial loss of pigmentation.

Animals with albinism are white or pale in color over their entire bodies but also have eyes that are pale, pink, or red in color, while animals with leucism often have partially white or patchy features with darker eyes.

What Is Albinism?

Albinism in animals occurs when an individual member of a species inherits a mutated gene from both parents that interfere with their body’s ability to produce melanin. The most obvious trait among those with albinism is pale white skin, hair, plumage, fur, or scales. The same mutation that affects the skin also affects the blood vessel pigments in the eyes, making them appear red or pinkish in color rather than white.

These inherited genetic traits are all recessive and must be inherited from both parents (who don’t necessarily have to have albinism themselves).

With all the obstacles that animals must overcome to survive in the wild, those with albinism have it much worse. Their loss of pigmentation makes it difficult to camouflage to avoid predators or hunt for food and often gives them reduced vision.

The condition also increases their exposure to harmful ultraviolet light and can make it more difficult to find a mate. Animals have even been observed excluding members of their group with albinism to avoid predation of the entire population.

Unfortunately, their rarity also puts them in amplified danger to poachers, as well, who can sell them in the illegal wildlife trade to collectors or as exotic pets.

For this reason, albino animals that are discovered in the wild are sometimes captured and brought to zoos or sanctuaries for their own protection. In 2018, for instance, a conservation group in Indonesia built a special 12-acre reserve for a critically endangered, orphaned albino orangutan named Alba that they rescued from a cage in a local village. 

What Is Leucism?

Animals that are white in color are often mistaken for having albinism when they actually have leucism. Leucism results in a reduction in all types of pigments, not just melanin, so an animal with leucism may either have pale or muted colors or irregular patches of white.

Like albinism, leucism is inherited, though the severity and positioning of the muted colors can vary between parents and offspring or even skip generations in the case of recessive genes. Some leucistic animals, like this all-white moose photographed in Sweden, have very few differences from those with albinism.

Often, the simplest way to tell animals with leucism apart from albinism is to look at the eyes. Animals with leucism will have dark-colored eyes rather than red or pink.

A bird with leucism, for example, may be completely white or patchy but still have melanin in its system, as the genetic mutation only applies to melanin pigment in some or all of the feathers rather than an absence of melanin in the entire body.

Even the partial reduction of pigment can serve similar disadvantages as albinism since animals with leucism are easier to spot by predators and may not be recognized or accepted by other members of the species. Leucistic traits in birds may cause feathers to weaken and affect flight, as well.

Are Leucism and Albinism Common in Animals?

Albinism is an extremely rare condition in wildlife that occurs at birth. Researchers estimate the rate of albinism in animals to be anywhere from 1 in 20,000 to 1 in 1 million, though it's believed to be more common in bird, reptile, and amphibian species.

Since individual animals with albinism tend to have minimal or no vision and solid white skin or fur, making them more susceptible to predation, the animals are less likely to survive long enough to breed and pass the genetic condition on to offspring.

Leucism is also rare in animals, though it’s more common than albinism. The reduction in color still makes them more vulnerable due to their inability to camouflage or to blend in with the rest of their population, but it's not necessarily a death sentence, depending on severity.