Creatures Without Color

This past spring, the Borneo Orangutan Survival Foundation mounted a special rescue mission. The foundation’s conservationists saved a young orangutan being kept in a cramped cage in a village on the Southeast Asian island of Borneo. Orangutans are endangered, so the group aims to protect as many as they can. But this one was even more special than usual. That’s because instead of having an orangutan’s typical reddish fur, she was completely white. The ape’s rescuers named her Alba, Latin for “white.” She’s the only known albino orangutan in the world.

Albinism is an inherited condition in which the body can’t properly produce colored chemical compounds called pigments. As a result, the skin, hair, fur, feathers, or scales of albino animals are mostly colorless. Without their typical coloration, these animals don’t usually fare well in the wild.

This past spring, the Borneo Orangutan Survival Foundation carried out a special rescue mission. The foundation’s conservationists saved a young orangutan. She was being kept in a small cage in a village on the Southeast Asian island of Borneo. Orangutans are endangered, so the group wants to protect as many as it can. But this one was even more special than usual. She didn’t have reddish fur like orangutans normally do. She was completely white. The ape’s rescuers named her Alba, Latin for “white.” She’s the only known albino orangutan in the world.

Albinism is a condition passed down through the parents. Normally, the body makes colored chemical compounds called pigments. But animals with albinism can’t properly produce these compounds. So their skin, hair, fur, feathers, or scales are mostly colorless. These animals don’t usually do well in the wild without their normal coloration.

Albinism has been documented in at least 300 animal species in North America and in a wide range of species around the globe. But it tends to be rare—only one out of many thousands of individuals might have this trait. Albinism occurs in people as well. About one in 20,000 people worldwide have albinism, though certain populations have higher or lower rates.

Part of the reason for albinism’s rarity has to do with the genetics of this trait. Units of hereditary material, called genes, control the production of pigments. Pigment genes have different versions, called alleles. People and most animals inherit one allele from each parent. Alleles associated with albinism are recessive, which means that an organism will show the trait only if it inherits two albinism alleles.

Albinism has been found in at least 300 animal species in North America. It’s also found in a wide range of species around the globe. But this trait tends to be rare. Only one out of many thousands of animals might have it. Albinism also occurs in people. About one in 20,000 people around the world have albinism. Some groups have higher or lower rates.

Why is albinism so rare? Part of it has to do with its genetics. Genes (units of hereditary material) control the making of pigments. Pigment genes have different forms, called alleles. People and most animals get one allele from each parent. Alleles linked with albinism are recessive. That means that an organism will show the trait only if it gets two albinism alleles. 

Many people—about 1 in 70—and many animals carry one allele for albinism and one for typical pigmentation. These individuals are carriers for the trait. Because albinism is recessive, there is nothing unusual about their looks. But two typical-looking carriers can have offspring with albinism (see Passing On Genes).

Many animals carry one allele for albinism and one for usual pigmentation. So do about 1 in 70 people. These individuals are carriers for the trait. They don’t look unusual, because albinism is recessive. But two ordinary-looking carriers can have offspring with albinism (see Passing On Genes). 

Some evidence suggests that animals born with albinism don’t fare well in the wild. One reason is that a stark-white animal stands out in its natural habitat, unlike an ordinary-colored companion that blends in with its surroundings. That makes it easy for predators to spot and catch an albino animal. Some studies, for example, have found that owls are more likely to pounce on albino mice than brown ones.

Some data suggests that animals born with albinism don’t do well in the wild. An animal with usual colors might blend in with its surroundings. An all-white animal might stand out more. That makes it easy for predators to spot and catch an albino animal. For example, some studies show that owls are more likely to pounce on albino mice than brown ones. 

Lack of color brings other problems too. Albino birds often have trouble finding a mate and are sometimes even attacked by members of their own flock. The birds may not recognize an individual lacking the usual markings as the same species.

The sun is another potential danger for albino animals. The pigment melanin—which creates tan, brown, or black coloration in many animals—can be important for protection from the sun’s damaging ultraviolet (UV) rays. In people, exposure to the sun signals the body to pump up production of this pigment. That causes skin to tan, which provides some defense against burns. Animals and people with albinism, though, don’t produce this pigment. That makes them especially susceptible to sunburns and possibly deadly skin cancers.

Lack of color brings other problems too. Albino birds often have trouble finding a mate. Sometimes they’re even attacked by members of their own flock. An albino bird doesn’t have the usual markings, so the other birds may not know it’s the same species.

The sun can be another danger for albino animals. The pigment melanin creates tan, brown, or black coloration in many animals. It also protects animals from the sun’s harmful ultraviolet (UV) rays. When people are exposed to the sun, the body pumps up production of this pigment. That causes skin to tan, which provides some defense against burns. But animals and people with albinism don’t produce this pigment. That raises the danger of sunburns and possibly deadly skin cancers. 

Albino crocodiles, snakes, and lizards face special difficulties. Reptiles are cold-blooded—they rely on external heat to regulate their body temperatures and often bask in the sun to warm themselves up. Albino reptiles can’t keep warm the typical way without the risk of sunburn. They tend to do better in captivity, where caretakers can provide artificial heat sources like special heated stones to keep them warm. 

Albino crocodiles, snakes, and lizards face special problems. Reptiles are cold-blooded. That means they need heat from outside their bodies to control their temperatures. They often lie in the sun to warm themselves up. Albino reptiles risk sunburn when they keep warm the way they usually do. They tend to do better in captivity. Caretakers can provide artificial heat sources like special heated stones to keep them warm. 

Just because an animal’s coloring is pale doesn’t mean it has inherited albinism. “There are many naturally white animals, such as polar bears, that aren’t albinos,” says Murray Brilliant, a geneticist at the Marshfield Clinic Research Institute in Wisconsin. One big clue that an animal isn’t albino is dark-colored eyes. True albino animals don’t produce dark eye pigments.

An animal may be pale, but that doesn’t mean it has albinism. “There are many naturally white animals, such as polar bears, that aren’t albinos,” says Murray Brilliant. He’s a geneticist at the Marshfield Clinic Research Institute in Wisconsin. Dark-colored eyes are a big clue that an animal isn’t albino. True albino animals don’t make dark eye pigments. 

An ongoing study of squirrels across the U.S. is showing how the occurrence of white fur compares with that of true albinism. Of the squirrels reported to have white fur, the survey found that about 80 percent have dark eyes. Only about 20 percent have red or pink eyes that show they’re truly albino. “That pink color comes from blood vessels in the back of the eye,” says Brilliant. The same is true for albino rabbits and mice.

Other species with albinism, including people and orangutans like Alba, don’t have pink eyes—although camera flashes can sometimes make it look that way in photos. Since humans and other primates have more types of eye pigments than other animals, individuals with albinism tend to have eyes that appear very light blue.

A study of squirrels is going on across the U.S. It’s showing how many squirrels have white fur, compared with how many have true albinism. The study found that about 80 percent of white squirrels have dark eyes. Only about 20 percent have red or pink eyes. That shows they’re truly albino. “That pink color comes from blood vessels in the back of the eye,” says Brilliant. It’s the same for other albino rodents, like rabbits and mice.

Other species with albinism don’t have pink eyes. That includes people and orangutans like Alba. Camera flashes can sometimes make their eyes look pink in photos. But humans and other primates have more types of eye pigments than other animals. So individuals with albinism tend to have very light blue eyes. 

Eye pigments and the molecules involved in making pigments are important for healthy eye development. Without them, animals with albinism can have serious vision problems, which can make spotting prey or predators difficult.

People with albinism often have vision problems too. In his research, Brilliant has identified alleles associated with albinism in people. “Now we’re working on understanding how the genes function and developing therapies to enhance vision in people with albinism,” he says.

Eye pigments are important for healthy eye growth. So are the chemicals involved in making these pigments. Without them, animals with albinism can have serious vision problems. That can make it hard to spot prey or predators.

People with albinism often have vision problems too. In his research, Brilliant has found alleles linked to albinism in people. “Now we’re working on understanding how the genes function and developing therapies to enhance vision in people with albinism,” he says. 

Poor vision is just one of the problems that would put Alba, the albino orangutan, at risk in the wild. To keep her safe, conservationists plan to set up a spacious reserve for her to live in with three orangutan friends—a fitting home for a truly unique animal.

Poor vision is just one of the problems facing Alba, the albino orangutan. She would be at risk in the wild. To keep her safe, conservationists plan to set up a large reserve. She’ll live there with three orangutan friends. It will be a fitting home for a unique animal.