Albinism appears in approximately three hundred
animal species in North America. This is a rare inherited absence of
pigmentation or coloration. It is speculated that factors other than genetic
ones, such as age or diet, may cause this abnormality. Plus, fish eggs exposed
to heavy metals, like copper or mercury, can produce albinos.
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| Albino rat photo by Hailey Scalia, age 8 |
Initially, verification of albinism relies on
pigmentation and coloration. For instance, the majority of mammals have just
the melanin pigment, but many animals have pigments other than melanin. Some,
like certain butterflies, have pigments and structural colors. Such diversity
hinders interpretation!
Generally, defining traits are white hair or fur,
skin, feathers, scales, and cuticle. Yet, not all albinos are pure white! Eyes
are commonly red or pink resulting from the lack of pigment in the iris which
exposes the blood vessels of the retina. However, blue or green eyes do
surface.
Misleading are animals mistaken for albinos, such as
those with leucism, a partial loss of pigmentation. This happens to many
creatures—like tigers, hawks, fish! They emerge white, pale, or patchy but
usually have normal eyes. How about flamingos which appear white if they have
insufficient red carotenoid pigments in their food?
In
reptiles, birds, and amphibians, albinism is more prevalent. Large snakes like
diamondbacks and boas tend to be affected—often pinkish and yellowish. The
occurrence is 1 in 1800 birds, often house swallows and American robins. In
mammals, it is 1 in 10,000.
Unique are albino bottlenose dolphins. Only 15 were
reported since 1962. In 2007, a pink one appeared in a Louisiana lake—pink
because blood vessels were exposed through blubber and unpigmented skin. The
last sighting of an apparent true albino was in December, 2014, in the Indian
River, right here in Brevard County!
The
pet industry thrives on breeding albinos, especially Norway rats (also named
brown rats); moreover, they are esteemed laboratory rats. Other favorites are
albino Burmese pythons, patterned white with yellow and orange. Often bred, but
scarce, are blue-eyed leucistic Burmese pythons; though non-albinos, they are
equally stunning with their white bodies void of markings. In 2013, a 13-foot
albino Burmese python was captured in Hialeah, Florida. An escaped pet?
Captivity increases survival for albinos. In the
wilds, life is challenged by such obstacles as exclusion from family, lack of
camouflage, impaired hearing and vision, and sun sensitivity. Alligators might
survive only 24 hours. Perplexing are albino squirrels which seemingly survive
as well as pigmented species!
Tame
or wild, albinos intrigue! On a nature walk, a little scrutiny might reveal an
albino land snail gliding by.
