Before the solid-coated and dappled thoroughbreds that usually come to mind when we hear the word "horse," there was the zebra. One of the oldest members of the horse family, the African zebra seems far more exotic than common horses and donkeys. However, it closely resembles the earliest equine ancestors [source: Groves].
Zoologists have yet to unravel all of the genetic mysteries that lie behind the zebra's signature striped suit. The alternating color pattern works well with its native environment, deflecting up to 70 percent of the heat that hits its body [source: The International Museum of the Horse]. The arrangement of the stripes adds another intriguing dimension to the animal's biology since each zebra has a completely unique design. In particular, the stripes on its shoulders, or withers, contain the most individualized markings [source: The International Museum of the Horse].
If you wear a zebra-print outfit in a crowd, it nearly guarantees that someone will easily spot you. In the jungle, however, a zebra's stripes actually work as a camouflage to deter its main predators: lions and hyenas. Since the animals herd together, experts believe that the mass of stripes can confuse the predators by acting as an optical illusion that blends their figures together. Consequently, a group of 10 zebras may look like a giant striped blob that a lion wouldn't want to take on solo. For more detailed information about this natural disguise, read "How do a zebra's stripes act as camouflage?"
By and large, these ungulates -- or hoofed animals -- prefer to pal around together rather than alone, migrating as far as 300 miles (482 kilometers) to graze [source: Holland]. Even before mating, clusters of bachelor zebras will eat together. Then, stallions will lead a number of female zebras, called a harem. Their unique stripes promote this social behavior since they can tell each other apart.
Even if you aren't an equine specialist, you can easily spot a zebra from its telltale black-and-white color scheme. But which is it: black on white or white on black? Find out on the next page.
What Color Is a Zebra?
Genetics determine the variety of stripes in zebras. While the specific processing of determining this striping pattern isn't known, it has something to do with selective pigmentation. Melanocyte skin cells produce the pigments that color the fur. Certain chemical messengers regulate which melanocytes deliver their pigment to the zebra [source: Camazine]. Mathematical models haven't been able to accurately simulate the development of the pattern, but we do know that it takes place during the embryonic phase [source: The Development of Zebra Striping Pattern].
Speaking of stripes, that brings us to the age-old question: What color is a zebra? If you research this answer, you'll quickly discover many conflicting perspectives. But Lisa Smith, Curator of Large Mammals at Zoo Atlanta, reports that the coat is "often described as black with white stripes." This makes sense since the pattern is a result of pigment activation (black) and inhibition (white). That means black is the actual color of the fur, and the white patches are simply the areas that lack pigmentation [source: Camazine]. To top it off, most zebras have dark skin beneath their fur [source: Smith].
Although zebras share similar stripe patterns and the same general appearance, a closer examination of their coats reveals distinct differences among the three existing species:
- Burchell's/plains zebras (Equus burchelli): These are the most populous zebra species, found in northern Kenya. Their broader stripes fade to gray, called shadow striping, as they move down the body. Their legs feature a lot of white as well.
- Grevy's zebras (Equus greyvi): These zebras have the largest build and are found in northern Kenya as well. They have narrower stripes with definitive black stripes slicing down the middle of their backs and white bellies. Because drought and an increasing human population have severely reduced their numbers, the World Conservation Union lists Grevy's zebra as an endangered species [source: National Zoo].
- Mountain zebras (Equus zebra): Found in southern Angola and Namibia, mountain zebras are the least common of the species. A square flap of skin on their throats distinguish these zebras from the other two species. They also sport wide stripes against a cream-colored background.
To learn more about the secrets of zebra's stripes and other animals, visit the links on the next page.
Related HowStuffWorks Articles
More Great Links
- Camazine, Scott. "Patterns in Nature." Natural History Magazine. June 2003. (July 14, 2008)http://www.naturalhistorymag.com/0603/0603_feature.html
- "Grevy's Zebra." Smithsonian National Zoological Park. (July 14, 2008)http://nationalzoo.si.edu/Animals/AfricanSavanna/fact-gzebra.cfm
- Groves, Colin P. "Horses, Asses and Zebras." Ralph Curtis Books. 1974.
- Holland, Jennifer Steinberg. "Zebras: Born to Roam." National Geographic Magazine. September 2003. (July 11, 2008)http://ngm.nationalgeographic.com/ngm/0309/feature2/index.html?fs=video.nationalgeographic.com&fs=plasma.nationalgeographic.com
- Murray, James Dickson. "Mathematical Biology." Springer. 2002. (July 11, 2008)http://books.google.com/books?id=VmCQ28GWqE0C
- "Mammals: Zebra." San Diego Zoo. (July 11, 2008)http://www.sandiegozoo.org/animalbytes/t-zebra.html
- Smith, Lisa. Personal Correspondence. Conducted July 14, 2008.
- "The Development of Zebra Striping Pattern." Swarthmore Virtual Library of Developmental Biology. Updated Dec. 22, 1998. (July 11, 2008)http://zygote.swarthmore.edu/ecto10.html
- "Zebra." International Museum of the Horse. (July 11, 2008)http://www.imh.org/museum/breeds.php?pageid=8&breed=103