The Zebra's Stripes
by Annamaria Tadlock
Images from Wikipedia, click on images for copyright info

 

Native to africa, the zebra is known for its stripes.
But whats the science behind the stripes?

Like our fingerprints, each zebra's pattern of striping is unique-- it may help zebras to identify each other. According to the San Diego Zoo, zebras are attracted so stripes-- if there are stripes painted on a wall, zebras will stand next to it!

Their bold black-and-white pattern is thought to help them stay camoflouged. Lions, the main predator of the zebra, are color blind so the vertical stripes help them blend in with grasses.
Also, when a herd of zebras move, it's hard to tell when one zebra ends and another begins! That may make it hard for a predator to track and kill an individual.
The stripes also confuse the blood-sucking Tsetse fly.

Stripes vary with different species of zebra, too.
The further south you go in Africa, the wider the stripes get!
The zebra with the narrowest stripes is the Grevy's Zebra. It is the biggest species of zebra standing 13.3-15.3 hands high.

Grevy's Sebra, from Wikipedia

The Plains Zebra-- also called the Common or Burchell's Zebra, has wider stripes. It stands around 13.2 hands high and is the mose widespread of the zebra species.

Plains Zebra, source: Wikipedia

The last species of zebra, the Mountain Zebra, has very wide stripes and stands only 3-4 feet hight (maximum of 12 hands). They also have a dewlap on their neck.

Mountain Zebra, from Wikipedia

Are they black with white stripes, or white with black? Some say it depends on how you look at it. But it's probably a combination of factors that make the zebra striped-- a pattern of dark striping, plus another pattern that makes light hair.

In most horse color patterns, white is a secondary pattern imposed over a base color. For example, a pinto is never white with black spots, no matter how small the black area is; it is always black with white patterns.

In most horse colors, white hairs appear over pink skin. Zebras, however, have black skin. So their base color is probably dark with a white pattern.

However, when zebras are bred to horses-- the offspring is called a zorse-- the babies are often horse-colored with darker stripes!
The striping isn't always black, however; sometimes it is just a darker version of the base color (for example, a chestnut zorse will have deeper red stripes).

This shows that the black striping is a dominant pattern that can be imposed over other colors.

I also saw one zorse (a bay) who had darker stripes on its head, and in between the dark stripes, were lighter bay stripes!
So perhaps the pattern isn't simply two separate black-and-white patterns, but a genetic mechanism that repositions the pigment into darker and lighter bands.

This might be similar to how the dun gene acts in the horse. Zorse breeders have noted that dun mares crossed with zebra stallions tend to have nicely striped foals.

The dun pattern redistributes the pigment into darker stripes and lighter areas and can sometimes make very distrinct striping on the horse's legs, back, and withers.