Sat. Jan 22nd, 2022

Aerial photo from a helicopter of a group of Burchells plains zebras (Equus quagga burchellii), Okavango Delta, Botswana. Source – Diego Deiso. CC SA 4.0.

Zebras are iconic for their distinctive black and white stripes, but have you ever wondered if zebras are white with black stripes or black with white stripes?

Zebras are African horses of the genus Equus (same as horses) and belongs to the subspecies Hippotigris. There are three living species, Grévy’s zebra (Equus grevyi), delete zebra (E. quagga), and the mountain zebra (E. zebra).

While the stripes on each zebra are unique to each individual, the three species each have their own stripe pattern. And if this is not enough to confuse you, for some zebras the darker parts of their skin are black, while others have browner color and some have only streaks on the body but not on the legs.

It is worth mentioning that there was a fourth species of zebra called the quagga (E. quagga quagga). This zebra was endemic to South Africa until it was hunted to extinction in the late 19th century by European settler settlers.

Quagga (Equus quagga quagga) is an extinct subspecies of zebra. Mare, London, Regent’s Park ZOO. The picture is dated 1870 and is the only specimen photographed alive. Source – Biodiversity Heritage Library / Frederick York (d. 1903). Public domain

It was long considered a separate species, but early genetic studies have supported that it is a subspecies of plains zebra. It had minimal streaks on its head, mane and neck, according to The Quagga Project.

But we still need an answer to the question

Despite all the differences in stripe patterns, all zebras have the same skin color: black, said Tim Caro, a behavioral and evolutionary ecologist and conservation biologist at the University of California, Davis.

Still, we need to look at the zebra’s melanocytes, or the cells that produce pigment for their fur, to determine if a zebra is white with black stripes or vice versa. And there are also the variations we see genetically.

So while zebras have black skin, different developmental processes determine their coat color, just as a fair-skinned person can have dark hair, Caro said. He adds that zebras actually have more light hair than dark, especially on the belly.

A flock of Grévy’s zebras (Equus grevyi), also known as the Imperial zebra. This is the largest living wild horseshoe and the most endangered of the three species of zebra. Source – “Daniel Fafard (Dreamdan)” CC SA 3.0.

This could lead us to believe that zebras are white with black stripes, right? But that is not the case, according to a 2005 review in the Journal of Investigative Dermatology.

Every piece of hair on a zebra – both light and dark – grows from a follicle filled with melanocyte cells. These cells produce a pigment called melanin that determines the color of hair and skin.

So much melanin leads to darker colors, like dark brown or black, while less melanin leads to lighter colors, such as hazel or blonde, Live Science reported earlier.

Zebra’s black fur is stuffed with melanin, but melanin is absent in white fur, essentially because the follicles that make up the streaks of white hair have “turned off” melanocytes, meaning they do not secrete pigment.

OK, are you ready for the answer? The production of melanin “shuts down during the development of white hair, but not of black hair,” Caro told in an email.

A harem of cape mountain zebras (Equus zebra). Source – Mountjoy. CC SA 2.0.

In other words, for zebras, the standard condition of the animals is to produce black hair, making them black with white stripes, according to Brittanica.

A study published in 2020 in the journal Proceedings of the Royal Society B showed that African horseflies landed less frequently on horses wearing striped or checkered rugs than they did on horses wearing solid-colored rugs. These biting flies can carry diseases that are fatal to zebras.

“There are very few mammals with contrasting stripes like a zebra,” Caro said. “The okapi has similar stripes on the bump, but in addition there is no other species that has completely clear black and white stripes. My guess is that the fly-repellent function is unique to horses because they are as susceptible to diseases as certain bites. flies carry in Africa. “

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