Zebras are one of the few members of the Equidae family that haven't been fully domesticated. Zebras belong to the genus Equus, and as such they can crossbreed with other Equus species. The resulting hybrid is almost always sterile. The three species of zebras have between 44 and 62 chromosomes, donkeys have 62, and horses have 64. In case you don't recall what they look like, here are typical zebras.
A crossbred zebra is known as a zebroid or zebra mule. Zebroids were originally bred as pack animals in Africa for practical reasons. They are more resistant to certain diseases, such as sleeping sickness, than horses or donkeys. Zebroids for domestic use are bred for the look of a zebra, tempered by the domesticated nature of a horse or donkey. The crossbreed is often shaped like the non-zebra parent, which makes finding a proper saddle simpler than trying to ride a zebra. Zebra stripes tend to show up on at least part of the hybrid's body.
A zony is a cross between a zebra and a pony. This zony's name is Ziggy; he lives at a farm in Knights Ferry, CA with his camel friend. (image credit: Jenguin)
Alex is a foal with a zebra mother and a donkey father. This cross is called a zebret or zebrinny (image credit: Chris Brandis/AP)
A zebra stallion bred with a female donkey would be called a zedonk or zonkey. The exact parentage of the petting zoo zebroid pictured here is uncertain, but it is a donkey/zebra cross.
This photograph caused many people to cry "Photoshop!" Eclyse is a zorse, meaning her father was a zebra, and her mother was a horse. Her markings are unusual even for a zorse. In most animal hybrids, you see a gradual blending of traits from each parent. In this case, there is no question about which body part came from each parent!
A zebroid with a horse for a father and a zebra mother is called a hebra. They are much rarer then zorses, and look very different from a zorse. This hebra lives at the Colchester Zoo in England. (image credit: Dcgi)
The quagga looks like a cross between a zebra and some other animal, but it was a type of zebra. The word "quagga" was used interchangably with "zebra" when Europeans colonized Africa. The quagga was identified as a seperate species in 1788, but that didn't stop hunters and settlers from killing them for meat, hides, and to preserve grazing land. The quagga became extinct when the last one died in captivity on August 12, 1883. DNA analysis of the preserved remains of several quaggas revealed that it was not a separate species after all, but a subspecies of the Plains zebra. The Quagga Project is selectively breeding Plains zebras with DNA similar to the quagga in order to bring the quagga back and reintroduce it to protected preserves in its former habitat in South Africa.
This animal looks like a cross between a zebra and a giraffe! But it's more of a red herring here. The okapi is an African rainforest relative of the giraffe that just happens to have zebra-striped legs. Although known to locals, the okapi was considered a mythical animal among Europeans until it was classified in the twentieth century. Okapis are neither descended from nor related to zebras. (image credit: Mark Pellegrini)
This article was inspired by a series of posts last year at Neatorama.