A zebroid or zorse, is the offspring of any cross between a zebra and any other equine: essentially, a zebra hybrid.
What is a zebroid?
Zebroids have been bred since the 19th century. Charles Darwin noted several zebra hybrids in his works. Zebroid is the term generally used for all zebra hybrids. The different hybrids are generally named using a portmanteau of the sire’s name and the dam’s name.
There is generally no distinction made as to which zebra species is used. Many times when zebras are crossbred, they develop some form of dwarfism. Breeding of different branches of the equine family, which does not occur in the wild, generally results in infertile offspring. The combination of sire and dam also affects the offspring phenotype.
Interest in zebra crosses continued in the 1970s. In 1973 a cross between a zebra and a donkey was foaled at the Jerusalem Zoo. They called it a “hamzab.” In the 1970s, the Colchester Zoo in England bred zedonks, at first by accident and later to create a disease-resistant riding and draft animal.
The experiment was discontinued when zoos became more conservation-minded. A number of hybrids were kept at the zoo after this; the last died in 2009. One adult still remains at the tourist attraction of Groombridge Place near Tunbridge Wells in Kent.
Donkeys and wild equids have different numbers of chromosomes. A donkey has 62 chromosomes; the zebra has between 32 and 46, depending on species. In spite of this difference, viable hybrids are possible, provided the gene combination in the hybrid allows for embryonic development to birth.
Image: Von Kumana, CC BY 2.0
Text: Wikipedia contributors. “Zebroid.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 5 Sep. 2017. Web. 7 Sep. 2017.