The term tarpan (Equus ferus ferus ) refers to free-ranging horses of the Russian steppe from the 18th to the 20th century. It is generally unknown whether those horses represented genuine wild horses, feral domestic horses or hybrids.The last individual believed to be a tarpan died in captivity in the Russian Empire during 1909.
Beginning in the 1930s, several attempts were made to develop horses that looked like tarpans through selective breeding, called "breeding back" by advocates. The breeds that resulted included the Heck horse, the Hegardt or Stroebel's horse, and a derivation of the Konik breed, all of which have a primitive appearance, particularly in having the grullo coat colour. Some of these horses are now commercially promoted as "tarpans", although such animals are only domestic breeds and not the wild animal themselves.
The name "tarpan" or "tarpani" derives from a Turkic language (Kazakh or Kyrgyz) name meaning "wild horse". The Tatars and the Cossacks distinguished the wild horse from the feral horse; the latter was called Takja or Muzin.
Traditionally, two tarpan subtypes have been proposed, the forest tarpan and steppe tarpan, although there seem to be only minor differences in type. The general view is that there was only one subspecies, the tarpan, Equus ferus ferus. The last individual, which died in captivity in 1909, was between 140 and 145 centimetres (55 and 57 in) tall at the shoulders, or about 14 hands, and had a thick, falling mane, a grullo coat colour, dark legs, and primitive markings, including a dorsal stripe and shoulder stripes.
A number of coat color genotypes have been identified within European wild horses from the Pleistocene and Holocene: those creating bay, black and leopard complex are known from the wild horse population in Europe and were depicted in cave paintings of wild horses during the Pleistocene. The dun gene, a dilution gene seen in Przewalski's horse that also creates the grullo or "blue dun" coat seen in the Konik, has not yet been studied in European wild horses. It is likely that at least some wild horses had a dun coat.
Whether or not the horses called tarpan had a standing mane like wild equines, or a falling mane like domestic horses cannot be ascertained anymore as historic reports have not been unambiguous on this subject.
The appearance of European wild horses may be reconstructed with genetic, osteologic and historic data. One genetic study suggests that bay was the predominant color in European wild horses. During the Mesolithic, a gene coding a black coat color appeared on the Iberian peninsula. This color spread east but was less common than bay in the investigated sample and never reached Siberia. Bay in combination with dun results in the "bay dun" color seen in Przewalski's horses; black with dun creates the grullo coat. A loss of the dun dilution may have been advantageous in more forested western European landscapes, as dark colors were a better camouflage in forests. Pangaré or "mealy" coloration, a characteristic of other wild equines, might have been present in at least some European wild horses, as historic accounts report a light belly.
Historic references describing the tarpan report that most of them were of a black dun (grullo, "blue dun") colour, while also black individuals and also domestic colours like white legs or greys have been reported. Because of that, some contemporaneous authors, such as Peter Pallas, believed tarpans to be escaped farm horses.
Three attempts have been made to use selective breeding to create a type of horse that resembles the tarpan phenotype, though recreating an extinct subspecies is not genetically possible with current technology. In 1936, Polish university professor Tadeusz Vetulani selected Polish farm horses that were formerly known as Panje horses (now called Konik) and that he believed resembled the historic tarpan and started a selective breeding program. Although his breeding attempt is well known, it made only a minor contribution to the modern Konik stock, which clusters genetically with other domestic horse breeds, including those as diverse as the Mongolian horse and the Thoroughbred.
In the early 1930s, Berlin Zoo Director Lutz Heck and Heinz Heck of the Munich Zoo began a program crossbreeding Koniks with Przewalski horses, Gotland ponies, and Icelandic horses. By the 1960s they produced the Heck horse. In the mid-1960s, Harry Hegard started a similar program in the United States using mustangs and local working ranch horses that has resulted in the Hegardt or Stroebel's horse.
