This short essay on the origins of European wild horses and the naming of their living and extinct relatives was first published here in November 2010. The author is a Natural Sciences graduate from the University of Perugia, Italy, whose first paper on Upper Paleolithic art was published in the 2010 issue of PaleoAnthropology.
We don’t know how many species or subspecies of wild horses lived in Europe and Asia when early domestication attempts began, but we do know that only one of them escaped or resisted domestication, survived captivity, and is still living in the wild today: Przewalski horses (Equus ferus przewalskii), also known as Mongolian or Asian wild horses.
We also don’t know how many species or subspecies were domesticated. Many authors think that Przewalski horses were not among them, and point instead to an extinct subspecies of European wild horse (Equus ferus ferus) of which the horses known as tarpans may have been the last surviving population. This may explain why the word “tarpan” is widely used today as a synonym for wild horse, but where did the tarpans really come from?
There are two views on this, as found in the existing literature. According to the first view, the horses known as tarpans were the direct descendants of a wild population from Pleistocene times, regardless of how much they later mixed, or were mixed, with domestic or feral horses, whereas the second view holds that they were nothing more than feral horses, no matter how ancient. From the pages of Mammal Species of the World, Grubb (2005) reminds us that material evidence that the tarpan was a wild horse, and one distinct from the Przewalski horse, “is limited to osteological material of two specimens and it has not been reliably identified with Pleistocene or Holocene local populations,” so it is not surprising that “its status as a wild rather than a feral form is disputed.” This is how Kowalski (1967) summed up what we know about wild horses in Europe and Asia:
In the open areas of the late Pleistocene, the wild horse was very common and was a principal prey of Paleolithic hunters. In the postglacial, the range of the wild horse contracted, beginning with western Europe, and . . . now lives only in the semideserts of Central Asia . . . . Historical data prove the existence of wild horses in the Ukrainian steppes as late as the middle of the nineteenth century. These horses were described as a separate species . . . but they were more probably feral . . . . The postglacial development of forests made the existence of the wild horse in western and central Europe impossible, and the final limitation of its area to the semideserts of central Asia was the result of predation by man.
The “historical data” referred to above are a series of references from the eighteenth and nineteenth centuries where the tarpan was described as “a small animal, having a mouse-dun coat with a light underbelly, sooty to black limbs from the knees and hocks down, a short, frizzled mane, and a tail with short dock hair.” This brief summary was given by Olsen (2006) who then remarked:
In fact, in most features the tarpan was very similar in appearance to the Przewalski horse, except that the coat was grayer and apparently turned very light in the winter.
The similarity evoked in this remark may be taken as evidence that the tarpan was indeed a wild horse, but may also suggest a third possible answer to the question of where the tarpans came from. The key point is that the coat of Przewalski horses can also turn lighter in winter, although this seasonal character is rarely mentioned in the literature (Groves pers. comm.) maybe because it has only been observed in some variants. What this leaves us with is only the summer coat color difference, so I wonder if in some of the early sightings the witness actually saw Przewalski horses instead? Yet another possibility is that the tarpans were a population of Przewalski horses that, at the western end of their range, had mixed with domestic or feral horses. For example, genetic studies suggest that interbreeding may have occurred in the past between Przewalski horse males and domestic females (Lau et al. 2009), and if this was the case than such a pattern was never lost because that is the reason why tarpans were ultimately hunted to extinction (Bököny 1974).
Even if their status was uncertain, as many as three attempts to “breed back” the tarpans took place after their disappearance. In Poland, Vetulani used selected local domestic horses, among which may have lived the descendants of the last free-living “forest tarpans.” The type of horses he selected and bred he called “Konik,” Polish for “little horse,” and the same name is still used today. In Germany, the Heck brothers used Przewalski horses and four domestic breeds, including Koniks, and their result is known as Heck horse (Bunzel-Drüke 2001). The contribution from Koniks, however significant, is clearly not enough to make Heck horses the same as the vanished “tarpans”, and yet this is how they have since been known in Germany, as well as in North America where a few of them were imported beginning in the 1950s. In the 1960s, in central Oregon, Harry Hegardt began a new backbreeding program using wild mustangs from the American west, which are likely to descend from the horses of the Spanish conquistadores, which in turn may have been closely related to the tarpan. However, even this connection would hardly make Hegardt horses—however unique and fascinating their story—the same as “tarpans,” as they were described in the press.
A view of the primeval forest in Bialowieza National Park, Poland, where the horses known as tarpans were last seen between the late 18th and early 19th century.
Whether the horses known as tarpans were truly wild, a mix of wild and feral horses, or a line of Przewalski horses mixed with domestic or feral horses, we should call “tarpan” only the real ones, the horses that were seen in the forests and steppes of central and eastern Europe until the end of the 19th century without assuming that they had been living in the wild, in the same region, since the end of the last glaciation—Andrea Castelli
NOTE: For scientific names, I have followed Groves (1994) who recognized three subspecies, the two given in parentheses above plus an unnamed “Swedish form.” This does not rule out that there may have been only one subspecies (a species, that is) or two or more species, but does provide a useful taxonomy.
REFERENCES
Bököny, S. 1974. History of Domestic Mammals in Central and Eastern Europe. Akadémiai Kiadó, Budapest.
Bunzel-Drüke, M. 2001. Ecological Substitutes for Wild Horse (Equus ferus Boddaert, 1785 = E. przewalskii Poljakov, 1881) and Aurochs (Bos primigenius Bojanus, 1827). Corrected reprint at http://grazers.wordpress.com/
Groves, C. P. 1994. Morphology, Habitat and Taxonomy. In Boyd, L. and Houpt, K. A. (Eds.) Przewalski’s Horse: The History and Biology of an Endangered Species, pp. 39–59. SUNY Press, Albany, NY.
Grubb, P. 2005. Equus caballus. In Wilson, D. E. and Reeder, D. M. (Eds.) Mammal Species of the World: A Taxonomic and Geographic Reference. 3rd ed., vol. 1, pp. 630–631. The John Hopkins University Press, Baltimore. Available at http://www.bucknell.edu/msw3/
Guthrie, D. R. 2005. The Nature of Paleolithic Art. University of Chicago Press, Chicago.
Kowalski, K. 1967. The Pleistocene extinction of mammals in Europe. In Martin, P. and Wright, S. (Eds.) Pleistocene Extinctions, pp. 349–365. Yale University Press, New Haven.
Lau, A. N., Peng, L., Goto, H., Chemnick, L., Ryder, O. A., and Makova, K. D. 2009. Horse Domestication and Conservation Genetics of Przewalski’s Horse Inferred from Sex Chromosomal and Autosomal Sequences. Molecular Biology and Evolution 26(1): 199–208. Available at http://mbe.oxfordjournals.org/content/26/1/199 (PDF)
Olsen, S. L. 2006. Early horse domestication on the Eurasian steppe. In Zeder, M. A., Bradley, D. G., Emshwiller, E. and Smith, B. D. (Eds.) Documenting Domestication: New Genetic and Archaeological Paradigms, pp. 245–269. University of California Press, Berkeley.
Absolutely wonderful article!
Reblogged this on EQUILIBRE Gaiá.