Equine hair analysis: Combing the evidence about past and present Przewalski’s horses in Asia’s Gobi Desert

Fran Jurga
Jul 21, 2017 · 4 min read

Reintroduced Przewalski’s horses have a different diet today than their ancestors

If you’re a horse, you eat grass. This is true for domestic horses as well as for wild horses in the Gobi Desert. But has it always been the case?

A team of researchers from the Research Institute of Wildlife Ecology from the University of Veterinary Medicine of Vienna, Austria learned through tail hair analysis that before pre-extinction wild Przewalski’s horses enjoyed a different diet than their reintroduced descendants do today.

Thanks to improved human attitudes toward these fascinating horses, they now have access to richer pastures. In former times, wild horses in Asia were hunted and chased away into less productive habitats. The study was published in Scientific Reports and on the publisher’s website, nature.com.

The Przewalski’s horse, also called “Takhi” or the “Mongolian wild horse”, is the only remaining wild horse species on earth. In 1969, the last Przewalskis were officially declared extinct in the wild. However, a few animals survived in captivity. In 1992, some of these captive-bred horses were returned to the Asian wilds.

Petra Kaczensky and Martina Burnik Šturm from the Research Institute of Wildlife Ecology at the University of Veterinary Medicine of Vienna have collected data showing that, before their extinction in the wild, Przewalski’s horses were on a mixed diet. In summer, they only ate grass; in winter they also grazed on less nutritious bushes. Analysis of recently gathered hair shows that, since their reintroduction, the animals only eat high-quality grass throughout the year.

“We explain this dietary shift by an improved human attitude. In the past, humans considered Przewalski’s horses as pasture competitors and hunted them as a food source. The nutritious pastures were reserved for domestic sheep and cattle. Thus, access to pastures in winter was difficult for wild horses. Shrubs and bushes were the only alternative,” explains Martina Burnik Šturm, one of the lead authors.

Przewalski’s horses are “holy animals” in Mongolia today

Unlike in former times, Przewalski’s horses are now worshiped as “holy animals” in the Gobi Desert. They are fully protected and are no longer hunted by humans. “The wild horses can now feed on grass throughout the year because humans allow it,” says wildlife biologist and lead author Petra Kaczensky.

Habitat in the Gobi Desert has hardly changed

In the last 120 years, the habitat of the wild horses in Southwest Gobi has hardly changed. The available food resources have remained the same. But the social acceptance of Przewalski’s horses has changed.

The situation is different for Asian wild asses, or “Khulan”, which also live in the Gobi Desert. Although they are also a protected species, they are less appreciated than wild horses among the people. The wild asses are still hunted by humans and chased away from nutritious pastures. They feed on grass only during summer, but in winter eat mainly bushes and shrubs, jsut as they, and the Przewalski’s horses, had to in the past.

“In Khulan, we clearly see the influence of humans on the animals’ way of life. The attitude towards the animals in society significantly influences their feeding behavior,” said Kaczensky.

Diet has been detected in hair

A common method to understand the animals’ ecology and behavior is to analyze the chemical composition of its hair. This involves the analysis of stable isotopes, which are variants of the same chemical element with different atomic weights, containing the same number of protons, but different number of neutrons. The isotope ratios of hydrogen, oxygen, carbon and nitrogen in a sample provide essential information on the animals’ water uptake, nutrition and habitat.

Hair samples from historic Przewalski´s horses and Khulan have been provided by the researchers from the Zoological Museums in St. Petersburg and Moscow. “These more than 120-year-old hair samples are as useful and informative as freshly collected ones,” explains Burnik Šturm.

How does the measurement of hair isotopes work?

For the isotope analysis, the tail hair is cut into one centimeter long segments and placed individually in little tin or silver cups before being burnt at high temperature. Isotopes are then measured in the developing gases using mass spectrometry, a method to sort individual atoms by mass.

The research has been published: The article “Stable isotopes reveal diet shift from pre-extinction to reintroduced Przewalski’s horses” by Petra Kaczensky, Martina Burnik Šturm, Mikhail V. Sablin, Christian C. Voigt, Steve Smith, Oyunsaikhan Ganbaatar, Boglarka Balint, Chris Walzer and Natalia N. Spasskaya appears in Scientific Reports. The article is published under a Creative Commons Attribution 4.0 International License (Open Access).

Find the article at this link.

Information provided by the University of Vienna was used to create this article.

Fran from America

When I travel, people often fail to recognize my name. I can read their minds over a handshake: “Who on earth is Fran Jurga?” Then hours later they blurt, “Oh! You’re Fran!Fran from America!” Whoever she is, she has a lot of friends in the world; I’m lucky to look a lot like her!

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Fran Jurga

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Horsing around? Always! Catch up on “Fran from America” news about equestrian culture/media and horse health from the USA’s award-winning, globetrotting scribe.

Fran from America

When I travel, people often fail to recognize my name. I can read their minds over a handshake: “Who on earth is Fran Jurga?” Then hours later they blurt, “Oh! You’re Fran!Fran from America!” Whoever she is, she has a lot of friends in the world; I’m lucky to look a lot like her!

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