When you hear hoofbeats, you may be better off thinking of zebras than Przewalski’s horses. This critically endangered species is typically thought to be the last true member of the dwindling family of wild horses. But in the last several months, the Smithsonian Conservation Biology Institute (SCBI) ecstatically welcomed four new foals to its herd in Front Royal, Virginia.
Once native to Mongolia, China and Kazakhstan, Przewalski’s horse is believed to be a distant cousin of the modern domesticated horse. The two lineages split some 500,000 years ago, but still bear a remarkable physical resemblance to each other, save for a couple features like Przewalski horses’ smaller, stockier frame and a zebra-like mane. Przewalski’s horses can actually still reproduce with domestic breeds and produce fertile offspring.
These horses, named for the Russian explorer who first scientifically described them, are sometimes referred to as “p-horses” in lieu of the full Przewalski (pronounced sha-VAL-ski). P-horses galloped the steppes of Asia well into the 20th century—but were last seen in Mongolia’s Gobi Desert in the 1960s. Human interference, including poaching and encroachment on these horses’ natural habitat, as well as the increased pressure of climate change, drove populations into the ground until they were considered extinct in the wild.
About 1,900 of these horses are still alive today, and small numbers are being slowly reintroduced into the wild in Mongolia. Hunting p-horses is now a punishable offense in their native country, and three reintroduction sites have been established in recent decades. Encouragingly, 28 of the 35 foals born to a herd in Mongolia’s Hustai National Park this year survived the critical months of infancy, when young horses are most susceptible to predation. But the horses’ situation remains critical: All living members of this species are descended from 14 individuals captured between 1910 and 1960, raising conservationists’ concerns about low genetic diversity. A lack of heterogeneity in the population lowers the horses’ health, and increases the likelihood of herds being felled by disease or further disturbances to their habitat in the future. As such, scientists remain vigilant about avoiding p-horse inbreeding.
Part of p-horses' Species Survival Plan involves the use of cutting-edge assisted reproduction technology. In particular, an artificial insemination procedure initially tailored for use in the scimitar-horned oryx at SCBI in 2000 has yielded immense success for p-horses. After scientists collect semen from stallions, they insert the sample directly into the mare’s uterus while she is held in place by a hydraulic restraint. Because this procedure is slightly more involved than those for other animals, in which the deposit is made just below the cervix, p-horse mares are also treated with a mild sedative to help calm their nerves. The technique was amended from its initial oryx iteration and first successfully bred a p-horse at SCBI in 2013.
According to Dolores Reed, an animal caretaker at SCBI, it’s been nearly three decades since four of these foals have frolicked together in the fields of SCBI at once. The firstborn this year was a filly named Dahlores, born on March 20, followed by three colts on March 23, April 30 and May 29.
Reed confirms that Dahlores, the oldest foal, was indeed named after her, blending in a touch of the horses’ cultural legacy: “‘Dah’ is something of a surname in Mongolia,” she explains.
Although Reed says the colts have not yet begun to show many distinct personality traits, a few hints of their future temperaments are already emerging—just in time for the three boys to be named. SCBI has launched a small campaign on Twitter, allowing friends of the Smithsonian to vote on the most meaningful monikers using the hashtag #MyLittlePhorse. To inform the decision-making process, SCBI describes the oldest colt as “outgoing and confident”; the second colt as “especially shy”; and the youngest as “indecisive” as he finds his footing in the herd. The names will be chosen from the following list: Citizen Mane; Takhi Twist (in Mongolia, these horses are called “takhi,” or “spirit”); Ulaanbaatar Hero (as an homage to the capital of Mongolia); Steppenhoof; and Gobi Wan Kenobi (both nods to the horses’ native habitat of Gobi Desert steppes). When they come of age, the boys will be sequestered from the herd to avoid potential inbreeding with relatives. In the meantime, however, they appear to be enjoying the company of their fellow horses.
“Everyone is doing well and they’re quite healthy,” says Reed. “I look forward to watching them grow up.”