The family Equidae, which includes all modern horses, zebras, and asses, represents a group of mammals with a long evolutionary history, but their current conservation status varies dramatically across species. People often ask whether horses are endangered, a question that requires distinguishing between the globally abundant domestic species and their wild relatives. Understanding the conservation status of equids involves looking beyond the common image of the horse to assess the true wild populations across the planet. The International Union for Conservation of Nature (IUCN) Red List provides a scientific assessment for these species, highlighting which ones face a significant risk of extinction. While the domesticated horse is secure, many of the world’s wild equids are in serious peril.
Clarifying the Term “Horse”: Domestic Versus Wild
The most common source of confusion regarding the conservation status of horses lies in the distinction between the domestic horse, Equus caballus, and truly wild species. Domestic horses, of which there are hundreds of millions worldwide, are not considered to be at risk of extinction and hold no special conservation status. This species is classified as secure due to its immense global population.
Furthermore, many populations often referred to as “wild horses,” such as the American Mustang or the Australian Brumby, are actually considered feral. These are descendants of previously domesticated animals that returned to a free-roaming state, not genetically distinct wild species. Conservation efforts for these feral populations often focus on management due to their abundance, rather than protection from extinction. To find a truly wild horse, conservationists must focus on species that evolved without human intervention.
The Conservation Status of Przewalski’s Horse
The sole surviving species of a truly wild horse is Przewalski’s Horse (Equus ferus przewalskii), which possesses a unique history of near-total loss and subsequent re-establishment. This wild equid, known as the takhi in its native Mongolia, was last observed in its natural habitat in the late 1960s, leading to its declaration as Extinct in the Wild. The entire current population is descended from a small number of individuals captured in the early 20th century, highlighting a severe genetic bottleneck.
Captive breeding programs in zoos and specialized reserves successfully preserved the species’ lineage. Starting in the 1990s, reintroduction projects began returning these horses to their ancestral steppes in Mongolia and China. This conservation success story led to the species’ status being upgraded on the IUCN Red List from Extinct in the Wild to Critically Endangered in 1996, and later to Endangered in 2011.
Today, there are approximately 2,500 Przewalski’s Horses globally, with over 1,300 of them now roaming free in semi-wild and reintroduction sites. The species remains classified as Endangered due to the small size of the wild populations and their limited genetic diversity. Continued monitoring is necessary to ensure the long-term viability of the reintroduced herds in their Asian homelands.
Status of Other Wild Equids: Zebras and Asses
The conservation outlook for the other wild members of the Equus genus—the zebras and asses—presents a mixed but generally concerning picture. Among the zebras, the Grévy’s Zebra (Equus grevyi) is listed as Endangered, having experienced a dramatic population decline of over 80% since the late 1970s. This species, which is the largest of the wild equids, is now found only in small, fragmented populations in parts of Kenya and Ethiopia, with a total wild population estimated at around 3,000 individuals.
In contrast, the Plains Zebra (Equus quagga), which is the most numerous of the zebra species, is listed as Near Threatened, with a total population exceeding 500,000. While this species is widespread, its population is declining in over half of its range countries, indicating that its status is not entirely secure. The Plains Zebra is also notable for the Quagga subspecies, which was hunted to extinction by 1883.
The wild asses of Africa and Asia are facing severe threats within the equid family. The African Wild Ass (Equus africanus), ancestor of the domestic donkey, is listed as Critically Endangered, with fewer than 200 mature individuals left in the wild. This species, which includes the Somali Wild Ass subspecies, has one of the lowest population numbers of any large mammal in Africa.
The Asian wild ass species, or onagers (Equus hemionus), are listed as Near Threatened overall, though their subspecies have varying statuses. The Kiang (Equus kiang), or Tibetan Wild Ass, is the largest of the wild asses and is listed as Least Concern, with a stable population of over 60,000 across the Tibetan Plateau. However, the Persian Onager subspecies is designated as Critically Endangered, with only a few hundred individuals surviving in Iran.
Primary Drivers of Decline in Wild Equids
The decline across many wild equid populations is largely attributed to the expansion of human activities into their native habitats. Loss of range due to agricultural development and the construction of infrastructure fragments the remaining populations, making it difficult for them to access essential resources. This habitat fragmentation isolates groups, which can lead to reduced genetic diversity and increased vulnerability to localized threats.
A threat comes from direct competition with domestic livestock, particularly cattle and goats, for limited grazing land and water sources. In arid environments, this competition forces wild species into increasingly marginal areas. The presence of domestic animals also facilitates the spread of infectious diseases, such as anthrax, to which wild equids often have no natural immunity.
Illegal hunting and poaching continue to pose a risk to several species, often driven by demand for meat and traditional medicine. Additionally, hybridization with domestic donkeys, particularly in the case of the African Wild Ass, introduces non-wild genes into the already small remaining wild gene pool. This genetic dilution compromises their long-term survival.