The new moon on February 17 marks the beginning of the Lunar New Year, which is celebrated in many Southeast and East Asian countries. According to the Chinese zodiac, it’s also the beginning of the Year of the Horse, which provides a perfect excuse to complain about the science of horses and their animal relatives.
Domestic horses are the best-known members of this species. EquusWhich includes, in addition to three species of donkeys and three species of zebra, a wild relative called Przewalski’s horse. All have their roots in North America, which was home to the oldest known horse relatives up to 55 million years ago. But horses became extinct on the continent at the end of the last ice age; All modern tools come from Africa and Eurasia, where domestication also occurred.
That development changed history for humans and horses alike. Horses carried many civilizations to their heights, but have found themselves as an anachronistic object in modern society. Sue McDonnell, an equine behavior scientist at the School of Veterinary Medicine at the University of Pennsylvania, says scientific investigation of horse behavior is only decades old.
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scientific American To shed light on some of the most interesting science surrounding this year’s star animals, McDonnell spoke with Sarah King, a behavioral ecologist at Colorado State University who specializes in horses and other equines.
read more: The Surprising New History of Horse Domestication
horses are highly social
Domestic horses have three basic needs: freedom, forage, and companionship with other horses. This is because the social nature of these animals is very deep.
Let the horses loose and something remarkable will happen, says McDonnell. “They quickly reintegrate into the social structure that was in place when we first domesticated them,” she says. In that structure, each herd consists of several so-called harems consisting of a stallion and a handful of mares and their offspring, as well as a “bachelor band” of young related males who fend off threats to the herd.
Studies have shown that the horses with the most foals are also those that have friendly relationships with their mares, rather than those that rely on aggression and violence. “The horse community is really held together by affiliated bonds,” says King.
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don’t look down on hooves
For domestic horse owners, hooves are a headache – they are prone to breakage and require regular trimming and shoeing. But those problems only arise because of the hard surfaces that domestic horses have to walk on. “Wild horses don’t have any problems,” says McDonnell.
She explains that the hooves of these horses undergo seasonal changes in response to local climate and surfaces. Horses’ hooves lengthen in the spring and fall, which act “like little skis” to help the animal move on soft ground. In winter and summer, when the ground is hard and animals do not move as much, hooves naturally become shorter.
Mixed landscape of wild equine conservation
Of the wild equine species, King is most concerned about the critically endangered African wild asses (equus africanus), who live around the Horn of Africa. “They’re in a very inhospitable environment – there are real deserts out there – and of course, there are a lot of political issues in that part of the world as well,” she says. The animals are also hunted for food and medicine and have to compete with livestock for fodder food.
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In contrast, their distant cousins, the Przewalski horses of Central Asia, are reemerging after becoming extinct in the wild in the 1960s. After a careful breeding program in zoos, scientists began reintroducing horses into the wild in the 1980s. And now, King says, some populations are completely self-sufficient. “They are a real conservation success story,” she says.
read more: The last wild horses are finally returning to their natural habitat
Horses can literally smell a person’s fear
This won’t surprise anyone who has worked extensively with horses, but research published last month experimentally proves that horses can smell human fear. “Our emotions are central when interacting with horses,” said study author Plotin Jardat, a horse behavior and welfare researcher at France’s National Institute for Agriculture, Food and Environment Research. scientific American In those days.
Better research about precision How McDonnell says the impact of human emotions on a horse’s reactions is important for animal welfare. For example, defensive behavior in a horse can easily be misinterpreted as aggression, she notes, and this can make people fearful—which, new research shows, can put the horse further on edge, resulting in a tricky feedback loop.
read moreHorses can smell your fear, strange study reveals
AI can help owners take care of their horses
Horses have spent millennia evolving to avoid predators, and this has made them loathe to show signs of pain or weakness around humans, McDonnell says. In recent years veterinarians have begun to try to determine whether a horse is sick through video footage. Once the horse is alone, she says, “you can detect a lot of subtle behaviors indicating discomfort.”
But this is not a quick technique. That’s why McDonnell is working with artificial intelligence experts to train a system that can detect tiny signals that veterinarians pick up when sifting through horse footage, but much faster than any human can.
Horses communicate more creatively than you might imagine
If cats meow and ducks quack, horses stereotypically neigh – but they also bleat, croak, snort and yowl, and those noises have, for the most part, been ignored. “We’re beginning to understand that there’s probably a lot of communication going on in those noises,” says King. “Understanding the context and what those noises mean is, I think, really interesting.”
