It was always thought that the leader of a herd of horses was the most dominant mare, the alpha mare. But French researchers have recently determined that the most dominant horse is rarely the one who takes the first steps to get the herd going. The ‘herd leader’ would even change during the day.
“To be a true leader, you need followers and that goes for both horses and humans,” said Odile Petit, PhD, from the University of Strasbourg in Alsace, France. Petit presented her work on herd movements at Equine Ethology Day 2015, held April 9 in Saumur, France.
Many researchers and horse owners believed that dominant horses, especially stallions or older dominant mares, were the leaders of a herd. But the results of Petit’s research show that these horses leave the lead to others. And the horses most often taking on this leadership role are the most social horses, she said. But it’s not the dominant or social horses that are most likely to be followed by the herd, Petit said. It are the horses with the most ‘friends’. “It seems that it comes down to the close relationship the lead horse has with the other horses,” said Petit. “When horses see their ‘friends’ get moving, they will often join in and get moving too.” Typically, the horses begin to move in small groups until the entire herd is in motion.
Petit’s research team has examined several herds in semi-natural conditions. Each herd consisted of about 15 to 20 horses and they were in very large pastures. They filmed the movements of the herds, starting to film well before the herd started and then stopped once the movement was complete. They saw that the leader often gave subtle body signals, such as specific postures, before the movement was started. These cues were enough to get the entire herd moving at about the same time. They also saw that almost every horse in the herd took charge of a movement at least once a week. However, not all leading horses were actually followed, which caused the leader to stop the movement in those cases.
Petit said that, surprisingly, the team also found that one stallion in a group of mares actually disturbed the harmony of the movements somewhat. “When we took the stallion out of the herd, the mares seemed to move much more in synch (synchronised) without him,” she said. And when he was there, he was out of sync with them. When he tried to initiate a movement, he was often not followed.”
The highly complex social structures in a horse herd allow the herd members to have a very efficient and organized group movement, Petit said. “This is essential for a prey group. For example, the group must be able to move from a feeding spot to a water spot without all the herd members scattering widely.” She also said her team confirmed that social relationships are crucial to herd movements. Even when a horse saw a leader begin to leave, his choice of whether or not to follow the leader depended on the decisions his nearest neighbours made. “These were generally his preferred partners, too,” she said.
Whether there is an alpha mare at all, as the researchers claim, is debatable. The moment there is an alpha mare in a herd, this does not necessarily mean that she determines every activity of the group. As the researchers also show, it could be that another horse starts an activity and the rest of the group follows. This could possibly just be done under the guidance of an alpha mare.