Who's the Herd Leader? It Depends, Researchers Say

Who’s the leader of the pack? Or in the case of horses, the herd? If you think it’s the dominant horse, think again. French researchers recently determined that the dominant horse is rarely the one who makes the first move to get the herd going. And, in fact, the “herd leader” often changes throughout the day.

“To really be a true leader, you need followers, and that’s true of horses as well as humans,” said Odile Petit, PhD, of the University of Strasbourg, in Alsace, France. Petit presented her work on herd movements at the 2015 Equine Ethology Day held April 9 in Saumur, France.

Many researchers and owners have traditionally believed dominant horses—especially stallions or older, dominant mares—to be the herd leaders. But Petit’s research results show that, actually, they often leave the leading up to others. And the ones that most frequently take the job are the most sociable horses, she said.

But, Petit said, neither the dominant horses nor the more sociable horses are most likely to be followed. It’s the ones with the most “friends,” she said.

“It seems to come down to the close relationships that the leading horse has with other horses,” Petit said. “When horses see their ‘friends’ start to move, they’ll often join in and start moving as well.” The horses typically begin to move in small groups until the entire herd is moving.

Petit’s research team studied several herds of about 15 to 20 horses in seminatural settings in very large pastures. They videoed the herds’ movements, starting from well before the movement until after the movement was completed. They found that leaders often gave subtle physical cues—such as specific postures—prior to movement, and these were sufficient to get the horses all moving at approximately the same time. They also noted that nearly every horse in the herd was the leader for at least one movement over the course of a week. However, not all leading horses were followed, in which cases the leader abandoned the movement.

Petit said the team also found, somewhat surprisingly, that a stallion in a group of mares actually appears to disrupt the harmony of the movements. “When we took the stallion out, the mares seemed much more in phase without him,” she said. “And when he was there, he was out of phase with them. If he tried to initiate movements, he usually wasn’t followed.”

Horse herds’ highly complex social structures allow the members to have very efficient and organized group movements, said Petit. “This is vital for a prey group,” she said. “The group has to be able to move from a food point to a water point, for example, without its members getting widely dispersed.”

She also said her team confirmed that social relationships are critical to herd movement. Even when a horse saw a leader begin to depart, whether he followed was typically based on the decisions made by his closest neighbors, “which were generally also its preferred partners,” she said.