Study: Mare Vocalization Associated With Foal Survival

What you might hear if you used an automatic interpreter app in a field full of mares and foals:

“Hey baby, I’m right here if you need anything.”

“Hey Mama! I’m gettin’ hungry!”

“Mommmmmy! Where’d you go?”

As much as horses tend to rely on body language to communicate with each other, a lot of vocal interaction still goes on. Between mares and foals, the purpose of the communication differs depending on who starts the “conversation.” Further, effective mare-foal vocal communication even seems to help foals survive, a new study has revealed.

“Auditory exchanges between mares and foals seems to have both short-term and long-term benefits that ensure that the foal’s needs are met,” said Cassandra M. V. Nuñez, PhD, research assistant professor in the University of Memphis’s Department of Biological Sciences, in Tennessee.

Mares Snorting Softly: ‘Baby, I’m Here.’

Nuñez and her fellow researchers observed 45 mare-foal pairs living in feral herds on the barrier island of Shackleford Banks off the coast of North Carolina. Noting each time a mare or foal initiated communication, they gathered detailed data about vocalizations from more than 3,000 hours of field observation.

They found that mares did a lot of what they called “snorting”—the peaceful nose-blowing sound horses sometimes make while grazing, Nuñez said. Usually when they snorted, the foal was close by, and nothing happened as a result of the snort. “It seems to be a sort of contact call,” she said. “The mare didn’t seem to particularly want anything to happen with that communication. It’s more like, ‘Hey, in case you need me, I’m here.’”

Even so, it seemed purposeful. “More often than not, the foals would respond to the snort with their own snort,” Nuñez said. “It really did seem intentional.”

Study: Mare Vocalization Associated With Foal Survival

What’s more, the researchers noted a direct link between mare-initiated communication—primarily snorts—and foal survival, said Nuñez. During their three-year study, nearly 30% of the foals died within the first year of life. (The team did not investigate reasons for death.) Foals whose dams initiated communication the most during the first 10 weeks of life were more likely to live to 1 year of age than foals whose dams communicated less, she said.

“I think it enables the foals to be more exploratory, allowing them to gain experiences in their social groups and in their environment,” she said. “The mares were essentially saying, ‘Don’t stop what you’re doing, but I’m here,’ and that might have given the foals the confidence or the authorization to go explore and learn.”

While communication trends evolved as the foal grew, that communication didn’t just stop at six months, she added. “In domestic breeding programs, it’s common to artificially wean foals at about six months of age,” she said. “But when we look at how they’re still communicating with each other in free-roaming environments at well beyond that age—and especially that there’s a link to their survival—it certainly raises questions about that breeding practice.”

Foals Knickering, Whinnying: ‘I want something!’

Meanwhile, foals tended to use stronger vocal sounds, including nickers and whinnies, to initiate communication with their dams, said Nuñez. Compared to their mothers’ snorts, the foals’ calls usually occurred from a greater distance. And they usually resulted in something happening—usually shortening that distance, with or without suckling.

“It’s like they suddenly realize, ‘Oh, Mom’s really far,’” she said. “When the foals initiated the communication, it usually wasn’t to keep contact but because they wanted or needed something, like a sense of security or nutrition.”

It’s important to note, however, that the study only looked at the initiation of communication, Nuñez said. “We didn’t look at responses in our data, but they would very often respond to one another,” she explained. “The responses themselves would fill an entirely separate research project.”