Scientists Crack the Secret Behind Horses' Musical Neigh

Scientists just solved a mystery that's been puzzling them for years: how horses create that distinctive high-low whinny sound that rings out across pastures and barns.

Researchers at the University of Copenhagen made an unexpected discovery. Horses don't just vocalize when they whinny. They whistle too.

The team used tiny cameras inserted through horses' noses to film what happens inside while the animals made sounds. They also studied detailed scans and tested the voice boxes of deceased horses to understand the mechanics.

What they found changes everything we thought we knew about horse communication. While the low-pitched grunt comes from air vibrating tissue bands in the voice box (similar to human speech), the high-pitched squeal is actually a whistle starting in the same spot.

The whistling happens when an area just above the voice box contracts during vocalization, leaving a small opening for air to escape. It's completely different from how humans whistle with our mouths.

This makes horses the first known large mammal capable of whistling through their voice box. Even more remarkable, they're the only animal that can whistle and vocalize simultaneously, creating that signature two-toned sound.

A few small rodents like rats and mice can whistle this way, but nothing the size of a horse. Wild Przewalski's horses and elks have similar abilities, but more distant relatives like donkeys and zebras cannot make these high-pitched sounds.

Why This Inspires

The discovery reveals horses may be more sophisticated communicators than we realized. Being able to produce two different pitches at once could help them express complex emotions and messages simultaneously.

Lead researcher Elodie Mandel-Briefer believes horses use these two sound dimensions to convey richer feelings when socializing with each other. A greeting might sound different from a celebration at feeding time, even if both are whinnies.

Jenifer Nadeau, a horse researcher at the University of Connecticut who wasn't involved in the study, had an immediate reaction to the findings. "I'd never imagined that there was a whistling component. It's really interesting, and I can hear that now," she said.

The research opens new questions about how this unique ability evolved and what horses are really telling each other with their distinctive calls.

Every whinny across every pasture now holds new meaning.