Because it is loud and carries over a distance, the whinny seems to be a means of seeking social contact with others who are far off or out of view. | Photo: iStock

A: Last week I described the nicker as a quiet, affiliative vocalization. The whinny, or neigh, is a louder, longer call. The whinny is defined in “The Equid Ethogram” by animal behaviorist Sue McDonnell, PhD, as a “loud, prolonged call … beginning high pitched and ending lower pitched. The head is elevated and the mouth slightly opened.”

Because it is loud and carries over a distance, the whinny seems to be a means of seeking social contact with others who are far off or out of view. You’ll hear it between a mare and foal who are separated, between pasture-mates who have been separated, or from a horse that is temporarily separated from visual contact with others, such as a horse on a trailer at a show. It differs from the squeal or scream, two other loud and high-pitched vocalizations, which both tend to be used in the context of more agonistic or aggressive interactions.

There is a little bit of research into how well horses identify specific individuals by their whinny, but it’s not definitive. Some work shows that foals and dams can recognize each other by their whinny. But it’s been suggested that as an adaptive behavior, it may not be that important to be able to recognize a specific individual by his call. If a horse or foal is separated from his band, as long as anyone responds back to his call out, they’ll be able to be rejoined. And it might be more efficient for horses to respond to the call and not worry about discriminating who the caller is. Loud vocalizations might elicit the attention of predators to a horse separated from his band-mates on a wide open grassland