When it comes to the complexity of their vocal range, horses have more in common with singing birds than other mammals.
Domestic horses are social animals that prefer to live in herds, and they disseminate information over long distances by whinnying, which research suggests can convey information about the caller’s identity, sex, and body size. Whinnying also allows horses to communicate the nature and strength of their emotional states using two different frequencies, according to a new study in the journal Scientific Reports.
via Mental Floss
