Behavior Differences by Gender in Young Horses

Studies in dogs and humans have shown that young females are generally more anxious than young males when presented with an unfamiliar experience or setting. Researchers at the Graf Lehndorff Institute for Equine Studies in Germany designed a trial to determine if the same gender difference could be found for horses.

Fifteen Warmblood yearlings (six colts and nine fillies) were used in the study. The young horses had been raised and handled in identical ways. Each day for five days, the horses were brought individually into an arena with a previously unknown human. The person would stand motionless for a few minutes and would then approach the horse, put a halter on it, and attempt to groom the horse and pick up its feet. The horse’s behavior and heart rate were recorded and interpreted as indicators of stress or anxiety.

In this study, fillies explored the surroundings and showed more interest in approaching the motionless person than the colts, which were less eager to explore and more anxious to get back to their group of familiar peers. Initially, the colts also were not as easy to approach and halter, and they were more resistant to having their feet picked up.

In contrast to their behavior, there was little or no difference in heart rate between colts and fillies. Yearlings of both sexes were equal in their ability to get accustomed to people and to be handled.

While each horse showed an individual pattern of stress and anxiety, in general colts were more anxious than fillies in this study of yearling Warmblood horses. Studies with more horses and also with different breeds could show varied results.