Cuando miran a un depredador, los caballos mantienen una cara de póquer mientras sus corazones se aceleran

When eyeing a predator, horses maintain a calm expression even as their heart rates rise, according to a new study conducted by researchers at The Ohio State University. The findings suggest that horses can recognize predators based solely on visual cues, even in controlled conditions devoid of other sensory input such as smell or sound. This ability appears to be linked to their evolutionary history and survival strategies, offering insights into how these animals process threats in complex environments. The study took place in a controlled setting where horses were exposed to different visual stimuli while monitored for physiological responses. Researchers used a combination of video recordings and heart-rate monitors to track the horses’ reactions. Each horse was placed in a standard stall and shown a series of short, silent videos. These included footage of wombats grazing, as well as two types of wolf behavior, aggressive interaction and grooming. The order of presentation varied between individual horses, with some seeing aggressive wolf behavior first and others watching grooming sequences first. During the experiment, handlers remained present but turned away from the screens to avoid influencing the horses’ behavior. The researchers operated the equipment remotely to ensure unbiased observation. Horses wore heart-rate monitors throughout the session, allowing scientists to measure real-time changes in cardiac activity. Video recordings captured the horses’ physical responses, including head movements, tail swishing, and overall body language. The results revealed that horses exhibited a notable increase in heart rate when viewing images of wolves, regardless of whether the wolves were engaging in aggressive or non-aggressive behaviors. This response occurred even when the horses did not display outward signs of distress, such as head bobbing or tail movement. Instead, they maintained a neutral posture, suggesting a level of cognitive restraint in their evaluation of potential threats. Lead author Zeynep Benderlioglu, a senior lecturer in evolution, ecology, and organismal biology at Ohio State, noted that this behavior reflects a sophisticated ability to assess danger without immediate flight or fight responses. “They’re not in fight-or-flight mode,” she explained. “But they’re assessing, and they’re doing it in a remarkably fast way. Their hearts are racing at the same time.” The study also found variations in how different horses responded to the stimuli. Male horses and those with higher social status within their herds showed more pronounced increases in heart rate. This could be related to their roles in group dynamics, where leadership and vigilance might be more critical. Social status and temperament factors, such as social anxiety or fearfulness, were also considered in the analysis of behavioral patterns. The implications of the study extend beyond academic interest. Understanding how horses react internally to perceived threats can help improve their care and management. Riders and handlers may not always detect subtle signs of agitation, which could affect both the horse’s well-being and the safety of those working with them. The research underscores the importance of recognizing internal states that may not manifest in visible behavior. This work, published in the journal PLOS ONE on July 15, 2026, marks a significant step in understanding equine cognition and emotional processing. By isolating visual cues from other sensory inputs, the study provides a novel method for exploring how animals interpret their environment. Future research may build on these findings to further explore the interplay between perception, emotion, and behavior in domesticated species.