Andean Bears Surprise Scientists with Complex Vocalizations During Mating Rituals

Long thought to be nearly mute, the Andean bear—South America’s only bear species—has surprised scientists with its vocal expressiveness during mating. Recognizable by the light markings on its face, this elusive animal was previously known to emit only rare sounds, typically between mothers and cubs in captivity. However, recent footage from camera traps in the Andes has revealed that the bears are far more vocal, producing moans, growls, and purrs in intimate moments.

Between 2020 and 2021, researchers set up camera traps across the Colombian and Bolivian Andes. Their goal was to observe the secretive Andean bear in its natural habitat. To their surprise, the cameras recorded a rich variety of sounds: rhythmic hums, gasps, grunts, and more. These sounds were not random—they formed a consistent part of the bears’ mating rituals. This contradicts past scientific literature, which described the species as largely silent.

Five Distinct Vocalizations Identified in Andean Bears During Mating and Communication Studies

The researchers identified five distinct vocalizations, each with a clear social function. One sound, dubbed “the bite,” is a brief squeal made by females during neck biting—a common part of bear mating behavior. Another, the “humm,” resembles a purr and is the most common vocalization between males and females. These sounds were recorded during long copulation sessions, lasting up to an hour, suggesting a complex and consistent pattern of communication.

The audio recordings were analyzed in detail by Adriana Reyes, one of the study’s lead authors, using spectrograms to transform the sounds into data. Her work enabled the team to move beyond anecdotal observations and establish a scientifically verified vocal profile for the species. This approach marked a significant advancement in studying bear communication, setting a precedent for future acoustic research in the wild.

Andean Bears’ Stealthy Nature and New Discoveries on Bear Communication Across Species

Despite their size, Andean bears are incredibly stealthy, often hiding in treetops and remaining silent in the presence of humans. This makes them difficult to study directly. Their shy nature may explain why such vocalizations were undocumented until now. Scientists also theorize that the bears may adjust their behavior to avoid detection by humans—possibly reducing vocal output when people are nearby.

The findings not only challenge long-standing beliefs about Andean bears but also open new avenues for research into bear communication. They prompt questions about whether different populations of bears have regional dialects and how vocal behaviors vary between species. With polar bears being mostly quiet and black bears typically more vocal, this study highlights the ways in which different bear species may tailor their communication strategies to suit their environments. Ultimately, these insights deepen our understanding of a majestic and elusive creature.