High up in the misty folds of the Andes, a shaggy-coated bear moves through the trees with quiet grace. With cream-coloured markings tracing around its eyes—like nature’s own glasses—the “Andean bear”, or “spectacled bear” (Tremarctos ornatus), carries with it an air of mystery. It is South America’s only bear species, yet we still know surprisingly little about it.
But the silence surrounding the Andean bear is finally being broken—and it’s the bears themselves who are doing the talking. Recently, scientists tuned into the bears’ secretive world (literally!). In a groundbreaking study, researchers from a coalition of institutions—including the Alexander von Humboldt Biological Resources Research Institute in Villa de Leyva, Fundación Wii in Bogotá, local conservation authorities in Huila and Cundinamarca, and the Wildlife Conservation Research Unit at the University of Oxford—managed to capture the first acoustic recordings of Andean bear mating behaviour in the wild.
But, just as we start to understand them, their home is shifting beneath their feet.
The Andean bears’ lives depend on high-altitude habitats like cloud forests and páramos (the grassy, boggy ecosystems that sit above the treeline and below the glaciers). These ecosystems are incredibly sensitive to temperature shifts. Research led by scientists from Stockholm University and Universidad del Rosario in Bogotá, as well as collaborative work funded by the World Bank and the Spanish Agency for International Cooperation, shows that as the planet warms, high-Andean ecosystems like the páramos are migrating upslope in search of cooler conditions. Yet their movement has limits—eventually, the peaks of the Andes leave no more room for uphill retreat, increasing the risk of what’s known as “habitat compression”. This means habitats are shrinking, reducing space for species like the Andean bear.
This story isn’t new. Palaeoecological records, such as fossilised pollen grains preserved in sediments, show that during cooler glacial periods, páramos expanded downslope, covering broader areas. But in warmer interglacial periods, they shrivelled and retreated upslope, becoming more fragmented. Today’s human-driven warming mirrors that ancient pattern—but it’s happening far faster, leaving these ecosystems with little time to adapt.
This accelerated shift puts the Andean bear in a precarious position. On top of climate pressures, the species already faces mounting threats from habitat destruction and conflict with humans. In parts of Colombia, Peru, and Ecuador, bears are sometimes seen as livestock raiders or crop pests, which can lead to retaliation from farmers. Yet these animals play a crucial ecological role—dispersing seeds, supporting forest regeneration, and keeping ecosystems in balance.They are both symbols and sentinels; ambassadors of fragile landscapes that are rapidly changing.
Now more than ever, we need to listen closely, not just to the soft vocalisations exchanged when they communicate, but to what the bears’ struggle is telling us. In the rustle of branches and the low hush of disappearing high-Andean ecosystems, the Spectacled bear is whispering a warning. It’s up to us to hear it—and respond before their voice fades from the mountains.
Written by Andrés Acosta
MSc. Biodiversity, Wildlife & Ecosystem Health Student
Deanery of Biomedical Sciences
University of Edinburgh
Scotland, UK
Email: A.Acosta-Calderon@sms.ed.ac.uk
Article edited by Eleanor Stamp, a Neuroscience PhD student at the Institute of Genetics and Cancer, University of Edinburgh, and an Online News Editor for EUSci.
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Photo credits: https://animalia.bio/spectacled-bear – Author: Steve Wilson/ Creative Commons licenses
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