Scientists discover world's oldest Brandt's bat in Estonian cave

Researchers at the University of Tartu discovered the world's oldest known Brandt's bat while conducting a winter survey in the Piusa caves in Estonia.

The team identified the animal by a band placed on it during a study in the early 1990s. This find also represents the second-oldest bat ever recorded in Europe across all species. Oliver Kalda, a junior research fellow at the University of Tartu, explained that the discovery occurred during a survey for the Estonian Environment Agency.

The agency commissioned the study to monitor population changes at various hibernation sites. Because the bat was alone in the cave, the researchers were able to see its identification band clearly in a flashlight beam. The bat is at least 36 years and seven months old, surpassing the previous world record of 32 years for its species.

While many small rodents of similar size live only a few years, bats have evolved mechanisms that allow them to live exceptionally long lives. Scientists use these animals as model species to study how genetics and physiology contribute to longevity in small mammals. The Piusa cave system is one of the largest hibernation sites in Northern Europe, hosting more than 4,200 bats last winter. The record-breaking bat has been observed at this site at least four times over several decades.

To protect these animals, the Estonian government restricts public access to several underground sites from September 1 to May 1 to prevent bats from waking up and depleting their energy reserves.