The 24th annual international bat census at Poland’s Międzyrzecki Rejon Umocniony (MRU) recorded 39,131 bats from 11 species, marking the second-highest total since the survey began in 1999. The most numerous were greater and lesser mouse-eared bats, with 28,500 and 5,800 individuals, respectively. This long-running study highlights MRU as a vital hibernation site for bats across Poland and parts of Germany.
Climate Change and Adaptation
Despite climate shifts, the bat population in MRU remains stable. Notably, cold-adapted species are increasingly hibernating in surface bunkers due to rising temperatures in the underground tunnels. However, scientists caution that human disturbances and drying conditions in the tunnels could jeopardize the bats’ survival.
The MRU system, managed by Poland’s Regional Directorate for Environmental Protection, is a conservation success story. Protected under Natura 2000, the site features over 30 km of tunnels and bunkers, providing an ideal habitat for hibernation. Strict access controls have minimized disturbances, ensuring the bats’ safety.
An International Collaboration
Over 60 researchers from 11 countries participated in the 2024 census, underscoring MRU’s global significance. This unique ecosystem not only supports biodiversity but also serves as a key indicator of climate change impacts.