Science magazine publishes breakthrough research, Slovenian scientists are also involved

A long-term study of birds and bats has revealed that using air currents for flight is the most energy-efficient form of active movement on Earth. Previously, swimming was considered the most efficient method. This discovery, involving Slovenian researchers, highlights the importance of protecting corridors used by large birds, according to the Society for Observation and Study of Birds in Slovenia (DOPPS). The findings were published in Science, one of the world's most prestigious scientific journals. The research, which lasted seventeen years, tracked the movements of 850 individuals from different bird and bat species using tracking devices and radar data. It represents the largest study to date on the energetic costs of long-distance travel among free-living animals. Slovenia contributed through its extensive telemetry monitoring program conducted by DOPPS. The study overturned the previous belief that swimming was the most energy-efficient mode of transport. Earlier studies had suggested this, but they were conducted in controlled laboratory environments. Birds can travel vast distances with extremely low energy expenditure, comparable to their energy consumption during rest. For example, a hawk might flap its wings only 0.1 percent of the time it spends in the air. These birds rely on specific, invisible but clearly defined air current corridors to move over long distances. According to Tomaž Mihelič, a professional director at DOPPS and co-author of the study, these corridors explain why certain species always appear at specific locations. They cannot adapt to flying elsewhere, emphasizing the need to keep these corridors safe. In Slovenia, a significant corridor for large raptors has formed due to the country’s unique geography. It serves as the only route between the Adriatic Sea and the Alps. Due to the Adriatic Sea on one side and the Pannonian Basin on the other, raptors must pass through the Dinaric ridges and the mountainous region stretching from the southern part of Slovenia, including Čičarija and Snežnik, to the Julian Alps. This corridor is crucial both in good weather, when birds find thermal updrafts on slopes, and in bad weather, when they glide along rising wind currents hitting mountain barriers. Mihelič emphasized the importance of protecting this area, noting that threats here could endanger rare bird species across the region. The European Commission decided to co-finance the project Life for lifelines to preserve this corridor.