Scientists attached sensor backpacks to two greater noctule bats, recording movement, acceleration, altitude and echolocation. The data revealed a high-altitude, high-speed dive with continuous low-frequency calls, midair removal of the bird's wings to reduce drag, and feeding while flying. With fewer than 10,000 individuals left, these findings both solve a longstanding biological question and offer insights useful for conservation of this threatened species.
Sensors Reveal How Greater Noctule Bats Catch and Kill Songbirds Midair
Scientists attached sensor backpacks to two greater noctule bats, recording movement, acceleration, altitude and echolocation. The data revealed a high-altitude, high-speed dive with continuous low-frequency calls, midair removal of the bird's wings to reduce drag, and feeding while flying. With fewer than 10,000 individuals left, these findings both solve a longstanding biological question and offer insights useful for conservation of this threatened species.
02:32 PM, 11/19/2025Science
Researchers fitted tiny sensor backpacks to two greater noctule bats to record how these nocturnal predators capture songbirds in flight. The lightweight devices logged movement, acceleration, altitude and sounds — including echolocation — and provided the first detailed sensor evidence of a midair strike.
Analysis of the recordings shows a dramatic sequence: the bat drops from high altitude and dives at high speed while emitting continuous low-frequency echolocation calls. Data and movement signatures indicate the bat made contact with its prey, removed the bird's wings while both animals were still airborne to reduce drag, and then began feeding while remaining in flight.
"We know that songbirds perform wild evasive maneuvers such as loops and spirals to escape predators like hawks during the day — and they seem to use the same tactics against bats at night," said Assistant Professor Laura Stidsholt of the Department of Biology at Aarhus University.
Stidsholt described the behaviour as striking: a captured songbird can weigh roughly half as much as the bat itself. She compared it to a person catching and eating a 35-kilogram animal while jogging, illustrating the unusual scale of this predation.
The study highlights how specialized, lightweight monitoring equipment can reveal fine-scale predator–prey interactions and help guide conservation actions. Greater noctules are the largest bats in Europe but have become increasingly rare: populations are estimated at fewer than 10,000 individuals and the species is listed as threatened. Bats provide important ecosystem services, including insect control, and monitoring their behaviour can inform measures to protect both bats and the ecosystems they support.
Scientists had sought direct evidence of greater noctules hunting birds for more than 25 years. The new sensor data confirm long-held suspicions about the bats' tactics and provide a clearer picture of how an endangered predator captures unexpectedly large prey in flight.
"We finally figured out the murder mystery," Stidsholt said. "While it evokes empathy for the prey, it is part of nature," added lead author Elena Tena, who said the team recognized they had recorded something extraordinary and listened to the data several times to fully grasp what was captured.