Europe's Largest Bat Proven to Hunt and Devour Songbirds Mid-Air, Solving 25-Year Mystery

After decades of speculation, an international team of scientists has definitively proven that Europe's largest bat, the greater noctule, actively hunts and consumes small songbirds while flying more than a kilometer above the ground. This groundbreaking discovery, reported by sciencedaily on November 2, 2025, confirms a long-held hypothesis about the nocturnal predator's diet.

The elusive behavior of the greater noctule (Nyctalus lasiopterus) was finally unveiled through the innovative use of tiny biologgers. These miniature devices, attached to the bats, recorded astonishing aerial dives and distinct mid-flight chewing sounds, providing irrefutable evidence of bird predation, as detailed by Aarhus University researchers.

This revelation resolves a 25-year-old scientific enigma, overcoming previous skepticism within the research community regarding the bat's ability to capture and eat birds mid-flight. The findings, published in the journal Science, paint a vivid picture of high-stakes nocturnal chases in complete darkness, according to scitechdaily.

Researchers, including Laura Stidsholt from Aarhus University and Carlos Ibáñez from Doñana Biological Station, utilized advanced biologger technology to track the bats' movements and acoustic signatures. This allowed them to effectively "ride along" with the bats, observing their hunting strategies at extreme altitudes, Science News Explores reported on October 29, 2025.

The study revealed that these formidable bats execute steep, high-speed dives, akin to fighter jets, to ambush unsuspecting birds. They then kill their prey with a bite, remove the wings to reduce drag, and use a membrane between their hind legs as a pouch to consume the bird while still airborne, as described by The Guardian on October 9, 2025.

This remarkable predatory behavior occurs primarily during bird migration periods, when songbirds travel at night and high altitudes to avoid daytime predators. The greater noctule's unique echolocation, which operates at frequencies beyond birds' hearing range, gives it a significant advantage in these aerial encounters, according to wikipedia.

• The mystery surrounding the greater noctule's diet began nearly 25 years ago when Spanish bat expert Carlos Ibáñez first discovered bird feathers in the droppings of these bats. This initial evidence, though compelling, faced considerable skepticism from the scientific community, which questioned how a bat could successfully hunt and consume birds, some weighing up to half the bat's own mass, in mid-flight.

• The breakthrough came with the deployment of advanced biologgers, miniature "backpacks" developed at Aarhus University. These devices were equipped with multiple sensors, including accelerometers for 3-D movement, magnetometers for direction, altimeters for altitude, and microphones to capture echolocation calls, bird distress calls, and chewing sounds, as detailed by Science News on October 9, 2025.

• The greater noctule bat (Nyctalus lasiopterus) is Europe's largest bat, with a wingspan up to 46 centimeters, and is uniquely adapted for open-air hunting. Its specialized wing morphology allows for fast flight in open areas, while its echolocation calls, at frequencies above the auditory range of birds, enable it to approach prey undetected, according to wikipedia.

• Ecologically, this discovery highlights a previously unappreciated predator-prey dynamic, particularly impacting nocturnally migrating songbirds. While the greater noctule also consumes insects, bird predation can constitute over 80% of its diet during peak migration seasons, demonstrating an opportunistic foraging strategy that capitalizes on abundant food resources.

• Previous attempts to observe this behavior were hampered by the bats' nocturnal habits and high-altitude hunting, making direct visual confirmation impossible. Researchers had tried various methods, including surveillance cameras, military radar, and ultrasound recorders on hot-air balloons, but lacked the direct, on-board data provided by the new biologger technology.

• The study's most compelling evidence included a recorded successful hunt of a European robin, where biologgers captured 21 distress calls from the bird, followed by 23 minutes of continuous chewing sounds from the bat. This audio, combined with X-ray and DNA analysis of bird wings found beneath hunting grounds, provided a clear and grisly account of the mid-air predation, The Guardian reported.

• Understanding the greater noctule's hunting behavior is crucial for its conservation, as the species is listed as "vulnerable" on the IUCN Red List due to habitat loss and disturbance. This research provides vital insights into the ecological role of this least-studied European bat, informing future conservation strategies and further research into its complex life.