Greater Noctule Bats: Aerial Predators of Migrating Songbirds

Recent research published in the journal *Science* has revealed that the greater noctule bat (*Nyctalus lasiopterus*), Europe’s largest bat species, actively hunts and consumes migrating songbirds mid-flight. This groundbreaking study, led by researchers from Aarhus University and the Doñana Biological Station in Spain, utilized advanced biologging technology to capture the bat's hunting techniques, marking a significant advancement in understanding the species' predatory behavior.

Caught In Act: Scientists Record How Europe's Largest Bat Catches And Consumes Passerine Bird Mid-airScientific AmericanEurope’s Largest Bat Caught Dining on Birds Mid-FlightScience NewsNew York TimesThe Guardian

The research team equipped 14 greater noctule bats with lightweight biologgers that recorded their altitude, movement, and echolocation sounds. The study documented two notable hunting events, one of which involved a bat pursuing a European robin (*Erithacus rubecula*) from an altitude of approximately 1.2 kilometers (4,000 feet). The bat's pursuit lasted nearly three minutes, during which the robin emitted 21 distress calls before falling silent. Following the kill, the bat continued to chew its prey for 23 minutes while maintaining flight.

Cosmos MagazineThe GuardianEurope’s Largest Bat Caught Dining on Birds Mid-FlightCaught In Act: Scientists Record How Europe's Largest Bat Catches And Consumes Passerine Bird Mid-airScience NewsScientific AmericanNew York Times

Dr. Laura Stidsholt, a co-author of the study, noted, “It’s fascinating that bats are not only able to catch them, but also to kill and eat them while flying.” The researchers hypothesized that the bats bite off the wings of their avian prey to reduce drag, allowing them to consume the rest of the bird mid-air.

New York TimesCaught In Act: Scientists Record How Europe's Largest Bat Catches And Consumes Passerine Bird Mid-airThe GuardianEurope’s Largest Bat Caught Dining on Birds Mid-FlightCosmos MagazineScientific American

The idea that greater noctule bats might prey on birds has been suggested for decades, primarily through indirect evidence such as feathers found in bat droppings. Dr. Carlos Ibáñez, a key figure in this research, has been investigating this behavior since he first observed feathers in bat feces nearly 25 years ago. Despite skepticism from the scientific community, the recent findings provide direct evidence of this predatory behavior.

New York Times

The greater noctule bat is considered one of Europe’s rarest and most endangered species, facing threats from habitat loss due to droughts and wildfires. The study's findings not only enhance our understanding of the bat's diet but also underscore the complex relationships within nocturnal ecosystems. Dr. Elena Tena, another co-author, emphasized that while the predation evokes empathy for the prey, it is a natural part of the ecosystem.

Europe’s Largest Bat Caught Dining on Birds Mid-Flight

While the study has been met with enthusiasm, some researchers express concern over the implications of such predatory behavior on migratory bird populations. However, the authors assert that the findings do not suggest a significant threat to these populations, but rather highlight the adaptability of the greater noctule bat in utilizing available food resources.

Cosmos Magazine

• “We finally figured out the murder mystery,” — Dr. Laura Stidsholt, Aarhus University

New York Times

• “While it evokes empathy for the prey, it is part of nature.” — Dr. Elena Tena, Doñana Biological Station

The Guardian

• “It is a remarkable example of how persistence, patience, and technology can finally illuminate a behavior that has evaded science for generations,” — Dr. Laura Stidsholt

Europe’s Largest Bat Caught Dining on Birds Mid-Flight

The research opens avenues for further studies on the foraging behavior of other bat species and the impact of changing migratory patterns on their diets. The team plans to continue monitoring greater noctule bats to gain deeper insights into their ecological roles and behaviors.

Scientific American

This study not only confirms a long-standing hypothesis but also enhances our understanding of the dynamics within nocturnal ecosystems, revealing the greater noctule bat as a formidable predator in the night sky.

Europe’s Largest Bat Caught Dining on Birds Mid-Flight