Bats Hunt and Devour Birds Midair: Unveiling Nighttime Predation Drama in European Skies

Bats Eat Birds on the Wing: A Stunning Revelation in Nocturnal Predation

In the silent, star-streaked skies above Europe, a remarkable and almost cinematic predator-prey drama unfolds each autumn. While most of us imagine bats as tiny insectivores flitting through the night in pursuit of moths and mosquitoes, recent research has unveiled a far more audacious behavior: some bats actively hunt, kill, and eat birds in midair, high above the ground[3][5][9][12][16]. This discovery reshapes our understanding of both bats and the peril faced by migratory songbirds during their epic nocturnal journeys.

The Predator: Greater Noctule Bat

The central actor in this drama is the greater noctule bat (Nyctalus lasiopterus), Europe’s largest bat and one of the only three known bat species capable of preying on birds in flight[9][12][16]. With a wingspan reaching 45 centimeters and a weight that can rival its avian prey, the greater noctule is a formidable aerial hunter.

Nighttime Migration: A High-Risk Journey

Billions of small songbirds, such as robins and warblers, undertake long-distance migrations each year, flying at night to avoid daytime predators and overheating[9][12]. For decades, scientists believed these nocturnal flights offered birds relative safety. Yet, the discovery that bats can strike at these heights—sometimes over a kilometer above ground—reveals a previously hidden danger[3][12][13].

How Bats Hunt Birds in Midair

The Hunt

Armed with advanced biologging technology—tiny “backpacks” with sensors and microphones—researchers have tracked greater noctules in real time[3][12][15]. These devices recorded bats soaring hundreds of meters high, searching for prey using echolocation. Their calls are pitched low enough that birds cannot detect them, giving the bats a stealth advantage[5][9].

When a bat locks onto a target, it initiates a rapid, high-speed dive, reminiscent of a fighter jet in a dogfight[5][15]. In some chases, bats pursued birds for up to three minutes, maneuvering with breathtaking agility through the night sky[3][15]. Songbirds, for their part, try to evade with wild loops and spirals—a testament to the evolutionary arms race between predator and prey[15].

The Kill

Once within striking distance, the bat attacks with a burst of short, intense echolocation calls. Audio from biologgers has captured the distress calls of birds as they are caught—21 cries in one recorded case—followed by the telltale sound of chewing as the bat eats its meal while still airborne[3][5][12][15].

Eating on the Wing

After subduing its prey, the greater noctule bites through vital areas to kill the bird, then removes its wings—a maneuver thought to reduce drag and make the prey easier to handle in flight[5][9][12][15]. The bat uses the membrane between its hind legs as a pouch, holding the bird and consuming it midair, sometimes for over 20 minutes without landing[3][5][12][15].

This remarkable feat is even more astonishing considering the prey’s size: a typical songbird can weigh half as much as the bat itself. As Assistant Professor Laura Stidsholt of Aarhus University notes, “It would be like me catching and eating a 35-kilo animal while jogging”[3][12][15].

Evidence Beyond the Hunt

The proof of this behavior goes beyond audio and tracking data. Beneath the bats’ roosts, researchers have found scattered bird wings and DNA evidence linking them to migratory passerines such as robins and warblers[12][15]. X-ray analysis of these remains reveals distinctive bite marks, confirming the identity of the predator[9][15].

Prior to these direct observations, scientists had only indirect evidence—bird feathers and bone fragments in bat droppings or roosts[3][12]. The new biologging studies, however, provide the first real-time evidence of midair bird predation.

Why Hunt Birds?

Most bats feed on insects, but migrating birds represent a massive and underexploited food resource, especially during the migration peaks when billions cross the night sky[9][12]. Only a few fast-flying, echolocating bat species have evolved the necessary tools—speed, power, and specialized echolocation—to exploit this opportunity[9].

Ecological Implications

This newly documented hunting behavior changes our view of aerial food webs and highlights the unseen threats facing migratory birds[12][13]. It also underscores the remarkable adaptability and predatory versatility of bats. The discovery may have implications for conservation, as it reveals the complex—and sometimes perilous—interactions that shape the lives of both bats and birds during migration.

A Window into Evolutionary Arms Races

The aerial battles between bats and birds during migration echo the evolutionary arms races seen between hawks and songbirds by day. Migratory birds, though adept at evasive maneuvers, now must contend with dangers in both sunlit and moonlit skies[15].

As technology allows us to track these elusive predators in their natural element, we discover just how dynamic, dangerous, and awe-inspiring the night sky can be. The greater noctule’s ability to pluck birds from the sky and eat them on the wing stands as one of nature’s most astonishing predatory achievements—a reminder that the darkness above still holds many secrets, waiting to be revealed[3][5][9][12][15][16].

Original source: Ars Technica – Bats eat the birds they pluck from the sky while on the wing