Oct 10, 2025 06:03 PM
(This post was last modified: Oct 10, 2025 06:04 PM by C C.)
https://www.eurekalert.org/news-releases/1101017
INTRO: After nearly 25 years of research, the mystery has finally been solved: Europe’s largest bat doesn’t just eat small birds – it hunts and captures them more than a kilometre above the ground. And it eats them without landing.
An international team of researchers has shed light on how Europe’s largest bat hunts and consumes small birds. The results, now published in Science, make for fascinating reading – a story of nocturnal aerial acrobatics, pursuit and predation.
Every year, billions of songbirds migrate between their breeding grounds and wintering areas. Many species fly high and travel at night, partly to avoid daytime predators. But that doesn’t make the journey risk-free – bats hunt at night.
Riding on the bats’ backs. Researchers have virtually hitched a ride on the back of Europe’s largest bat species – the greater noctule (Nyctalus lasiopterus) – by equipping them with tiny “backpacks” containing biologgers developed at Aarhus University. These instruments record the bats’ movements, acceleration, altitude, and sounds (including the bat’s echolocation calls), revealing their hunting techniques as they pursue prey more than one kilometre above the ground in total darkness.
The new study shows that these bats can fly high into the night sky to locate and attack unsuspecting birds. Unlike certain insects, birds cannot hear the bats’ echolocation calls and may only realise the danger at the very last moment, giving them little chance to escape.
The bats’ ability to detect birds at such distances is due to their loud and relatively low-frequency ultrasound echolocation calls. And once they are close enough to select their target, they attack – signalled by a rapid burst of short echolocation calls.
Daring dives. Data from the biologgers show that the bats pursued their prey in steep, breakneck-speed dives towards the ground, much like fighter aircrafts in dogfights.
They plunged vertically for 30 and 176 seconds respectively, beating their wings faster and harder and tripling their acceleration while emitting continuous attack calls. The bat that dived for 30 seconds eventually gave up – birds are at least as agile in the air as bats.
Twenty-three minutes of chewing. The second bat, however, caught its prey close to the ground after nearly three minutes of pursuit. The microphone recorded 21 distress calls from the bird (a robin), followed by 23 minutes of chewing sounds from the bat as it flew at low altitude.
Combined with X-ray and DNA analyses of songbird wings found under the bats’ hunting grounds, the data from just two bats paint a clear picture of the final act:
The bats kill the birds by biting them, then bite off their wings – probably to reduce weight and drag. The researchers believe that the bats then stretch the membrane between their hind legs forward like a pouch and eat the bird mid-flight.
Wild manoeuvres. “We know that songbirds perform wild evasive manoeuvres 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. It’s fascinating that bats are not only able to catch them, but also to kill and eat them while flying. A bird like that weighs about half as much as the bat itself – it would be like me catching and eating a 35-kilo animal while jogging,” says Assistant Professor Laura Stidsholt from the Department of Biology at Aarhus University.
She is one of the study’s lead authors and has for several years refined and applied biologger technology in her bat research, leading to numerous scientific papers – and surprises. At the time when she finalized the data collection and did the analysis for this paper, Stidsholt was a Postdoc at the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) in Berlin... (MORE - details, no ads)
INTRO: After nearly 25 years of research, the mystery has finally been solved: Europe’s largest bat doesn’t just eat small birds – it hunts and captures them more than a kilometre above the ground. And it eats them without landing.
An international team of researchers has shed light on how Europe’s largest bat hunts and consumes small birds. The results, now published in Science, make for fascinating reading – a story of nocturnal aerial acrobatics, pursuit and predation.
Every year, billions of songbirds migrate between their breeding grounds and wintering areas. Many species fly high and travel at night, partly to avoid daytime predators. But that doesn’t make the journey risk-free – bats hunt at night.
Riding on the bats’ backs. Researchers have virtually hitched a ride on the back of Europe’s largest bat species – the greater noctule (Nyctalus lasiopterus) – by equipping them with tiny “backpacks” containing biologgers developed at Aarhus University. These instruments record the bats’ movements, acceleration, altitude, and sounds (including the bat’s echolocation calls), revealing their hunting techniques as they pursue prey more than one kilometre above the ground in total darkness.
The new study shows that these bats can fly high into the night sky to locate and attack unsuspecting birds. Unlike certain insects, birds cannot hear the bats’ echolocation calls and may only realise the danger at the very last moment, giving them little chance to escape.
The bats’ ability to detect birds at such distances is due to their loud and relatively low-frequency ultrasound echolocation calls. And once they are close enough to select their target, they attack – signalled by a rapid burst of short echolocation calls.
Daring dives. Data from the biologgers show that the bats pursued their prey in steep, breakneck-speed dives towards the ground, much like fighter aircrafts in dogfights.
They plunged vertically for 30 and 176 seconds respectively, beating their wings faster and harder and tripling their acceleration while emitting continuous attack calls. The bat that dived for 30 seconds eventually gave up – birds are at least as agile in the air as bats.
Twenty-three minutes of chewing. The second bat, however, caught its prey close to the ground after nearly three minutes of pursuit. The microphone recorded 21 distress calls from the bird (a robin), followed by 23 minutes of chewing sounds from the bat as it flew at low altitude.
Combined with X-ray and DNA analyses of songbird wings found under the bats’ hunting grounds, the data from just two bats paint a clear picture of the final act:
The bats kill the birds by biting them, then bite off their wings – probably to reduce weight and drag. The researchers believe that the bats then stretch the membrane between their hind legs forward like a pouch and eat the bird mid-flight.
Wild manoeuvres. “We know that songbirds perform wild evasive manoeuvres 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. It’s fascinating that bats are not only able to catch them, but also to kill and eat them while flying. A bird like that weighs about half as much as the bat itself – it would be like me catching and eating a 35-kilo animal while jogging,” says Assistant Professor Laura Stidsholt from the Department of Biology at Aarhus University.
She is one of the study’s lead authors and has for several years refined and applied biologger technology in her bat research, leading to numerous scientific papers – and surprises. At the time when she finalized the data collection and did the analysis for this paper, Stidsholt was a Postdoc at the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) in Berlin... (MORE - details, no ads)
