Listen to honey bees shriek a warning to their hive when murder hornets approach
Scientists have compared the calls, named ‘antipredator pipes’, to fear screams and panic calls
Bees have developed their own version of a fire alarm to warn their hive of predatory murder hornets, a new study has found.
Once they’ve spotted a lurking giant or murder hornet, Asian honey worker bees will immediately string along series of panic calls — termed as “antipredator pipes” — which harsher and more irregular in their frequency.
Giant hornets or even Asian hornets which are closely related to the murder hornets recently discovered in North America are known to prey on bees and often send out scouting insects to search for hives to prey on. On finding one, the scout then returns to inform its nest, which then track the hive and often slaughter the entire colony.
“Antipredator pipes share acoustic traits with alarm shrieks, fear screams and panic calls of primates, birds and meerkats”, the study explains.
These pipes, scientists explain in their study published on Wednesday in the Royal Society Open Science journal, are actually vibroacoustic signals made by raising their abdomens, buzzing their wings and flying about “frantically.”
“These sophisticated defences require timely predator detection and swift activation of a defending workforce,” the authors wrote in the study
“Vibroacoustic signals likely play an important role in organizing these responses because they are transmitted quickly between senders and receivers within nests.”
Lead researcher Heather Mattila, professor of biological sciences at Wellesley College, Massachusetts and her team studied interactions between giant hornets and Asian honey bees in Vietnam for over seven years, by placing microphones in hives belonging to local beekeepers. The study collected almost 30,000 signals made by the bees over 1,300 minutes of monitoring.
“[Bees] are constantly communicating with each other, in both good times and in bad, but antipredator signal exchange is particularly important during dire moments when rallying workers for colony defense is imperative,” researchers wrote in their study.
In some cases, scientists observed that the signals prompted the worker bees at the hive’s entrance to go into defence mode, either attacking the scouting hornet by forming a ball around it to heat it to death or spreading animal dung on the hive to repel predators — the first document use of a tool by bees.
It’s unclear the signals do in fact indicate preparation for a specific type of defence, but as a whole, scientists suggest the the bee pipes are a “rallying call for collective defense.”
Scientists also found ‘striking differences’ in the way the bees responded to two types of predators – the giant hornet which attack in numbers and a smaller hornet species which hunts solitarily. The anti-predator pipes didn’t sound as much as for the latter, suggesting that the response may have been specifically developed for the larger, more dangerous predator.
“Colony soundscapes showcase the diversity of (the bees’) alarm signalling repertoire, including a novel antipredator pipe made by workers when (giant hornet) workers were present at nest entrances,” the study states.
“This research shows how amazingly complex signals produced by Asian hive bees can be,” behavioural ecologist Gard Otis was quoted by science website EurekaAlert! .
“We feel like we have only grazed the surface of understanding their communication. There’s a lot more to be learned.”