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Nature: Male honeybees mass in certain areas ‘like men in nightclubs’, but females appear rarely

Just like ‘men in nightclubs’, male honeybees, or ‘drones’, swarm in certain areas when looking to mate, but female queen bees only make rare appearances.

Experts from Queen Mary University of London and Rothamsted Research used radar technology to track drones and reveal the secrets of their mating behaviours.

Drones were fitted with small, antennae-like transponders on their backs which reflected radar signals at a higher frequency, allowing flight paths to be monitored.

Researchers have long suspected that male bees gather in large groups of up to 10,000 individuals, aiming to fulfil their goal of mating with a queen in mid-air.

But previous analyses of bee behaviour used pheromone lures to attract drones, raising the possibility that the lures were causing the congregations.

The new work, however, proves they occur naturally, and reveals for the first time that the male bees also move between different congregation sites.

According to the researchers, virgin queens were harder to track, but also appear to gravitate towards the drone congregation areas in order to mate.

Yesterday’s publication of the study coincided with the UN’s World Bee Day, which aimed to raise awareness of the importance of pollinators and the risks they face. 

Just like ‘men in nightclubs’, male honeybees, or ‘drones’ (pictured , swarm in certain areas when looking to mate, but female bees only make rare appearances

Experts from Queen Mary University of London and Rothamsted Research used radar technology (pictured) to track drones and reveal the secrets of their mating behaviours

Experts from Queen Mary University of London and Rothamsted Research used radar technology (pictured) to track drones and reveal the secrets of their mating behaviours

Drones were fitted with small, antennae-like transponders on their backs (as pictured) which reflected radar signals at a higher frequency, allowing flight paths to be monitored.

Drones were fitted with small, antennae-like transponders on their backs (as pictured) which reflected radar signals at a higher frequency, allowing flight paths to be monitored.

LEKS EXPLAINED 

According to the researchers, the gatherings of the bees function like so-called ‘leks’.

Seen most prominently in vertebrates like deer and grouse, leks are mating systems where males gather together en mass in one area to reproduce.

However, unlike with the bees, leks tend to manifest as single — rather than multiple — gathering sites.

In the study, the team were able to track the bees’ positions related to a radar dish every three seconds with an accuracy of around two metres, which they then refined by making use of known landmarks around the outdoor field site. 

‘By using harmonic radar technology to track the bees, we found that individual flight paths show a clear change of behaviour from straight flight to looping flight,’ said behavioural ecologist Joe Woodgate of Queen Mary University of London.

‘Periods of looping flight were clustered in particular locations and repeatable over two years, confirming that stable drone congregation areas, similar to “leks” in other species, do exist.

‘We show that drones frequently visited more than one congregation area on a single flight.

‘This is the first evidence for males of any species routinely moving between lek-like congregations and may represent a new form of mating system in honeybees.’ 

Speaking to The Times, Dr Woodgate compared this behaviour to that of men in nightclubs. 

He explained: ‘You could think of them as being something like nightclubs,.

‘The boys are all there because they think they’re going to meet girls, and the girls are going there because they think they’re going to meet boys.’

According to the researchers, the behaviour of drones seen within the congregation areas bears similarities to how midges and mosquitos act when swarming.

According to the researchers, the behaviour of drones (pictured) seen within the congregation areas bears similarities to how midges and mosquitos act when swarming

According to the researchers, the behaviour of drones (pictured) seen within the congregation areas bears similarities to how midges and mosquitos act when swarming

When flying around in loops in one of the areas, the team noted that the further the bees travelled from the centre, the harder they would go on to accelerate back towards it.

This creates an apparent force, drawing bees towards the centre and helping to forge a coherent swarm even while individual drones only spend short amounts of time in each individual location.

The researchers noted, however, that it is not yet clear how drones find congregation areas in the first place, especially given that drones — who are born in summer and only live for 20 days — are unable to learn from past generations.

‘Our findings suggest drones locate congregation areas as early as their second ever flight, without apparent extensive search, said paper author and behavioural ecologist Lars Chittka, also of Queen Mary University of London.

'By using harmonic radar technology to track the bees, we found that individual flight paths show a clear change of behaviour from straight flight to looping flight,' said behavioural ecologist Joe Woodgate of Queen Mary University of London. 'Periods of looping flight were clustered in particular locations [as pictured] and repeatable over two years, confirming that stable drone congregation areas, similar to "leks" in other species, do exist'

‘By using harmonic radar technology to track the bees, we found that individual flight paths show a clear change of behaviour from straight flight to looping flight,’ said behavioural ecologist Joe Woodgate of Queen Mary University of London. ‘Periods of looping flight were clustered in particular locations [as pictured] and repeatable over two years, confirming that stable drone congregation areas, similar to “leks” in other species, do exist’

‘This implies that they must be able to get the information required to guide them to a congregation from observing the landscape close to their hive.

‘In the future, we will look at how they accomplish this feat.’

Dr Woodgate is also part of a project called ‘Brains on Board’, which aims to create robots with a navigational ability patterned on those of bees.

‘We believe that bee-inspired robotics will play a role in improving robotics and artificial intelligence in the future,’ he explained.

‘Understanding how bees select and find distant goals based on their explorations of their surroundings will be important for this.’

The full findings of the study were published in the journal iScience.

DECLINING BEE POPULATIONS

Declines in recent months to honey bee numbers and health caused global concern due to the insects’ critical role as a major pollinator.

Bee health has been closely watched in recent years as nutritional sources available to honey bees have declined and contamination from pesticides has increased.

In animal model studies, the researchers found that combined exposure to pesticide and poor nutrition decreased bee health.

Bees use sugar to fuel flights and work inside the nest, but pesticides decrease their hemolymph (‘bee blood’) sugar levels and therefore cut their energy stores.

When pesticides are combined with limited food supplies, bees lack the energy to function, causing survival rates to plummet.

Read more at DailyMail.co.uk