In the past 18 months humans have become all too familiar with the term “social distancing”. But it turns out we are not the only ones to give our peers a wide berth when our health may be at risk: research suggests honeybees do it too.
Scientists have found that when a hive of honeybees is under threat from the mite Varroa destructor – a parasite linked to the collapse of honeybee colonies – the bees respond by changing the way they interact with one another.
“If you think we have a brain, we’re conscious, but it took us time to change our everyday behaviour [in response to Covid], I think it’s exciting to see that other animals are doing something similar,” said Dr Alessandro Cini, co-author of the research at University College London.
Writing in the journal Science Advances, Cini and colleagues describe how they first looked at beehives in Sardinia, Italy, and compared the behaviour of bees in hives that were naturally infected with the mites, to those in hives which had been treated to get rid of the parasites.
By examining videos recorded inside the hives, the team found that when the hive is infested with mites, foraging bees – which tend to be older members of the colony – performed important dances to indicate the direction of food sources, such as the waggle dance, away from the centre of the colony where the young bees, the queen and brood cells are found.
That, said Cini, may help to keep the infection at a level that can be controlled, limiting the amount of damage. “Foragers are one of the main entrance routes for the mites,” said Cini. “So the more they stay away from the brood and the young individuals, the better it is in terms of preventing the spread of the mites within the colony.”
The team also found changes in where bees groomed one another: in uninfected colonies this tends to be concentrated among the young in the central part of the hive, but the researchers found this was even more the case when mites were present. “They’re probably concentrating their thoughts [efforts] toward the more important part of the colony, leaving the grooming of foragers,” said Cini.
The team then carried out experiments in the laboratory, artificially infecting small groups of about 12 young bees with the mites and comparing them to uninfected groups. This time, the team found no increase in social distancing among infected groups – which, says Cini, may reflect that it is more important for foragers and young bees to keep their distance when mites are present, and that bees rely on one another.
“Probably social distancing is too costly at small scale,” he said.
But again, there were differences in grooming behaviour: infected bees were groomed more, inspected more, and had food shared with them more than individuals in uninfected groups.
Cini said the study showed the power of natural selection in the evolution of social behaviour. “And also dynamic change in the social behaviour to adapt to an ever-changing environment,” he said.
Source & Credit – The Guardian Newspaper