Although the increase of average temperatures across the world could improve the flight of bee species in colder climates, scientists have found that the rise of extreme weather could “push them past their limits.”
Researchers from Imperial College London assessed the correlation between the existing temperature and the flying “performance” of bumblebees, which was published in the Functional Ecology journal.
The researchers studied the bumblebees’ flight stamina as well as their willingness to fly, finding that flying was most successful from 12 Celsius and reached its highest point at “25-27” Celsius. Although, they concluded that there was a drop in flight performance further on from this temperature.
In the last few weeks, the level of heat in parts of the US, Canada, Siberia and Europe have been higher than 27 Celsius, which suggests that the bees may be under threat.
According to the researchers, the results indicate that although bumblebees from northern latitudes may improve flight levels during warmer weather, the southern latitude counterpart may be at a disadvantage, where it is more common for temperatures to go over 27 Celsius.
The first author Daniel Kenna, who is from Imperial College London said: “Climate change is often thought of as being negative for bumblebee species, but depending on where in the world they are, our work suggests it is possible bumblebees will see benefits to aspects of an important behaviour.”
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Kenna added: “However, more extreme weather events, such as cold snaps and the unprecedented heatwaves experienced in recent years, could consistently push temperatures beyond the comfortable flight range for certain species of bumblebees.”
The Independent reports that the role of temperature is crucial in enabling an insect’s ability to fly. Temperatures that are too cold can weaken bees’ muscles, causing them to struggle to fly, whilst soaring temperatures may cause bees to “overheat.”
In order to find how temperature has an effect on flight quality, the bumblebees were “temporarily attached” to “flight mills,” an apparatus, which made the bees fly in a circular direction, described as “a carousel,” ultimately recording the speed and distance of flight.
The bees were diverse in size and tested at temperatures ranging from 12 to 30 Celsius. The results indicated that although bumblebees are able to fly for approximately 3 kilometres, this average could be dropped to under 1 kilometre should the temperature reach 35 Celsius. What’s more, at 10 Celsius, the flight range can be just a few hundred metres.
When the temperature was 15 Celsius or below, the researchers found that the bees were not striving to fly and mostly did not fly more than 100 metres. However, larger bees managed to fly at these cooler temperatures, implying that the smaller ones are not at their peak flight in a cooler climate and that climate warming could be to their advantage.
So whilst climate change is a worrying environmental issue, it could be beneficial for certain bee species. However, a surge in temperatures is equally detrimental to the bee population’s agility; and a lack of flight could lead to a drop in pollination, which is a palpable threat to our ecosystem.
Much of our agriculture depends on bee pollination. It’s not just a matter of fabricating honey. Beehives are rented out to pollinate farmers’ crops. Over one third of the food we eat relies on pollination by bees, either directly or indirectly. Therefore, one must be careful to assess threats from climate change: Some are good, others are bad, they all require careful study to understand the final impact.
Editor’s Note: The opinions expressed here by Impakter.com columnists are their own, not those of Impakter.com.— In the Featured Photo: Bumblebee on Lavender. Featured Photo Credit: Marcus Ganahl