Bumblebees seem to prefer the buzz of the city to the countryside, a large-scale “citizen’s science” study has found.
They also like to have a cool breeze on their backs when foraging, and choose English lavender over the more “flowery” French variety, according to the findings.
Scientists were surprised to receive more bumblebee sightings from volunteers in city centres than in either the countryside or suburbs.
After taking account of factors such as local variations in participant numbers, they concluded that densely packed “flower rich oases” in the form of tubs or baskets of flowers used to brighten up city centres were attracting the insects.
“We asked people to record bumblebees visiting lavender,” said lead researcher Dr Michael Pocock, from the Centre for Ecology Hydrology (CEH) in Wallingford, Oxfordshire. “The rate of bumblebees observed … was higher in cities than in other places, and certainly much higher than in the countryside.
“We were surprised to see more observations in urban localities, as suburban gardens are often thought to be better.
“Bumblebees are visiting (flowers) both for nectar and pollen. A likely explanation is that there’s a concentration effect. Bumblebees will be concentrated on floral resources such as pots and baskets of lavender.”
Colleague Dr Helen Roy, also from CEH, said: “This was an exciting result. I think we can think of cities as quite hostile environments for wildlife. But this shows that we can create oases for wildlife in our cities.”
Areas of greater flower density appeared to be what mattered most to the bees.
Dr Pocock added: “It does suggest potentially one way of boosting and enhancing populations of bees in the cities. If the explanation is this concentration effect then if we plant more floral resources that’s going to have a beneficial effect on populations of bees.”
A total of 30,000 people, mostly schoolchildren, took part in the study this summer, recording more than 4,000 bumblebee sightings from across the UK.
Participants were asked to note how many bumblebees they saw visiting roughly 1ft wide patches of lavender over a period of five minutes. One reason lavender was used was because it is easy for people to identify.
The rate of bumblebee observations was also found to be higher when the weather was both sunny and windy.
Breezy conditions are thought to suit the insects because they help to prevent them overheating, especially on warm days.
“We had some lovely warm days this summer, and the fact that when it was sunny more sightings were reported on breezy days suggest that a breeze has a positive effect on the activity of bumblebees,” said Dr Pocock, speaking at the British Science Festival at the University of Birmingham.
In addition, bees showed a marked preference for English rather than French lavender. Both are introduced species, but French lavender has “highly ornamental” flowers that might impede bees’ access, said the researchers.