Between May and June, the Citizen Observatory of Urban Butterflies counted 28% more species and 74% more specimens than in 2019.
Confinement and rain have triggered butterfly populations in the city of Barcelona, according to the Citizen Observatory of Urban Butterflies (uBMS), which has recorded between May and June a 28% more species different butterflies and a 74% more copies than in 2019.
Entomologists believe that a rainy winter and spring and the interruption of park and garden management tasks from the confinement by the Covid could have increased urban butterflies.
Proliferation in Barcelona
The wavy butterfly (Pararge aegeria), the white cabbage (Pieris rapae) and the fencehopper (Lasiommatamegera) have been the most abundant butterflies in Barcelona, as was the case in 2019, although the volunteers have found one new species in town, the brown-blonde (Hipparchia semele).
On the other hand, Guinardó, Oreneta and Putxet parks They have been the ones that have registered the greatest biodiversity in 2020. According to the project coordinator, this is because they are parks near Collserola and the last two were managed very lightly.
Biologists believe that the most decisive factor for this explosion of butterflies it has been the rain. “The winter and spring have been extraordinarily rainy and that is always good for the butterflies because there is more food available. contamination or human presence affect less to butterfly populations”, according to Melero.
In addition, there is scientific evidence that shows that managing parks and gardens by leaving naturalized areas, with wild flowers, and with little use of pesticides, increases diversity and the number of butterflies in the gardens.
“During confinement, the management of the parks and gardens was stopped, Barcelona was filled with wild plants and flowers and this had a positive effect on butterfly populations”, pointed out Octavi Borruel, head of the Barcelona City Council’s Biodiversity Program.
The city council promotes the Urban Butterfly Observatory project because it forms part of Barcelona’s Green and Biodiversity Plan 2012-2020, which contemplates the possibility of leave naturalized garden areas that help improve biodiversity.