Butterflies

The third report of the mBMS, Barcelona’s Metropolitan Butterfly Monitoring Scheme, contains some unexpected findings: the beaches in Barcelona’s metropolitan area are not only inhabited by butterflies, but by butterfly communities unlike those found in the local parks. This means that the beaches act as reserves for certain species of butterflies. Some species found in only relatively small numbers in parks are more abundant at beaches, making such seaside environments especially important for biodiversity conservation in the metropolitan area.

Two studies led by Jofre Carnicer, CREAF researcher and professor at the University of Barcelona-IRBIO, show that natural areas that maintain microclimates are more resilient to climate change and biodiversity loss. Both studies conclude that microclimates (areas of natural space with different temperature, shade or humidity) become climatic refuges when there are extreme conditions, and that they should be studied in detail to assess the real impacts of global warming on nature.

The months of lockdown, when less maintenance work was carried out in parks, coupled with one of the wettest springs in recent years, has seen city butterfly populations flourish in Barcelona. Thanks to Barcelona Citizen Observatory for Urban Butterflies lead by CREAF, some 28% more butterfly species were recorded in the city between May and June this year, with 74% more individuals than for the same period last year.

The observatory is the first of its kind in Spain and CREAF is coordinating the team of scientists behind it. They will be working with volunteers to monitor the evolution of butterfly populations in 54 parks and gardens in Barcelona and Madrid.

We interviewed Yolanda Melero, holder of a PhD in biology, whose studies have revolved around the behaviour and dynamics of American mink populations. At CREAF she is continuing to investigate how animal populations function, but is now focusing on butterflies to learn about biodiversity-friendly city design.

CREAF researchers signal climate change and changes in land use as the principal causes. The most impacted are specialized species living in very specific habitats and those producing a number of generations in a single year. 

A study finds that high temperatures and low rainfall cause a timing mismatch between the flowering period of plants and the time of flight of butterflies. The moments of maximum florescence and butterfly abundance are separated by a mean time of 70 days, increasing in years with marked drought. 

According to a study in which CREAF participated, the populations of birds or butterflies living in open habitats have been negatively affected by the loss of field and scrubland habitat. Conversely, species which live in forests have been favored. These variations were related with changes in the Catalonian (and Mediterranean) landscape over the last few decades.