This summer of 2023 all historical temperature records will be broken, impacting a wide range of animal species. In particular experts from observatories from butterfly chase In the cities, the uBMS and the mBMS have registered that their occurrence in urban areas is significantly lower this year.
The main cause is the severe drought in which we find ourselves, causing the vegetation to dry out, both in urban parks and gardens and in the dunes of the beaches and in the grasslands of the natural areas of the cities.
“Since it doesn’t rain and they can’t be watered, the plants dry up the butterflies They stay no food available. In parks like the Maternitat de Barcelona there are still some flowering areas and it is obvious that the few butterflies that exist are concentrated there,” he explains. Yolanda MeleroResearchers at the Center for Ecological Research and Forest Applications (CREAF) and the University of Barcelona.
The results of this “catastrophic” summer, according to experts, will not be known in detail until the end of the season, in October, but the experiences of volunteers and scientific visits to parks and gardens already clearly show this trend.
On the other hand, episodes of intense heat Repeated surfacing also prevents us from seeing butterflies because the over-temperature reduces them survival and reproduction and because some species venture to higher elevations or further north to find the vegetation they need.
To regulate their body temperature, butterflies fly less on these hot days.
additionally Caterpillars are more sensitive as adult butterflies and can die from dehydration. It should be remembered that there are butterflies bioindicator speciesthat is, they inform us of what is health status of ecosystem in which they live. Therefore, the fact that butterfly populations are declining due to drought and heat can be extrapolated to other arthropods such as bees or beetles and even some vertebrates.
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In addition to these survival and reproductive changes, butterflies also change their behavior to try to survive these situations. First, stay in cooler and shady areas and we do not see them in the sunniest meadows.
Butterflies also regulate their body temperature they fly less On those hot days (shade day) they even spread their wings at the right angle so that they are not exposed to direct sunlight.
Mobility patterns are also changing and they arrive less or less in urban centers where the temperature is even more pronounced due to climate change heat island effect. According to Melero, “When the butterflies move, they process the information and are able to see what is outside of the most natural areas like Collserola and Montjuïc.” few places with water and flowers, and they spread even less towards the inner city. You take no risk.