Athens: In a controlled enclosure in a zoo outside Athens, multi-coloured butterflies suck sweet juice from orange slices, free from the hazards of a changing climate outside that are threatening populations in Greece and across the world.
Warmer temperatures are making life harder for butterflies in Greece, home to some 237 species. Food is scarcer, flowering periods are shorter, and experts now suspect the butterflies may be getting smaller.
The problem is echoed globally, including in Mexico and Britain where numbers of some species have declined sharply.
"Climate change is impacting butterflies ... that rely on temperature to perform essential activities such as mating, reproduction, growth, and feeding," said Konstantinos Anagnostellis, an agronomist.
Anagnostellis is part of a team in a research project called MEIOSIS - the Greek word for shrinking - by the Greek University of Ioannina. It involves measuring the body weight of more than 50,000 butterfly specimens over a century to model their decreasing body size in response to climate change.
Heat forces butterflies to fly to cooler places where there is less food. Worsening wildfires in Greece also reduce access to food because of the loss to grasslands, Anagnostellis said.
"If these plants are burned, there is a risk of direct mortality for the larvae, and we may not have adult butterflies to reproduce, forcing them to migrate to other areas."