According to the study, little butterflies with lighter colors, especially those from the Lycaenidae family, have difficulty controlling their body temperatures when the ambient temperature rises, unlike their counterparts with bigger wings and darker colors.
The influence of color was unexpected and “may be a pattern specific to butterflies,” according to main research author Esme Ashe-Jepson, a doctoral student in zoology at the University of Cambridge in the United Kingdom. Size frequently affects an insect’s ability to tolerate heat.
Throughout the investigation, butterflies with darker wings consistently performed better, regardless of wing size. The research, which was released on July 12 in the Journal of Animal Ecology, provides fresh proof of the important responsibilities that wings play in keeping butterflies cool.
Butterflies require the sun’s warmth to survive. However, when conditions get extremely hot, they use techniques known as thermal tolerance and thermal buffering to regulate their body temperature in proportion to the atmospheric temperature.
Physical actions like migrating into a cooler, shadier place or slanting wings away from the sun are examples of thermal buffering.
According to the study, butterflies with larger wings may be able to go to a cooler place more quickly than those with smaller wings because they have more surface area to absorb heat when necessary.
Mapping the Climate Threat
The synthesis of heat shock proteins is one example of a physiological mechanism that is involved in thermal tolerance. According to Ashe-Jepson, “many animals, including butterflies and humans, produce these molecules to protect themselves from high temperatures.”
They aid in stabilizing and repairing body proteins damaged by extreme heat.
However, that procedure depletes a butterfly’s energy, frequently at the expense of development or reproduction. The findings of this study supported past studies that showed butterflies tended to rely on either thermal buffering or thermal tolerance rather than both, making certain species more susceptible to the effects of the climate crisis’s rising temperatures.
Researchers from the University of Cambridge and the Smithsonian Tropical Research Institute captured tropical butterflies in numerous habitats throughout Panama during both the wet and dry seasons between February 2020 and March 2022 to determine whether there was a relationship between thermal buffering and thermal tolerance in a variety of species of tropical butterflies.
For the thermal buffering test, the researchers caught, analyzed, and then released 1,334 butterflies from 54 species across six butterfly families. “My team and I spent many laborious days walking throughout the rainforest in Panama with butterfly nets. “We didn’t want to pursue the butterfly; we wanted to catch it,” Ashe-Jepson said.