Climate crisis is not only giving rise to extreme weather conditions and melting glaciers but also affecting wildlife. In a study published in Proceedings of the National Academy of Sciences, a group of scientists have found that male dragonflies are exhibiting changes in the pigmentation of their wings as a coping mechanism against rising temperatures.
Michael Moore, postdoctoral fellow with the Living Earth Collaborative, Washington University in St. Louis led the research. The team of scientists also included director of Washington University’s environmental field station, Tyson Research Center, Kim Medley and Kasey Fowler-Finn, an associate professor of biology at Saint Louis University, and Washington University undergraduates.
The team of researchers created a database of 319 species of dragonfly using field guides and citizen-scientist observations for the study. The wing composition shown in photographs submitted to iNaturalist was examined as the team of scientists gathered information about climate variables in the locations. From almost 3,000 iNaturalist observations in a focused group of 10 selected species, scientists measured the amount of wing pigmentation on a single dragonfly. The study focused on how dragonflies in each of the 10 species differed in the warm and cool parts of their geographic ranges.
In a statement, Moore said that several dragonflies have patches of dark black colour on their wings that they use to attract potential mates and intimidate rivals. However, having dark pigmentation on the wings can increase the body temperature of dragonflies by as much as 2 degrees Celsius, said Moore. Although the pigmentation originally served the purpose of helping dragonflies find mates, global warming could also cause them to overheat in regions that are already hot.
In their findings, researchers found that male dragonflies almost always responded to warmer temperatures by evolving less wing pigmentation, in both hotter and cooler geographic ranges. The finding was true for populations of the same species that live in warmer areas and cooler areas also. Moore said that since our planet is expected to continue to witness rising temperature, the results of their study suggest that dragonfly males may eventually need to adapt to global climate change by evolving less colour on their wings.