Dragonflies change their colors throughout the year

A study conducted by researchers at Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany, discovered that dragonflies undergo seasonal color changes in response to variations in solar radiation. This finding sheds light on the remarkable adaptation strategies of these predatory insects.

The role colors play in dragonflies

The researchers found that in spring and autumn, dragonflies with darker color nuances are more likely to take flight, while during the summer months, lighter-colored specimens prevail.

This observation led the scientists to conclude that the color adaptation of dragonflies plays a crucial role in regulating their body temperature. The rationale behind this lies in the fact that dark colors are more efficient at absorbing heat compared to lighter colors.

Professor Christian Hof, the head of the Chair of Global Change Ecology at JMU, explains that it is not individual animals that change their colors, but rather, it is the average coloration of the entire population at any given time that adjusts to solar radiation.

“What changes and adapts to solar radiation, so to speak, is the average coloration of all dragonflies flying at any one time,” said Hof.

This ability to alter their color collectively enables dragonfly communities to optimize their thermal dynamics and thrive in various conditions.

Dragonfly geographic distribution and colors

Prior research has shown that, in northern regions where temperatures are colder, darker-colored and larger dragonfly species tend to dominate due to their enhanced heat retention capabilities.

Conversely, in sun-drenched southern areas, lighter-colored dragonfly species prevail as their coloration protects them from overheating. This study builds upon this existing knowledge and provides further insights into the intricate relationship between coloration, temperature regulation, and geographic distribution.

To delve deeper into the phenomenon of seasonal color change, Dr. Roberto Novella-Fernandez and Professor Christian Hof meticulously examined and analyzed scientific observation data of dragonfly communities in the United Kingdom spanning from 1990 to 2020. The findings were profound.

“For the first time, we were able to prove that the average body brightness of dragonflies not only differs between warmer and colder regions but also reveals a distinct seasonal variation. Lighter species tend to be found during months with stronger sunlight, particularly summer, while darker specimens take flight in spring and autumn,” explains Roberto Novella-Fernandez, the lead author of the study.

Climate change implications

The study also uncovered an intriguing connection between climate change and the observed seasonal color variation. The evaluated data revealed that this natural color adaptation has undergone changes over the course of climate change. However, it is worthy to note that the primary influence of global warming is on temperature, rather than solar radiation.

As a result, this shift in environmental conditions may render the dragonflies’ coloration less optimal, making it more challenging for them to fly under ideal solar radiation conditions. Novella-Fernandez highlights the importance of understanding this aspect in more detail, stating, “Understanding the precise implications of these changes is one of our forthcoming goals.”

In collaboration with their counterparts from the Philipps-Universität Marburg, the researchers were able to utilize the available data on the color characteristics of dragonflies to investigate the relationship between changes in species’ traits, such as coloration, and environmental transformations. This approach allows for a more comprehensive understanding of the factors influencing biodiversity loss.

Implications of dragonfly color change

Christian Hof concludes by highlighting the significance of their research group’s contribution to this area. “The aim of our research group at TUM, which received funding from 2018 to 2023 as part of the Bavarian Climate Research Network bayklif, was to contribute to this cause. We are determined to continue our important work at the renowned University of Würzburg,” said Hof.

In summary, the remarkable color adaptation exhibited by dragonfly communities in response to seasonal fluctuations in solar radiation adds a captivating facet to our understanding of their ecological strategies. This study unveils the physiological and ecological significance of dragonflies’ coloration and highlights the potential impact of climate change on these magnificent creatures.

By investigating the intricate interplay between environmental factors and species characteristics, scientists can gain valuable insights into the causes of biodiversity loss, ultimately contributing to the safeguarding of our natural world.

The full study was published in the journal Nature Communications.

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