Something New Under the Sun: Assessing the Relative Influence of Sunlight Irradiance and Temperature on Activity Patterns in a Conspicuous Dragonfly

In tropical ectotherms, in addition to environmental temperature, sunlight is also likely a key driver of activity patterns, as increased irradiance enhances the visual efficacy of ornaments. In male amberwing dragonflies ( Perithemis tenera ), despite the importance of thermoregulation, sunlight intensity may be a key determinant of the performance of conspicuous wing displays during territorial contests and mating behavior. In contrast, females possess transparent wings, and their mating behavior consists mainly of brief flights into territories, which may depend directly on thermoregulation. To identify which climatic factors best predict activity patterns in this species, I tested whether sunlight is the primary driver of male territorial activity rather than environmental temperature, and whether environmental temperature is the primary driver of female mate‐searching activity rather than sunlight. I measured territorial activity by males as number of males occupying mating territories and mate‐searching activity as number of females entering in territories. I also collected measures of temperatures and global horizontal irradiance from open‐access data sources. Contrary to my hypothesis, I found that temperature is the primary driver of male territorial activity, indicating that thermoregulation of fighting capacity traits, as thorax muscles, may be determinant on contests for territories. I also found that temperature is the primary driver of female mate‐searching activity, indicating that warmer daily temperatures may enhance oviposition performance. Overall, these results highlight the importance of evaluating climatic factors directly linked to patterns of activity to improve knowledge of mating systems in Global South environments.