Distributional changes in the swamp tigertail (Synthemis eustalacta, Anisoptera: Synthemistidae) over the past decade

Intensity in bushfires in Australia have increased in the past few decades due to climate change, threatening habitat loss for numerous species. Although the impact of bushfires on vertebrate taxa is well documented, the effects of bushfires on the distribution of arthropod taxa is seldom studied. Understanding the distribution of arthropod taxa after bushfire seasons could elucidate long-term impacts and recovery of ecosystems. This study aims to understand the effects of bushfires on the distribution of the Swamp Tigertail Synthemis eustalacta (Anisoptera: Synthestidae) by modeling habitat suitability over the past decade. Yearly occurrences records were derived from museum collections and research-grade citizen science data during peak breeding season, and temporally matched with monthly environmental layers at peak fire season. We evaluated two models: largescale climactic variables, and a combined model including regional vegetative land cover variables. We selected optimal models which possessed the highest AUC value and lowest omission rates and determined their performance on spatially withheld data. Within our largescale climactic model, maximum and minimum monthly temperature possessed the highest relative contribution. Percent tree cover possessed the highest contribution within our combined model, and burned area possessed minimal contribution. Shade is hypothesized to affect the physiology of S. eustalacta suggesting that loss of tree cover by fires may possess indirect effects on the distribution of the species. These results represent the first temporally based approach to distributional estimates within a dragonfly species and demonstrates the benefits of SDM-derived habitat suitability in the conservation of landscapes after disturbance events.