Sex in the City: Reproductive Behaviors of Dragonflies across an Urban Landscape

Anthropogenic cityscapes provide complex habitats that influence animal communication and movement patterns, which are generally understudied in aquatic and semi-aquatic organisms. Community science, referring to public participation in scientific research, is an important tool for recording occurrence records and behavioral observations of understudied urban species. Boise, Idaho (USA), one of the fastest-growing cities in North America, has a long-established community science program for documenting occurrences of the semi-aquatic insect order Odonata (dragonflies and damselflies), making the city an ideal study system for comparing behavioral observations from community science with observations recorded using AI driven iNaturalist. In this study, we test the accuracy of iNaturalist observations and volunteer surveys to characterize dragonfly reproductive behaviors (tandem flight and tandem perching, oviposition, and mating) in the city, and use these observations to determine which dragonflies are using the urban landscape as reproductive habitat. The total numbers of species observations by volunteers and on iNaturalist in Boise were strongly correlated, while reproductive observations showed a strong observational threshold, as reproductive behaviors were rarely identified in less-observed species. iNaturalist tended to underrepresent total occurrences of ''flyer'' species, which rarely perch, while volunteer surveys underrepresented occurrences and reproductive behaviors of a more cyclical species that did not appear to be abundant in the field season in which this study was conducted. Our findings suggest that Boise provides suitable breeding habitat for both migratory and resident dragonflies. Species distribution models of three migratory and three putatively migratory species further demonstrate that these species would be expected in southwestern Idaho regardless of the presence of a city, and have persisted through urban development. This research demonstrates the value of community science in conducting basic research on understudied urban-dwelling species, although findings must be considered alongside potential biases.