PS 39-70 - Data gap or biodiversity gap? Evaluating apparent spatial biases in community science observations of Odonata in the east-central United States

Abstract: Odonates (dragonflies and damselflies) have become prevalent study organisms for insect-based climate studies, due to the taxon’s strong sensitivity to environmental conditions, and an enthusiastic following by community scientists due to their charismatic appearance and size. Where formal records of this taxon can be limited, public efforts have provided nearly 1,500,000 open-sourced odonate records worldwide through online databases, making real-time spatiotemporal monitoring more feasible. While these databases can be extensive, concerns regarding these public endeavors have arisen from a variety of sources: records may be biased by human factors (ex: human population density, technological access, etc.) which may cause erroneous interpretations. Indeed, odonate observations in the east-central US documented in the popular database iNaturalist bear striking patterns corresponding to political boundaries and other human activities.



We conducted a ‘ground-truthing’ study to examine these patterns in an area where community science reports indicated variable species abundance, richness, and diversity which appeared to be linked to observation biases. Five sites were selected across a north-south transect, representing public areas where community members were likely to be present and interacting with odonate populations. Odonates observations were taken using structured sampling methods before being compared to unstructured community science observations for the same areas. In total, this study included 1,573 observations, with 381 originating from structured sampling efforts and 1,192 originating from community science efforts.



For the focal counties and time periods, we found that unstructured community science and structured ‘expert’ sampling performed comparably well in reporting Odonate biodiversity. Both sampling methods reported population composition similarly, though structured sampling showed less variability. In the unstructured data set, reported species richness and abundance varied across the transect route, with extreme ends showing higher measurements than locations intermediate. However, significant discrepancies in the reporting patterns across the transect route for both methods suggest that the drivers behind reported biodiversity could extend beyond strictly anthropogenic forces.