LB 10-99 - Identification of overlooked climate-sensitive Odonates across United States watersheds

A pervasive problem in protecting species from extinction in light of climate change is that many remain overlooked until their population sizes become unrecoverable. Sensitive species can be overlooked due to lack of data on life-history, habitat preference, and/or dispersal. These types of data are limited, particularly for rare or cryptic species. Invertebrates, in particular, are disproportionately understudied yet are predicted to be substantially affected by climate change. The Relative Climate Sensitivity Index (RCS) incorporates point occurrences and climate data into a standardized estimate of a species' intrinsic risk of extinction (Mims et al. 2018). Here, we estimated the intrinsic sensitivity for 426 Odonate species native to the United States using over 220,000 occurrence records and publicly-available climate data. We compared intrinsic sensitivity between species requiring lotic habitat for reproduction with those that can breed in lentic habitats. We also compared intrinsic sensitivity ranks to current state, federal, and international conservation statuses to identify species that may benefit from listing but remain overlooked. Finally, we mapped average intrinsic sensitivities across watersheds to help inform efforts at a commonly used geopolitical unit of conservation action. Preliminary results indicate many Odonate species that are not currently listed at the state, federal or international level may be more sensitive to climate change than some species that are currently listed. This was especially the case for Zygopteran (damselfly) species requiring lotic habitat for reproduction. Lotic species were overall more sensitive than lentic species, with lotic damselfly hotspots in the southwest continental U.S. along the border with Mexico and lotic dragonfly hotspots along the east coast, with a few areas near the Great Lakes and Interior Highlands Region of the central U.S. Nearly 56% of all Odonate species are listed by the IUCN but half of them are listed as data deficient. The RCS approach implemented at the watershed level can help determine the intrinsic sensitivity of many freshwater taxa to climate change, identify at-risk species sooner, and may be more appropriate than other landscape grid approaches as watersheds are often the unit of occupancy and dispersal for freshwater taxa.