LB 9-80 - Assessing recent and future climate impacts on Papilio spp. and their hostplants

Background/Question/Methods:

Changes in global temperature and increasing aridity profoundly impact many aspects of the biosphere. Many of these interactions are negative, yet some species and their ecological relationships may benefit from these new climatic circumstances. Species distribution models of North American Papilio species (n=16) and all of their associated plants (n=156) were created using data from GBIF, which includes museum records as well as community science data from iNaturalist and eButterfly. Models were based on the standard 19 bioclimatic variables and used to estimate contemporary distributions of butterfly species and host plants. The same models were used to predict future distributions of butterfly and plant species, using the CMIP6 dataset of forecast environmental variables for 2070. Contemporary and forecast estimates were compared when the total area of butterfly species’ ranges was predicted to overlap with at least one host plant species.

Results/Conclusions:

We find changes in area are marked by significant differences between species in western North America and species in eastern North America, where western species were more likely to face reductions in area. All but one species occurring in arid regions are predicted to have a contracted geographic range in 2070, while non-arid species were less likely to have range contractions by 2070. Changes in individual species’ ranges will further influence regional species richness across North America. Estimates of individual species’ predicted ranges were also used to estimate species richness, combining predictions of all North American Papilio species for the two time periods, contemporary and 2070. Contemporary estimates indicate western North America has slightly higher Papilio species richness than other parts of the continent. However, future climate conditions indicate a decline of species richness in the arid southwest and intermountain west. These findings have the potential to improve conservation and restoration efforts of these butterflies and their larval habitat across North America.