Climate change has led to changes in phenology, which is hypothesized to have a large impact on species interactions. We examine the phenological shifts in flowering time for a suite of common nectar-producing plants in Western Washington and Oregon. We used museum specimens of one butterfly, the Boisduval’s blue (Icaricia icarioides), to determine if there are resource mismatches with the butterfly. We address the following questions: (1) What are the trends in changing phenology for the butterfly and nectar plant community? and (2) Is there a balance between lost interactions and new interactions? We evaluated phenology for Boisduval’s blue and 58 current and potential nectar species. We implement quantile regression to address these questions.
Results/Conclusions
Overall, the butterfly is advancing more rapidly (~0.4 days per year) than all but one of the nectar plants. We found that only nine nectar species have a stable phenology for the past 120 years. Advances were slightly more common than delays, with 27 species advancing and 21 species delaying phenology. We project that Boisduval’s blue may soon experience more mismatches than detected in the historical record, and this could continue through the first half of this century. However, there is a smaller suite of species projected to begin overlapping well with the butterfly if the linear advance continues. Many pollinators and beneficial insects use these plants, which indicates that the next 20 years or so may see an increase in resource mismatches for those insects. These results emphasize the need to consider phenology alongside species diversity to create more climate resilient communities.