Combining SDMs and trait-vulnerability assessments to determine how Canadian birds are impacted by climate change

Background/Question/Methods

To cope with climate change, many species are shifting their ranges to higher latitudes. In North America, higher latitudes are already heavily used by many birds as breeding grounds, who are experiencing increased biotic and abiotic pressures. Between the Arctic warming three times faster than the rest of the world and birds having to push their already northern breeding range even further north, northern species are particularly vulnerable. Many studies have looked at how climate change is impacting birds across the globe, but few have focused solely on the one place experiencing the greatest magnitude and rate of change: Canada. Here, we investigate how Canadian breeding birds are impacted by climate change at a finer scale, while also looking at how functional traits are correlated with vulnerability. We used various SDMs to predict species potential distribution with both climate and environmental predictor variables relevant to northern latitudes. We obtained occurrence data from GBIF, filtering for breeding data only (June, July) and used IUCN breeding polygons to remove outliers in the distribution data. Furthermore, we developed and performed a trait vulnerability assessment (TVA) which incorporates functional traits that reflect a species exposure, adaptive capacity, and sensitivity to climate change.

Results/Conclusions

By incorporating the SDM results into our TVA framework, we uncovered which aspects of a species life history makes them more vulnerable to climate change. We found that waterfowl and shorebirds are expected to lose the most habitat, with a decrease of 26% and 17% in suitable habitat, respectively. Seabirds are expected to experience the largest increase in habitat, increasing their suitable habitat by 19%. Moreover, species listed as least concern have a significant difference in their traits associated with sensitivity, but not with traits associated with exposure and adaptive capacity compared to species listed as near threatened or vulnerable. Knowing which species are expected to lose or gain habitat provides information needed to implement targeted conservation and management measures. Furthermore, with many birds expected to experience a decrease in range size by more than 50%, identifying traits which make birds more vulnerable to climate change is key to help promote their persistence with more global changes coming.