Background/Question/Methods: Global climate change is one of the top drivers of species extinctions in the past several decades. Biodiversity declines increase as novel climatic conditions push species outside of their climatic tolerances, making persistence unlikely. Changes in distribution and phenology are the predominant climate change responses across taxa. However, the interactions of these climate responses are poorly understood. I use bumblebees (Bombus) as a model to understand the relative importance of phenological and range shifts as responses to climate change. Bumblebees are valuable pollinators of crops and flowering plants worldwide and have experienced significant range losses over the past five decades. I investigate whether probability of Bombus species persistence across Canada and the United States depends on ability of species to track climate through emergence and peak phenology, and whether closely related species exhibit similar degrees of phenological change and similar persistence probabilities. I analyze over 13 000 georeferenced occurrence data points from Canada and the United States for 15 Bombus species. I compare annual emergence timing with spring onset dates during a baseline period, 1954-1970, to a recent period, 2006-2014. I collect data on annual spring onset timing from Natural Resources Canada datasets. To determine whether phenological plasticity is phylogenetically biased, I create a phylogenetic tree using published C01 mitochondrial gene sequences. I test for phylogenetic signal using Pagel’s λ. Results/Conclusions: 15 species are found to track spring onset through shifts in emergence and/or peak phenology (R2 > 0.2, p-value <0.05 in all cases). All 25 species show a moderate positive correlation between persistence probability and strength of climate-phenology relationships. No phylogenetic bias of phenological change is detected. Clarifying the interaction between spatial and temporal shift patterns of Bombus species improves understanding and predictions of climate-driven declines. This mechanism of climate change response can be applied across animal taxa to aid biodiversity conservation efforts.
