Sheila R. Colla

TL;DR: Using long-term observations across Europe and North America over 110 years, testing for climate change–related range shifts in bumblebee species across the full extents of their latitudinal and thermal limits and movements along elevation gradients found cross-continentally consistent trends in failures to track warming through time at species’ northern range limits.

TL;DR: It is reported that over the past 130 y, the phenology of 10 bee species from northeastern North America has advanced by a mean of 10.4 ± 1.3 d, suggesting that bee emergence is keeping pace with shifts in host-plant flowering, at least among the generalist species that were investigated.

TL;DR: It is argued that the spillover of pathogens from commercial to wild bees is the most likely cause of this pattern and the implications of such spillover for bumble bee conservation are discussed.

TL;DR: An impoverishment of the bumblebee community in southern Ontario over the past 35 years is documents and the extent of range decline for a focal species was estimated by surveying 43 sites throughout its known native range in eastern Canada and the United States.