No laggards, those bees and plants. As warm temperatures due to climate change encroach winter, bees and plants keep pace. An analysis of bee collection data over the past 130 years shows that spring arrives about 10 days earlier than in the 1880s, and bees and flowering plants have kept pace by arriving earlier in lock-step.

The study also found that most of this shift has occurred since 1970, when the change in mean annual temperature has increased most rapidly, according to Bryan Danforth, Cornell professor of entomology, who co-authored a study published the Proceedings of the National Academy of Sciences.

"It's an illustration of how valuable our natural history collections are at Cornell, even if you don't know in advance how these collections might be used," says Danforth. Lead author Ignasi Bartomeus and senior author Rachael Winfree are both entomologists at Rutgers University.

Although the triggers for bee spring emergence are unknown, bees may simply be cued to emerge when temperatures rise above a threshold over a number of days, but "if climate change accelerates the way it is expected to, we don't know if bees will continue to keep up," says Danforth.

Co-authors include researchers from the American Museum of Natural History, University of Connecticut, and York University in Canada. Jason Gibbs, a Cornell postdoctoral associate, conducted and supervised a team of undergraduates entering bee data at Cornell.