ITHACA, N.Y., Dec. 12 (UPI) -- As spring arrives earlier each year as a consequence of global warming, bees and plants seem to be keeping pace, U.S. researchers say.
An analysis of bee collection data over the past 130 years by Cornell University researchers shows spring arriving about 10 days earlier than in the 1880s, and bees and the lowering plants they seek have matched that, arriving earlier in lockstep.
Most of this shift has occurred since 1970, a period with the most rapid increases in mean annual temperature, Cornell entomologist Bryan Danforth said.
Danforth and colleagues made extensive use of existing collections of data and specimens held at Cornell, a university release said Monday.
"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," Danforth said.
The actual triggers for bee spring emergence are unknown, he said, but the insects may simply be prompted to emerge when temperatures rise above a certain level 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," Danforth said.