Honeybees may be getting the bulk of media attention when it comes to declining populations.
But researchers in the Northeast say that bumblebees have taken a much larger hit during the past century and a half, according to a recent news release.
They blame it mostly on human encroachment, which has fragmented their habitats.
The researchers studied more than 30,000 museum specimens representing 438 bee species in collections at Cornell University, the American Museum of Natural History in New York City, Rutgers University and the University of Connecticut.
The specimens were collected from 1872 to 2011.
Although they found slight declines in the number of bee species over time, they found that more than half of all bee species changed in relative size proportion.
In other words, species found in lower numbers have shifted toward having larger body sizes and more restricted diets and are active fewer months of the year.
The researchers found three bumblebee species suffered recent, rapid population collapses: the rusty-patched bumblebee, a pollinator for potatoes and apples; Bombus pensylvanicus and and B. ashtoni.
The researchers from Cornell University, Rutgers University and the American Museum of Natural History reported their findings in the Proceedings of the National Academy of Sciences online, March 5.