Bad news for the American bumblebee in Canada. Scientists took a new look at how the tiny insect—once widespread throughout its native North America—is faring, and found it may now be facing extinction up north.
The American bumblebee species (Bombus pensylvanicus) has decreased by 70 percent within its known Canadian boundaries, according to a study published on Wednesday in the Journal of Insect Conservation. Its relative abundance, or representation throughout its local ecosystem, also plummeted 89 percent from 2007 to 2016 compared to 1907 to 2006.
These declines, the study notes, are enough to warrant a new classification on the International Union for the Conservation of Nature (IUCN) Red List—an extinction risk masterlist of the world’s plant and animal species. The species is currently listed as “vulnerable,” or “considered to be facing a high risk of extinction in the wild,” according to IUCN’s own definition.
“This species is at risk of extinction and it's currently not protected in any way despite the drastic decline,” Sheila Colla, an assistant professor of environmental studies at York University in Toronto and co-author of the study, said in a statement.
Colla was one of three researchers who pored over data from citizen science programs, a North American bumblebee catalog dating back to the late-1800s, and their own field surveys to paint a comprehensive portrait of the species’ fate in Canada.
“This bumblebee species now has a reduced overall range,” explained Victoria MacPhail, a PhD student at York University and co-author of the study, said in a statement. “It used to stretch from Windsor to Toronto, and all the way to Ottawa and into the Quebec area, but it is now only found in some core areas and has experienced a 37 percent decrease in overall range. It's now a rare sighting in Toronto.”
MacPhail isn’t entirely sure what’s causing the American bumblebee’s swift decline, CBC reported on Monday. But one probable culprit is grassland habitat loss in Canada due to agriculture, MacPhail speculated. Other factors could be diseases spread by invasive bumblebees, and climate change which may be harming plants that bumblebees depend on and may also forcing them into new ranges.
The study hopes the American bumblebee’s IUCN Red List ranking will be amended to reflect it’s dire status—and that direct conservation efforts will be taken to save the imperiled species.
“Now that we have assessed the extent of the decline and located where the remaining populations are,” Colla said, “we can look more closely at threats and habitat requirements to design an effective conservation management plan so that this species does not disappear from Canada forever.”