A new study from York University shows that the American bumblebee (Bombus pensylvanicus) is facing extinction in Canada, putting a multitude of crops, wildflowers, trees, and shrubs at risk. This bumblebee's dramatic decline could have grave repercussions throughout the entire ecosystem.
As reported in the Journal of Insect Conservation, from 2007 to 2016 the American bumblebee's range was 70 percent smaller than it was between 1907 and 2006. But even within this reduced area, the insects are not safe. Their relative abundance has declined by 89 percent over the last decade compared to the previous century.
“This bumblebee species now has a reduced overall range,” lead author Victoria MacPhail, a graduate researcher at York University in Ontario, 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.”
In their most recent assessment, a federal advisory committee classified the species as "special concern" when determining its extinction risk. However, the researchers found the American bumblebee's threat level to be much higher, describing it as critically endangered. The team urges the advisory committee to review their decision to list the insect as special concern.
“This species is at risk of extinction and it's currently not protected in any way despite the drastic decline,” commented senior author Sheila Colla, an expert in bees and endangered species. “Now that we have assessed the extent of the decline and located where the remaining populations are, 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.”
Colla's previous work focused on a different type of bumblebee, the rusty-patched bumblebee, once commonly found in southern Ontario. This insect has not been seen in Canada for 10 years.
“The American bumblebee is still found in areas throughout its Canadian range and immediate action may save it from the same fate as the rusty-patched bumblebee,” added Colla.
The team used a combination of citizen scientists, museum specimens, and field work to estimate the extinction risk of this species.