The American Bumblebee is facing imminent extinction in Canada, according to a study led by York University published in the Journal of Insect Conservation on April 17.
The study found the species to be critically endangered, which is considered the highest and most at-risk classification before extinction. A number of bumblebee species are declining across North America and the pollinators are necessary to grow Canadian crops such as apples, tomatoes and legumes as well as many trees, shrubs and wildflowers. The researchers assessed the extinction risk of the American Bumblebee to be higher than a federal advisory committee’s most recent assessment, which placed the species’ extinction risk at special concern. Researchers found that the American Bumblebee’s area of occurrence has gone down by about 70 per cent and its relative abundance decreased by 89 per cent between 2007 and 2016 compared to 1907 to 2006.
“This species is at risk of extinction and it’s currently not protected in any way despite the drastic decline,” said assistant professor Sheila Colla, an expert in bees and endangered species in York’s Faculty of Environmental Studies, who co-authored and helped design the study. “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 has studied bumblebees in Southern Ontario since the mid-2000s. This study relies on the annual data that she and her fellow researchers have collected as well as data from Southern Ontario gathered in the citizen science program, Bumble Bee Watch, in which volunteers submit bumblebee photos through a website or phone app for experts to identify.
The team also used the Bumble Bees of North America database to obtain records of bumblebee species in Ontario and Quebec dating back to the late-1800s and their own field survey work to evaluate the status of the species within its Canadian range, using the globally-recognized International Union for the Conservation of Nature (IUCN) Red List assessment criteria. The study’s research team was led by Colla’s doctoral student Victoria MacPhail and a scientist from the University of Vermont.
“This bumblebee species now has a reduced overall range,” MacPhail said. “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 per cent decrease in overall range.”
MacPhail said the species is now a rare sighting in Toronto, adding that you’d have to catch 1,000 bumblebees to find four of the species compared to finding 37 bees in the past. The study aligns with Colla’s previous findings about the critically endangered Rusty-patched Bumblebee, which has not been seen in Canada for about 10 years and declined toward extinction without receiving protection or conservation management.
“The American bumblebee is still found in areas throughout its Canadian range,” Colla said, “and immediate action may save it from the same fate as the Rusty-patched Bumblebee.”