Bumblebees are struggling to survive in our warming world and some species could soon face extinction, a critical new study says.
While other creatures are expanding northward, where it used to be too cold for them, bumblebee species in North America and in Europe are failing to migrate, the study says. Bumblebees’ habitat is also shrinking in the south — both in North America and in Europe.
“This is some of the first evidence that shows very significant effect of human-caused climate change on pollinator losses across continents,” said Jeremy Kerr, professor of biology at the University of Ottawa, and lead author of the study.
“What we are seeing is rapid range collapses in many of these species. It means we don’t have long before these species could disappear.”
The study, the most comprehensive ever conducted on impacts of climate change on pollinators, was released Thursday in Science.
Researchers compiled data on 67 bumblebee species in North America and Europe from 1901 to 2010 and studied their movement northward. The bees did not shift their ranges north and their populations disappeared from southernmost and hottest parts of their ranges.
These bee species have lost about 300 kilometres from the southern edge of their range in the two continents, researchers found.
It isn’t clear, yet, why bumblebees aren’t able to migrate.
“For an organism to colonize a place it has never lived (in) before, it’s got to move there, establish a population and then grow that population fast enough so that it survives,” said Kerr.
The loss of bumblebees could have multiple, severe consequences for ecosystems and for agriculture.
Bumblebees are, perhaps, the most fascinating of all bee species: they’re fuzzy, colourful and they are not aggressive. They’re important pollinators. More than 50 species of North American bumblebees pollinate plants, which produce flowers and seeds that feed everything from birds to bears. Bumblebees are also vital pollinators for cherries, clover, blueberries and even tomatoes.
The study is important because it reinforces the understanding that species will not all be able to just shift their range to adapt to climate change, said Sacha Vignieri, an editor with journal Science.
This research provides insight into “further potential stresses to the bee populations that are already generally declining and under significant threat,” she said.
Bees have been in headlines for months in North America — mostly because of neonicotinoid, the pesticide blamed by experts for hindering the ability of bees to navigate, feed or even reproduce.
This study emphasized that it found no evidence to dispute that neonicotinoids are harmful to bees. Bumblebee disappearances from warm, southern areas are just as likely when there is no pesticide use and little agriculture, it said.
“There is evidence that neonicotinoid kill bees — we have no evidence to suggest that is untrue,” said Kerr. “I want to be very clear on that.”
Ontario became the first jurisdiction in North America on July 1 to start reducing the number of acres planted with neonicotinoid-coated corn and soybean seeds.
Kerr, meanwhile, said it is still possible to save the bumblebee species from extinction — by the way of assisted migration.
But he stressed that it isn’t “something we can spend the next decade talking about and not do. We have to seriously consider it in the short term if we want to help these species — we are not talking a hundred years but maybe 30 years. We have to intervene . . . we have no business causing species to go extinct.”