After conducting an extensive study, scientists from Canada and the United States have determined that climate change is shrinking the home ranges where bumblebees and other vital pollinators are found in Europe and North America.
Termed “range compression,” researchers from the University of Vermont and University of Ottawa found that the decreasing territory bumblebees call home has corresponded with warming temperatures and that the bees are moving to higher altitudes as a response to climate change, according to the recent announcement by scientists from the University of Vermont.
The study drew on more than 420,000 historical and current records of many species of bees to confirm their declining numbers on a continental scale as well as geo-referenced databases from museum collections on both continents.
According to the announcement, with climate change, many species of animals, including butterflies, have been observed to expand their territory; the northern edge of their range marches toward the North Pole while the southern edge remains in place. Not so with bumblebees. The team of fourteen scientists who conducted the new study found that northern populations of many bumblebee species are staying put while the southern range edge is retreating away from the equator.
“This was a surprise,” Leif Richardson, a scientist at the University of Vermont who helped lead the new research and a bee expert at UVM’s Gund Institute for Ecological Economics. “The bees are losing range on their southern margin and failing to pick up territory at the northern margin — so their habitat range is shrinking.”
Over the 110 years of records that the team examined, bumblebees have lost about 185 miles (300 km) from the southern edge of their range in Europe and North America, according to the study, which was published in the journal Science.
Infographic courtesy of Ann Sanderson, Sheila Colla and Paul Galpern.
“The scale and pace of these losses are unprecedented,” said Kerr.
The situation is dangerous not just for bees and pollinators, but for the entire global community.
“Bumblebees pollinate many plants that provide food for humans and wildlife,” said Richardson. “If we don’t stop the decline in the abundance of bumblebees, we may well face higher food prices, diminished varieties, and other troubles.”
“Pollinators are vital for food security and our economy, and widespread losses of pollinators due to climate change will diminish both,” stated Jeremy Kerr, a biologist from the University of Ottawa, who led the new study. “We need to figure out how we can improve the outlook for pollinators at continental scales.”
As bee populations continue to be the subject of numerous calls for alarm — particularly in regards to pesticide use and loss of natural habitat due to human development — the researchers have suggested taking controversial action to help the bumblebees expand into new territory.
“We need new strategies to help these species cope with the effects of human-caused climate change, perhaps assisting them to shift into northern areas,” said Kerr.
“Assisted migration” may be a solution to the bee’s shrinking range, but the root of the problem remains climate change, said Kerr.
“These findings could spell trouble for many plants — including some crops, like blueberries — that depend on bumblebees for pollination,” Richardson said. “Bumblebees are crucial to our natural ecosystems.”