In the past, bumblebees were found all over the place. Some people would find them buzzing around flowers in their yards or around the mailbox. However, since the 20th century, the effects of climate change have reduced the chances of seeing a bumblebee by over 30% on average in Europe and North America. This discovery comes from a recent study published in the journal Science.
In the study, researchers from the University of Ottawa (UO) in Canada analyzed changes in the populations of sixty-six bumblebee species across the two continents. Then, they compared the data with climate changes in those regions. Their findings revealed that as climate change causes precipitation and temperatures to increase, so does their risk for extinction.
Senior author of the study, Dr. Jeremy Kerr, said:
The things we grew up with as kids are fading away very fast. It’s not just that we’re looking at what our kids will experience; it’s that we are looking back, not even a full generation, just to when we were kids, and saying, ‘Could we take our children to places we loved and find what we found?’ What our study says is that that answer is no across entire continents.
The researchers used a database of around 550,000 records to evaluate changes in the presence and diversity of bumblebee species across Europe and North America. To estimate the distribution of the species across the two continents, they looked into two time periods, 1901 to 1974 and 2000 to 2015. Then, they examined whether the total precipitation and average monthly temperatures in the locations surpassed the bee’s tolerance level.
Across both continents, the researchers found rapid and widespread declines in bumblebee populations. Between 2000 and 2015, the odds of finding bumblebees in the areas studied dropped by 17% in Europe and 46% in North America compared to the 1900s time period.
Bumblebees prefer slightly moist, colder climates in which there’s a variation in seasons. Declines in their populations are linked with increasing warmer temperatures and habitats drying out, which diminishes bumblebees’ chances of colonizing a new home and creating more species.
Dr. Kerr explained:
Colonization is when an animal goes to a new place, and there was no population of that animal there before, and it establishes a new population. If that’s happening a lot, then the species might be doing okay. The amount of local extinctions we saw was eight times more common than these colonization events. Climate change is making these species disappear at a rate they couldn’t keep up with at all to replace themselves.
During the periods, the authors analyzed, the climate across Europe and the US changed dramatically due to human activity. Over the past few hundred years, we have warmed the planet up to 1.3 degrees Celsius, which is nearly the “1.5-degree critical warming threshold.”
The loss of bumblebees can lead to the following:
- Decreased biodiversity
- Impairment of ecosystem services
- Effected food and water supply
- Reduced control of climate and disease
- Impairment of supporting nutrient cycles and oxygen production
Peter Soroye, co-author of the study, said:
Bumblebees are among the best pollinators we have in the wildlife system. They’re out for really long periods of the year in a lot of different weather conditions, and they visit a really broad range of flowers. They’re really a critical piece of these natural landscapes that we like to enjoy.
Bumblebees pollinate all kinds of delicious plants, including blueberries, cucumbers, melons, tomatoes, squash, and more. Listed below are ways we can help the declining bee population and see that they survive climate change:
- Reducing the use of pesticides;
- Planting a diverse array of shrubs and flowers;
- Making a ‘bee waterer’
- Providing them with shelter from the sun and extreme weather events;
- Building them a bee hotel.
