Alarming data shows it’s time to save the bees.
By Molly Glick February 7,
2020
Within just one human
generation, the odds for bumble bee survival have dropped by an average of more
than 30 percent, according to a new study.
As global temperatures rise
and precipitation rates grow more extreme, bumble bees are likely to have
trouble adapting to their environments. Additionally, expected heatwaves and
droughts will create super dry environments, which could harm the flowers that
the insects depend on for food.
European bumble bee
survival rates fell by an average of 17 percent between 1975 and 2000, while
North American ones dropped by about 46 percent over the same period, according
to the recent research published this week in Science.
Researchers from the
University of Ottawa created a model to estimate the likelihood of bumble bee
decline among 66 different species found throughout North America and Europe:
the projections incorporate each species’ individual temperature and
precipitation tolerances, which are now increasingly challenged by a warming
planet.
The team calculated the
fall in survival rates during a gap between the 20th- and 21st-century
population data sets–and the results aren’t too optimistic. Such rates align with
a mass extinction, the study claims, suggesting possible disappearance within a
few decades.
“Many people who liked to
run around in fields or forests when they were young and look for bees and
other bugs would now see many less of these critters if they were to go looking
now,” says study author Peter Soroye, a PhD student in the Department of
Biology at the University of Ottawa.
Their projections also
suggest that previous
reports of climate change-driven bumble bee declines may be too
conservative, particularly for European species.
The team noted how more
frequent high temperatures hurt a species’ ability to colonize new areas and
heightens local extinction risk; though scientists don’t know why exactly this happens, heat likely
strains a bee’s metabolism and food sources. Therefore, species living in areas
with more dramatic temperature spikes are especially vulnerable.
Just as all of nature
faces unprecedented extinction threats—particularly insects
as a whole—the model could forecast biodiversity loss for other organisms
of interest.
Bumble bees are large and
furry as an adaptation to cold climates, says Dave Goulson, an ecologist at the
University of Sussex who studies bumble bee ecology and conservation research.
Unlike most insects, they thrive in cooler, more temperate regions and live
more rarely in warmer areas where they tend to overheat; therefore, they’re not
particularly prepared for a heating planet.
Besides surging climate
hazards, bees also suffer from direct human actions like pesticide use and
agricultural intensification. Neonicotinoid pesticides, research shows, shorten a bumble bee’s flight and
potentially hinder pollination.
Humans need bumble bees:
They’re the best wild landscape pollinators and the most effective insects in pollinating crops like
squash, tomatoes, and berries. Insect pollinators like bees facilitate the
growth of 35 percent of global crops.
“Our results show that we
face a future with many less bumble bees and much less diversity, both in the
outdoors and on our plates," Soroye says.
On a positive note, the
team predicts that bumble bee populations could grow where climate change
shifts temperatures within species’ tolerances; for example, some Scandinavian
bees are moving north of the Arctic Circle. Going forward,
bee conservation efforts depend on public awareness, which has grown in
recent years. Still, most people don’t fully understand the threats bees face.
The issue caught widespread
attention in 2017 as German researchers highlighted the recent dramatic drop in flying insect
populations, including bees; before that study, few people had considered the
climate’s threat to insects, Goulson says. He thinks the issue still demands
greater publicity.
“My impression is
that most people have still not grasped the gravity of the environmental
situation, and the consequences things like insect decline will have for all of
us,” he says.
No comments:
Post a Comment