The Strain of Heat on Our Vital Pollinators: A Closer Look at Bees in a Changing Climate

WILLIAMSPORT, Ohio (AP) — As Isaac Barnes, a beekeeper, toils under the sweltering sun, sweat beads form on his forehead beneath the protective veil. The late morning June heat feels almost sauna-like, as he moves boxes of honeycomb from his hives to his truck.

While Barnes grapples with the heat, his honeybees endure even warmer conditions. Their body temperatures can soar to 27 degrees Fahrenheit (about 15 Celsius) above the ambient air temperature. As global temperatures rise due to climate change, scientists are striving to gauge the impact on both managed and wild bees, pivotal players in the pollination of crops, nectar collection, honey production, and reproduction.

Bees’ Adaptive Strategies Under Heat Stress

Recent studies highlight that bees adapt to extreme heat by altering their flight patterns, using less frequent but more forceful wingbeats on scorching days to regulate their body temperature. They have also been observed retreating to cooler environments, similar to how humans seek shade to escape heat stress.

“Just like we go into the shade, or we sweat or we might work less hard, bees actually do the exact same thing to avoid the heat,” explained Jon Harrison, an environmental physiologist at Arizona State University and a co-author of a significant study on bee behavior.

However, this adaptation comes at a cost. According to Kevin McCluney, a biology professor at Bowling Green State University, these alterations impact the bees’ essential activities. “They’re not going out and getting more nectar. They’re not mating. They’re not doing the things that bees would otherwise do,” he noted.

The Multifaceted Threats Facing Bees

While many bee species are naturally heat-tolerant, the increasing temperatures pose significant challenges. Scientists warn that the combined effects of climate change, habitat loss, pesticide exposure, and disease could exacerbate the decline in bee populations and other crucial pollinators.

“If you’re not well-fed, and your body is intoxicated with pesticides and you have lots of diseases in your body, you’re going to be less heat-tolerant than if you were healthy,” stated Margarita López-Uribe, a pollinator health expert at Pennsylvania State University.

Recent findings from the annual U.S. Beekeeping Survey revealed an alarming trend: beekeepers reported losing nearly 56% of their managed colonies, marking the highest loss since the survey’s inception in 2010.

Given that most managed honeybee colonies in the U.S. are vital for pollinating high-value crops such as almonds, apples, cherries, and blueberries, the decline in pollinator populations threatens food production, leading to potentially lower yields.

Challenges at Honeyrun Farms

In Ohio, Barnes operates Honeyrun Farm alongside his wife, Jayne, managing approximately 500 honeybee hives. The extreme heat presents ongoing challenges, particularly in combatting parasitic mites that jeopardize bee health. High temperatures hinder the application of formic acid, an organic solution that kills mites, due to the risk of harming bees when conditions are too hot.

“Dead hives aren’t pollinating the almonds,” Barnes lamented, reflecting on the ripple effects that stem from summer heat. Last year, they lost nearly a third of the 400 hives they sent to California for almond pollination, likely due to pre-existing health issues exacerbated by summer heat stress.

Despite some advantages—such as a bumper honey crop spurred by soybeans blooming in hot weather—Barnes acknowledges the long-term consequences of diminished forage diversity in a landscape largely dominated by corn and soybeans. Erratic blooming patterns of native flora, such as goldenrod, make it increasingly difficult for bees to find sufficient food.

Research at Risk: The Future of Pollinator Studies

Only in recent years has the severe decline in global pollinators garnered attention, and data on the role of climate change in this decline remains limited. “It’s a relatively new focus for biology,” Harrison elaborated, emphasizing the importance of continued research.

Unfortunately, funding for critical bee research is in jeopardy, particularly as proposed budgets threaten to eliminate essential programs like the USGS Bee Lab. U.S. Senator Jeff Merkley from Oregon has expressed concern over this issue, highlighting the crucial role pollinators play in sustaining both ecosystems and agriculture.

“Rather than taking bold action to protect them, the proposed budget would zero out funding for essential research aimed at saving important pollinators,” he stated in a press release.

As research efforts face potential cuts, Harrison warns that halting studies on bee biodiversity and health could have dire consequences, increasing the risk of scarcity and rising prices for fruits, vegetables, nuts, coffee, and chocolate. “Hopefully, even if such research is defunded in the U.S., it will continue elsewhere, preventing extreme scenarios,” he concluded.