Buzz Pollination: A Hidden Energy Drain for Bumblebees

A study published by the Royal Society has revealed that the energy bumblebees expend during floral sonication—commonly known as "buzz pollination"—is comparable to the energy required for a flight take-off. This marks the first time researchers have directly measured the energy cost of this behavior.

"The metabolic rate of a buzzing bee is more than 30 times its resting metabolism, making it one of the most energetically demanding behaviors."

Key Findings

A single buzzing event requires about the same energy as a flight take-off. Since buzzing can last longer, the total energy drain on the bee may be even greater than that of a single take-off.

After buzzing, bees enter a grooming and pollen-packing phase. This is followed by a high-power take-off with a heavier load, creating a demanding two-phase sequence that was previously underestimated.

These findings challenge the long-held assumption that flight dominates bee energy budgets. Floral buzzing may represent a major, previously overlooked component of a bee's daily energy expenditure.

Statements from Researchers

Natacha Rossi, a research fellow at the University of Sussex and lead author, warned that changes in nectar availability—driven by climate change or habitat loss—could influence bee foraging behavior and, in turn, which plants they pollinate.

Dr. Beth Nicholls, principal research fellow at the University of Sussex, stated that bees must now choose flowers carefully to ensure they have sufficient energy for pollination.

Prof. Mario Vallejo-Marin, at Uppsala University, noted that while it was long suspected buzz pollination was energetically expensive, the study now allows for quantitative predictions of how this behavior could affect ecology and evolution.

Background on Bumblebee Populations

The study highlights troubling population trends. In 2024, UK bumblebee numbers declined by almost a quarter compared to the 2010–2023 average, according to the Bumblebee Conservation Trust. Researchers attributed this to cold and wet spring conditions.

"Despite a 2025 rebound, many species remain below average."

The researchers warned that declining nectar supplies—resulting from the climate crisis and habitat destruction—could further intensify the strain on these essential pollinators.