Bees’ Floral Buzzing as Exhausting as Flight Take-off, Study Finds

A new study reveals that bees expend as much energy collecting pollen through “floral buzzing” as they do during flight take-off, highlighting a previously overlooked drain on their daily energy budget.

Scientists found that the vibrations bumblebees produce to shake pollen loose from flowers rank among their most exhausting behaviors, forcing them to “carefully choose” which blooms are worth visiting to conserve energy.

The research, published Monday by the Royal Society, is the first to directly measure the energy cost of floral sonication, also known as “buzz pollination.”

Natacha Rossi, a research fellow at the University of Sussex who led the study, said: “As nectar availability shifts due to climate change or habitat loss, the energetic demands of pollination could influence bee behavior and, ultimately, where bees forage and which plants they pollinate.”

Rossi added: “These results help us to better understand plant-pollinator relationships and just how hard at work a buzzing bee really is.”

In 2024, the number of bumblebees in the United Kingdom declined by nearly a quarter compared with the 2010-2023 average, according to the Bumblebee Conservation Trust.

Researchers attributed the drop to cold and wet spring conditions in the UK that year, and despite a rebound in 2025, many species remain below their historical averages.

Using lasers and respirometry equipment to monitor three colonies of buff-tailed bumblebees, the team discovered that a single buzzing event requires about the same amount of energy as a flight take-off.

Because buzzing episodes can last longer than take-off, the total energy drain on the bees can be even greater, the study found.

Dr. Beth Nicholls, principal research fellow at the University of Sussex, said: “The findings suggest that floral buzzing could represent a major part of a bee’s daily energy budget, something that has previously been overlooked.”

Nicholls continued: “These bees must carefully choose which flowers they visit to ensure they have enough energy to pollinate.”

The research challenges the common assumption that flight dominates bee energy budgets, the authors wrote.

The metabolic rate of a floral buzzing bee is more than 30 times higher than its resting metabolism, making the process among its most energetically demanding behaviors, according to the study.

The researchers warned that declining nectar supplies caused by the climate crisis and habitat destruction could intensify the strain on pollinators.

Professor Mario Vallejo-Marin at Uppsala University said: “We long suspected that buzz pollination was an energetically expensive affair. We can now put a number to it and begin making quantitative predictions of how it could affect the ecology and evolution of bees and buzz-pollinated flowers.”

The energetic drain does not stop when pollination ends, the study notes. After vibrating pollen loose, bees must engage in a “grooming and pollen-packing phase,” which consumes additional energy, followed by a high-power take-off to carry their heavier load — making the entire process a demanding two-phase sequence.