Research conducted by a team from Lund University has revealed that an increase in honeybee populations negatively impacts wild bumblebees in Ireland’s Wicklow Mountains. As honeybees are introduced to these flower-rich heathlands, their presence alters the behavior and physical size of the native bumblebee populations.
The study, published on December 10, 2025, in the journal Proceedings of the Royal Society B: Biological Sciences, involved tracking bumblebee activity across areas with varying numbers of honeybee hives, ranging from zero to thirty-five. The researchers observed significant changes in bumblebee behavior as honeybee populations increased, indicating that their foraging efficiency decreased.
Behavioral Changes in Bumblebees
According to Lina Herbertsson, a biology researcher at Lund University, the bumblebees adapted quickly to the presence of honeybees. The study found that bumblebees spent less time foraging on heather flowers, prompting them to move on more rapidly. This behavior suggests a reduction in available nectar and pollen, which are crucial for their survival.
The study’s findings also indicated that bumblebees in areas with higher honeybee densities were smaller in size. This size reduction may be attributed to larger bumblebees, which typically venture further from their nests, relocating to areas with fewer honeybees, while smaller bumblebees remained closer to the hive to assist with foraging duties.
Herbertsson noted, “This is not something we expect in places that are absolutely teeming with flowers. The effect was noticeable both near the beehives and up to a kilometer away.”
Implications for Pollinators and Agriculture
The implications of this research extend beyond Ireland’s boundaries. Honeybees, bumblebees, and other wild bee species are essential for the pollination of various crops, wild plants, and fruits. With wild pollinators already facing pressures from habitat loss, the growing number of honeybees compounds the challenge of ensuring adequate resources for all pollinator species.
Beekeeping plays a vital role in cultural traditions and food production, creating a need for careful management of honeybee populations to support the coexistence of both honeybees and wild bumblebees. Herbertsson emphasized the importance of these findings, stating, “We hope our results can help beekeepers and conservation biologists plan beehive placement so that both honeybees and wild bumblebees can thrive. Ultimately, we want to preserve all pollinators, something that is essential for both farming and wild ecosystems.”
The study underscores the delicate balance required to maintain healthy ecosystems and sustainable agriculture, highlighting the need for collaborative efforts between beekeepers and conservationists.