When honeybees are introduced to Ireland’s Wicklow Mountains, they significantly impact local bumblebee populations. A recent study conducted by an Irish-Swedish research team from Lund University reveals that the presence of honeybees alters the behaviour and physical characteristics of wild bumblebees. Published in the Proceedings of the Royal Society B: Biological Sciences, the study highlights the ecological ramifications of beekeeping practices.
The research team observed sites with varying numbers of honeybee hives, ranging from 0 to 35, over several weeks. They tracked the movement patterns of bumblebees, documenting changes in their foraging behaviour. According to Lina Herbertsson, a biology researcher at Lund University, “We saw that the bumblebees adapted quite quickly once the honeybees were moved in.”
Behavioural Changes and Physical Impacts
The findings indicate that bumblebees spent less time on heather flowers, which are crucial for their foraging. This shift suggests a reduction in the availability of nectar and pollen due to competition with honeybees. Notably, the researchers discovered that bumblebees in areas with more honeybee hives were smaller in size. This size reduction may result from larger bumblebees flying to regions with fewer honeybees, while smaller bumblebees, typically responsible for brood care, took on foraging responsibilities when larger bees could not keep pace.
“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,” Herbertsson explained. The implications of these changes extend beyond individual species, highlighting the intricate relationships within ecosystems.
Implications for Pollination and Biodiversity
The research underscores a broader concern for pollinator health. Honeybees, bumblebees, and other wild bee species play essential roles in pollinating not only wild plants but also crops such as fruits and berries. With wild pollinators already facing pressures from diminishing flower-rich habitats, the addition of honeybee hives exacerbates competition for resources.
The balance between beekeeping—a cultural tradition and vital component of food production—and the conservation of wild bee populations presents a significant challenge. “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,” concluded Herbertsson.
The study emphasizes the need for careful management of bee populations to ensure the sustainability of pollination services critical to both agricultural productivity and ecological balance.
