Bumblebees accumulate up to seven times the amount of toxic heavy metals as honeybees, even when foraging side by side, according to new research from the University of Cambridge. The metals can impair their ability to find food and reproduce, threatening colony health.
This disparity suggests bumblebee species may face disproportionate risks in polluted areas. Honeybees, by contrast, appear to pick up fewer metals, though scientists are still investigating why the difference exists.
The study provides a concrete ratio — up to 7x — by comparing heavy metal loads in bees from the same foraging grounds. Researchers say the findings highlight a hidden vulnerability among wild pollinators that routine monitoring often overlooks.
If metal contamination continues to rise, bumblebee populations could decline, affecting pollination of crops and wild plants. Conservation efforts may need to target pollution hotspots rather than assuming all bees face equal threats.
“We were surprised by the magnitude of the difference,” one researcher noted, adding that more work is needed to trace the exact source of the contamination.