Exotic winter-flowering plants keep bees busy during cold months

An unusual rise in the number of bees in the cold winter months has been observed in the recent years, and scientists have now discovered the reason behind it.

Scientists from Queen Mary, University of London have found that while most bees are hibernating, the buff-tailed bumblebee, Bombus terrestris, is out taking advantage of exotic winter-flowering plants in the gardens and parks.

The study suggests this unique species raises an extra generation of workers to collect nectar from such plants as strawberry trees and holly-like Mahonia, which flower during the colder months.

"All of the UK's bumblebee species normally die out in the autumn leaving only their new queens to survive the cold in hibernation," said Dr Thomas Ings from Queen Mary's School of Biological and Chemical Sciences.

"However, this research points to a major new change in the behaviour of the British buff-tailed bumblebee.

"It is tempting to link the increase in winter bee activity to climate change, especially with the warmer winters we've experienced over the last two decades, but the fact that we only find winter bees foraging on exotic flowering plants in parks and gardens suggests that Britain's love of winter flowering plants plays a crucial role," he added.

According to colleague Ralph Stelzer, these winter bees might even be able to collect nectar faster than those foraging in the summer.

He monitored the bees' activity by tagging them with tiny state-of-the-art Radio Frequency Identification (RFID) chips - similar to the technology used in the Transport for London's Oyster cards system - and measuring the amount of nectar they collected.

The study has been published in the journal PLoS One.