The buzzing of bumblebees in the garden is the sound of summer. Wild bees play a valuable and often underestimated role in pollinating both agricultural crops and wild flowers. Bumblebees for example, pollinate soft fruit crops like tomatoes and sweet peppers. But with ever increasing demands on the land for agriculture and industry since the end of World War II, bee friendly forage and nesting sites have diminished. While six species of bumblebee are widespread across the UK and appear to be thriving, many species of bumblebee are in decline. Two species became extinct in the UK during the 1900s, Cullum’s bumblebee and the short-haired bumblebee (the latter is currently being reintroduced in Dungeness), and a further eight species are on conservation priority lists because of large-scale declines in their distribution. For example, the great yellow bumblebee is now only found in the far north of Scotland.
Great yellow bumblebee (Bombus distinguendus). Photo credit: Nick Owens
To monitor population declines, extinctions, and indeed population growth and re-introduction successes, we need data on the populations of each species across time and geography. Since 2010, The Bumblebee Conservation Trust (BCT) organised a citizen science project to do just that, called BeeWalk (www.bumblebeeconservation.org/beewalk/). Volunteers across the country walk their own fixed route every month between March-October, counting bees and identifying them to species and caste (queen, worker, male) level. In this way the BCT can gather long term abundance and distribution data to analyse population trends, allowing early detection of population declines in response to changes in land-use and climate change. Ultimately, these data can tell us the best way to manage the countryside for these important pollinators.
Volunteers need to learn basic bumblebee ID to take part. I was lucky enough to take part in a training day with BCT to help train up other volunteers for BeeWalk. Following that, I led a bumblebee ID and BeeWalk workshop at Paignton Zoo last summer. With only 25 bumblebees in the country, bee ID is not such a daunting task. It can be fun to start to recognise the different species and learn more about their life cycles, and I believe it helps people connect more, and thus care more, for the nature around them. With bee declines hitting the headlines there’s a lot of public interest and the workshop filled up with keen volunteers from all walks of life!
A pin collection of common UK bee species used for teaching. Photo credit: Arran Folly
We spent a few hours learning how to ID bumblebee species and castes, with the help of a presentation, pinned specimens and a live bumblebee (Bombus terrestris – buff tailed bumblebee) colony in a box. Starting with the most common species and breaking them down into groups of red-tailed, white-tailed and ginger bees, before moving on to the cuckoo bumblebees and rarer species. Castes within each species are usually different too; while workers are often smaller versions of the queens, males tend to look quite different. The best place to learn is out in the field, so on this beautifully warm sunny day we went out in search of bees in the Paignton zoo gardens, abuzz with bees foraging on pollinator-friendly flowers. We found lots of honeybees and all six of the common bumblebees, as well as assorted hoverflies and solitary bees. Back inside, we moved on to setting up transects for bee walks and recording data. We then set up a practice transect in nearby Primley Meadow, and went out to walk it and practise ID skills. It was a very enjoyable day, and I hope it encouraged some of the attendees to set up their own bee walk and contribute to this important national survey.
Bombus terrestris bee colony showing worker bees looking after brood (Photo credit: Robyn Manley)