Whilst out surveying for the Short-necked Oil Beetle (Meloe brevicollis) on the Castlemartin Range in Pembrokeshire last June, a team from the ‘Natur Am Byth!’ project led by Buglife Cymru Conservation Officer, Liam Olds, recorded an unusual buzz of activity around discarded ammunition casings on the coastal military range.
The Gold-fringed Mason Bee (Osmia aurulenta) is a specialist snail shell-nesting bee. They are often limited by the abundance and quality of available snail shells, however, at the Castlemartin Range, they appear to have found an unlikely alternative.
Female Gold-fringed Mason Bees were observed entering and exiting discarded ammunition casings with pollen. Some of the casings had already been plugged at the entrance with leaf mastic (chewed-up leaves), which the bees use to close the entrance to their nests, suggesting that the bees were raising their offspring inside these casings.
They even seemed to be choosing these casings as a nesting location, over the more expected choice of an empty snail shell.
Gold-fringed Mason Bee applying leaf mastic to a brood cell partition within a brass casing © Liam Olds
Brass ammunition casings © Liam Olds
Sandy bank at Linney Burrows, Castlemartin Range © Liam Olds
This observation demonstrates that bees with specialist nesting habits, such as the Gold-fringed Mason Bee, can take advantage of artificial nesting locations when they are made available to them and that these bees are more adaptable than previously thought.
Thank you to the survey team Liam, Anna, Cath and Cathy for sharing this discovery and to the Ministry of Defence for their ongoing interest in our work.
Liam Olds, Buglife Conservation Officer, said “It is rather remarkable that such a specialist snail shell-nesting bee is taking advantage of the availability of discarded brass ammunition casings at the Castlemartin Range, and even appears to be preferentially selecting them over the more typical empty snail shells. We look forward to working with the Ministry of Defence to monitor this population over the coming years to better understand how these bees have adapted to utilise such an artificial nesting location as this.”
The Ministry of Defence shared this message, “While personnel do try to clear up their spent casings after training, it is inevitable, given the number of rounds fired over multiple positions, that some are missed.”
If you are planning to visit Castlemartin Training Area, please make sure to follow these simple steps:
- Check live firing times on GOV.UK.
- Stick to public footpaths, bridleways, byways and Public Rights of Way.
- Take notice of red flags, red lights and signage which indicate access is prohibited.
- Never touch military debris on the ground. Report it for safe removal.
- Keep dogs under control, in sight and pick up after them.
The full article, ‘An unconventional home for Osmia aurulenta (Hymenoptera: Megachilidae)’, by Liam Olds is available here.
To learn more about the Gold-fringed Mason Bee, visit our Bug Directory.
This survey was delivered as part of the ‘Natur am Byth!’ project, a flagship conservation programme for Wales which is restoring key populations of endangered species and connecting Welsh communities with their natural heritage.
The project brings together Buglife, Plantlife, Amphibian & Reptile Trust, Bat Conservation Trust, Marine Conservation Society, Bumblebee Conservation Trust, Butterfly Conservation, RSPB, Vincent Wildlife Trust and Natural Resources Wales.
‘Natur am Byth!’ is funded by National Lottery Heritage Fund, Natural Resources Wales, Welsh Government and a number of charitable trusts, foundations and corporate donors including Esmée Fairbairn Foundation and the Banister Charitable Trust, and significant support from Welsh Government’s Landfill Disposals Tax Communities Scheme administered by Wales Council for Voluntary Action (WCVA).
Main Image Credit: Gold-fringed Mason Bee nest in discarded ammunition cases © Liam Olds
