The Lost Honeybees of Blenheim
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Britain’s Blenheim Palace is a massive country house located in Woodstock, Oxfordshire, and one of Britain’s largest homes. Built between 1705 and 1722, it achieved the coveted designation of a UNESCO World Heritage Site in 1987. It is the seat of the Dukes of Marlborough and is most famously associated with Sir Winston Churchill, for whom it was both birthplace and ancestral home.
Blenheim holds another distinction. Its estate of 6,000 acres contains Europe’s largest ancient oak forest, and in 2021 a marvelous thing was discovered: wild honeybees. And not just any honeybees. These bees are their own subspecies (ecotype), specifically adapted to these ancient woodlands. Even more, they are the wild heirs and last surviving descendants of Britain’s native honeybee population, long since thought to be wiped out by disease and invasive species. They are believed to have a pure lineage back to the times of the British Black Bee. This makes them astoundingly rare.
The oaks found on the Blenheim estate are between 400 and 1,000 years old, and are the remnants of a medieval hunting preserve of ancient kings. Because of its royal designation, no one was allowed to harvest wood. As a result, the trees — and the bees — flourished in this isolated environment.
Since the layout of the forest is essentially frozen in time, the bees’ foraging patterns have been remarkably consistent, isolated, and exceptionally adapted to the local setting.
When the bees were first recognized, at first it was thought there was only one wild hive on the estate. But when this speculation was made in the presence of a man named Filipe Salbany, he casually disagreed. “Oh, I bet I could find more.”
Salbany is an internationally renowned bee conservationist and expert who has worked with bees on three continents. Among his many talents are bee-lining and tree climbing (no small task, considering some hives are 60 feet up). Within short order, Salbany found dozens of colonies of wild honeybees on the Blenheim state, with many more areas still to explore. He started photographing the inside of the colonies by jamming his cell phone inside, but has since graduated to an endoscope.
What makes the Blenheim bees unique? Their DNA is being tested to confirm the purity of their line, but it’s not hard to pick them out in a crowd. Blenheim bees are smaller, furrier, and darker than their domestic counterparts, with less banding. The wild colonies produce small swarms (about 5,000 individuals). Interestingly, these swarms contain multiple queens — up to nine, in one case — which is more characteristic of African honeybees than European. Blenheim bees don’t store much honey over the winter, and this counterintuitive behavior doesn’t seem to adversely affect the health of the colony. Additionally, their wings are smaller and have distinctive veins, very different from imported bees. Blenheim bees also forage in temperatures as low as 39 degrees Fahrenheit (most bees stop flying below 53 degrees F).
Interestingly, Blenheim bees don’t seem to “recognize” hive boxes as suitable homes. Feral versions of domestic bees have been selected to build on flat sheets (as someone put it, “Managed bees tend to recognize hives as homes”), but not the Blenheim bees. Their preference is the hollow places in oak trees, although beech and cedar will do in a pinch. The tree cavities they prefer are about a quarter the size of a commercial beehive with an entrance less than two inches, and very high off the ground (45 to 60 feet), which are among the reasons it took so long to discover them. Within these cavities, the comb-building pattern is ideal for tree hollows, offering the Blenheim bees maximum defense and climate control.
Another interesting aspect of the Blenheim bees is their reaction to the dreaded Varroa mite. Salbany says, “These bees are quite unique in that they live in nests in very small cavities, as bees have for millions of years, and they have the ability to live with disease. They have had no treatment for the Varroa mite — yet they’re not dying off.”
This seeming tolerance of the Varroa mite does not, however, make Blenheim bees immune to numerous factors that could disrupt, dilute, or kill off their colonies.
One of the concerns is the proximity of commercial hives, which could jeopardize the genetic purity of the Blenheim colonies. There are no managed hives on the Blenheim estate, and the grounds are large enough that the Blenheim bees are fairly isolated from nearby commercial colonies. There are been attempts by local beekeepers to set up Buckfast hives around the perimeter of the estate, which could jeopardize the purity of the Blenheim bees, but Salbany uses barrier (bait) hives to intercept any swarms from these imported bees before they contaminate the gene line.
Additionally, Salbany points out how the damp and humid valleys form physical barriers to imported honeybees. He says “It’s a closed environment, in terms of bee access.”
The Blenheim bees seem to have reached a steady carrying capacity. Salbany notes, “For the 50 honeybee colonies that we have found, we probably have 500 empty sites for them to swarm into. They do not populate every single site: they’ve reached an equilibrium with their environment.”
Salbany finds the bees are extremely relaxed — enough that he does not require any protective gear when working with them. This relaxed attitude extends even to colonies in close proximity to each other … and with wasps. The insects seem to have enough forage available that no competition or (in the case of wasps) raiding occurs.
The discovery of the Blenheim bees is remarkable. Because of their unique heritage, efforts are being made to preserve them. According to one online forum, Salbany delayed announcing his discovery of the bees until he was certain they would be safe from conventional beekeepers, who often decimate any wild colonies they find.
The Blenheim estate is, in many respects, a time capsule within British agriculture, and the bees within it are highly adapted to the local forage rhythms (agricultural records from a century ago confirm this). The discovery of the Blenheim bees is both astounding and encouraging.
Originally published in the Spring 2023 issue of Backyard Beekeeping and regularly vetted for accuracy.