East Anglian beetles shed light on UK climate 4,000 years ago

Linda Geddes
·3-min read

Rarely is finding a pair of wood-eating beetles in a dusty cabinet a cause for celebration. But when Natural History Museum curator Max Barclay chanced upon the dead insects, in one of the museum’s specimen drawers, he spotted an opportunity to solve a decades-old mystery: why a pair of foreign beetles had been submerged in an East Anglian bog. The answer sheds light on the state of the UK’s climate almost 4,000 years ago.

The beetles were donated to the collection in the 1970s, by an East Anglian farmer who found them inside a piece of old wood he had dug up in one of his fields, and was splitting for firewood. Alarmed by their size, and curved long, threadlike antennae, and concerned that his farm might be infested with wood-boring insects, he contacted the museum for advice.

Recognising them as long-dead Oak Capricorn Beetles – a non-native species, usually found in southern France and Hungary – a museum scientist reassured the farmer that they were unlikely to pose a current threat, and filed both wood and insects away for future investigation.

Rediscovering the beetles more than 40 years later – and with access to new technology that allows biological material to be accurately dated – Barclay sent samples of beetle tissue and wood away for analysis.

The results shocked him. “It’s come back that these things are more than 3,800 years old, which is breathtaking,” he said.

Very little biological material exists from this period, with the exception of a few mummified human remains recovered from peat bogs in Ireland and elsewhere. These are the beetle equivalent of such “bog bodies”, which makes them extremely rare. “You have a few beetles that were preserved inside the Egyptian pyramids, but the pyramids are very dry and protected from pests. You don’t expect something to survive for this long in a swamp in the east of England,” Barclay said.

“These beetles are older than the Tudors, older than the Roman occupation of Britain, even older than the Roman empire. They were alive and chewing the inside of that piece of wood when the pharaohs were building the pyramids. It is tremendously exciting.”

The discovery, which features in the next episode of Natural History Museum: World of Wonder, airing on Thursday at 8pm on Channel 5, also provides fresh insights into the UK’s climate during the bronze age.

Rather than being an invasive species, Barclay suspects these beetles may once have been endemic in the British Isles.

“Usually we find these beetles about halfway down France, and in other countries just north of the Mediterranean, so it suggests that the climate was a little bit warmer,” Barclay said. “Also, if you think of the east of England now, you don’t think of there being forests of big trees, so these areas were deforested – probably by people.”

With around 10m dead beetles in about 22,000 drawers, it’s possible there may be further prehistoric insights in the British Isles loitering undiscovered in the museum’s cabinets.

Barclay said: “Sometimes the museum’s collection gives you a time capsule into what these places were like before we were there, which you can’t get any other way. It’s a kind of a contemporary fossil record.”