Hidden Athletes: UK’s Rarest Beetles Take Nightly Marathons in Temperate Rainforests

A new study has uncovered the adventurous and athletic lifestyles of one of the UK’s rarest beetles.

The blue ground beetle, confined mostly to temperate rainforest fragments in south-west England, has been found to travel the scaled-up equivalent of several kilometres a night in search of food and mates. This remarkable finding sheds light on the beetle’s behaviour and habitat preferences, providing crucial insights for conservation efforts.

The Elusive Blue Ground Beetle

The blue ground beetle is one of the largest and rarest species of ground beetle in the UK, with a very restricted distribution, mostly found on Dartmoor. Despite its size and rarity, little was known about its biology until now. Dr Nick Royle of the University of Exeter, leading the study with PhD researcher Brogan Pett, emphasises the importance of understanding the beetle’s habitat use and essential characteristics for thriving.

Tracking Beetle Movements

In collaboration with the Woodland Trust, scientists have been using unique ‘beetle backpacks’—miniature radio trackers—to monitor the daily movements of 36 beetles in Dartmoor National Park. The study revealed that some beetles are more active and adventurous than others, with certain individuals travelling extensive distances each night. One particularly athletic beetle, tagged R9, was likened to the footballer Ronaldo for its impressive nightly journeys.

“Individuals varied considerably in how active they were,” Brogan Pett explained. “Our radio-tracking revealed that they also prefer to stay away from the outside border of their woodland habitat, with individuals resting up during the day in mossy logs of decaying deadwood or in cracks in trees in shady parts of the forest.”

Habitat Preferences and Conservation Implications

The study highlighted the beetles’ preference for old growth temperate rainforest, rich in decaying deadwood and prey. This information is invaluable for the Woodland Trust, which manages several rainforests across south-west England. Sam Manning, the site manager of Bovey Valley Woods, noted that the data will inform vital decisions about rainforest management and restoration.

“Blue ground beetles are an important indicator of a healthy rainforest here in the southwest,” Sam said. “The research has already shown that blue ground beetles prefer occupying areas with old growth temperate rainforest characteristics.”

A Call for Action

Temperate rainforests, also known as Atlantic woodlands, are incredibly rare in the UK, mainly found on the west coast. These habitats are characterised by ancient oak, birch, ash, pine, and hazel woodlands, along with diverse features like open glades, boulders, crags, ravines, and river gorges. The Woodland Trust is working with partners in south-west England, Scotland, and Wales to form alliances to protect these unique environments.

With the general election approaching, the Woodland Trust is urging the new Government to develop a Trees Action Plan for England. This plan would include restoring native trees and woods to good ecological condition, ensuring the protection and resilience of these vital habitats.

The full analysis of the beetle findings is expected in the autumn, providing further insights into the blue ground beetle’s fascinating lifestyle and informing future conservation efforts.

For more on rainforests and their conservation, visit the Woodland Trust’s website.