Thermal drones hunt underground fires in Scotland’s Cairngorms

Three months after a devastating wildfire swept through Scotland’s Cairngorms National Park, a dedicated team of drone pilots continues a daily dawn patrol to locate smoldering hotspots hidden beneath the earth. The operation began in July when flames consumed approximately 3,300 hectares—roughly 33 square kilometers—of the landscape.

Pete Short, a senior drone pilot, operates in the affected woodland to detect residual heat that remains invisible to the naked eye. During a recent patrol, his thermal imaging equipment identified a white glow beneath a tree canopy, revealing active heat sources still burning underground. Upon investigation, the soil and rocks were found to be warm, with smoke rising after the top layer of earth was scraped away.

“Without the thermal technology we would be totally blind to this,” Short stated, noting that on his most recent flight alone, eight distinct hotspots were detected. Each coordinate identified by the drones is reported to land managers, who dispatch ground teams to excavate and douse the areas with water.

Ben Jones, the RSPB’s senior site manager at Abernethy, emphasized the critical nature of this precision targeting. With limited personnel and resources, the organization cannot survey every acre manually. He warned that even with the arrival of colder, wetter weather, these lingering pockets of heat retain the potential to reignite into larger conflagrations if left unchecked.

The environmental impact of the fire is still unfolding. While the forest floor shows signs of char and blackened trunks, early signs of ecological recovery are already visible, including green shoots, fungi, and wildflowers emerging from the ash. Dr. Sarah Henshall, head of conservation at the Cairngorms National Park Authority, cautioned that full recovery could take decades or even centuries, varying significantly across different species and zones.

Beyond immediate firefighting support, the drones are being repurposed for long-term ecological monitoring. Short is programming the aircraft to follow identical flight paths repeatedly, capturing photographs and video from consistent vantage points. This standardized data collection will allow scientists to track vegetation regrowth and landscape changes over time.

Henshall noted that the aerial perspective could also prove vital for future prevention, providing a rapid view above the tree canopy to identify potential fires before they spread. As the forest begins to show its first signs of life above ground, ground teams remain focused on extinguishing the last remnants of the blaze below.