Thermal drones find hidden hotspots months after Cairngorms wildfire

Thermal drones are still finding heat beneath the ground in the Cairngorms three months after July's wildfire, according to a BBC report published on 10 October. On a dawn patrol, pilot Pete Short identified a hotspot beneath a tree; warm soil and smoke were found at the location. The discovery shows why land managers are continuing to check affected ground after the visible flames have gone.

Short told the BBC that a previous thermal flight had found eight hotspots. He said each location found by drone is reported to the land manager, whose teams can dig into the ground and douse it with water. The reported patrol provides a direct example of the method finding heat that was difficult to see from the surface; it does not establish how many hotspots remain across the wider fire area.

How thermal drone patrols guide ground teams

The BBC technology reporter Shiona McCallum accompanied Short on an early-morning flight. A bright area appeared on the drone's thermal image beneath a tree. At the coordinates, there was little obvious sign of fire until the ground was examined: the soil and a rock felt warm, and smoke rose after a thin layer of earth was scraped away. Short told the BBC that without thermal technology the team would be ‘totally blind’ to it.

Ben Jones, senior site manager for RSPB Abernethy, told the BBC that precise hotspot locations help direct limited staff resources. He said each hotspot has the potential to reignite a larger fire. That is a warning about what could happen, rather than a report that one of the newly detected hotspots has already done so.

When firefighters handed over the affected land

The Scottish Fire and Rescue Service says it left the scene on 17 August and handed the final affected area around RSPB Abernethy to the RSPB. Its announcement the next day said RSPB teams were continuing to dampen down hotspots. The October drone patrol therefore concerns continuing land management after that handover, rather than a claim that fire crews remain at the scene.

Access has changed in stages. The fire service's timeline says parts of Glenmore reopened to visitors from 7 August, while the Forest Lodge access road in Abernethy remained closed in its 14 August update. After the handover, the service warned that some locations could remain hazardous because of unstable ground and falling trees. The RSPB asked visitors to follow signs and stay out of affected reserve areas until they could be made safe.

Those warnings matter even where flames are no longer visible. In its handover statement, the RSPB said damaged tree roots created a risk of falling trees, including near tracks, and that heavy machinery would be used for further work where firebreaks had been created. The statement did not give a date for welcoming visitors back to the affected parts of RSPB Abernethy.

Why affected-area estimates differ

The published estimates of the wildfire's extent do not match. The BBC reports about 3,300 hectares, or 33 square kilometres, citing the Cairngorms National Park Authority. The Scottish Fire and Rescue Service estimated approximately 25 square kilometres in its 27 July update and repeated that figure in its 14 August incident timeline. The available accounts do not explain the difference, so neither figure should be presented as a reconciled final total.

The figures describe a substantial area, but they cannot by themselves show the condition of every part of it now. The fire service's timeline records phased changes to exclusion zones and access as operations progressed. Short's patrol, meanwhile, identifies specific places where heat is still detected. These are different measures: an estimate of land affected during the incident and observations of residual heat at particular locations.

What repeat drone flights may reveal

The BBC reports that Short is programming repeat drone routes using predetermined waypoints. Photographs and video captured from the same positions could show how the landscape changes over time. That monitoring is separate from the immediate work of locating heat for ground teams, and the published report does not establish the full ecological effects of the fire.

Sarah Henshall, the Cairngorms National Park Authority's head of conservation, told the BBC it was too early to determine the full ecological impact and that recovery could take years or decades. Short also said he believes rapid aerial views could help spot future fires early. That is his view of a possible use for the technology; the reporting does not demonstrate that drones have prevented a later fire.

For now, the confirmed role is narrower and practical: thermal flights can point teams towards heat beneath ground that looks quiet, and repeat images may document change. The number of remaining hotspots, the timing of safe access to affected reserve areas and the eventual ecological outcome remain unresolved in the published accounts.