Thermal drones map wildlife for East West Rail works

East West Rail is using thermal-imaging drones in pre-construction ecological surveys linked to archaeological trenching. Its thermal camera is being used by East West Rail and contractor Kier to scan larger parcels for nests and animals before clearance begins — a survey that can reportedly cover a site in two to three hours.

The images have made otherwise difficult signs easier to locate. EWR says the work has identified ground-nesting skylarks, a crow’s nest high in the woodland canopy and adult birds feeding young, alongside brown hares, rabbits and rabbit warrens. Other species, including woodlark and lapwing, could also be located.

The mechanism is simple: thermal imaging highlights warmer objects against a cooler background. But the result is not automatic. Ambient temperature, time of day, vegetation cover and sensor resolution all affect performance, so qualified drone operators and Ecological Clerks of Works are needed to interpret detections and reduce false positives or missed animals.

And concretely? Earlier information lets contractors map sensitive zones, clear vegetation only where appropriate and set buffer areas, while unaffected parts of a site can continue. EWR says the approach offers greater certainty during the March–August bird-nesting season and can reduce stand-downs and reprogramming — especially when excavation windows are constrained by ground-nesting birds.

The drones remain one part of a wider mitigation process. Ecological specialists still supervise critical stages, carry out post-clearance verification and monitor retained buffers. Findings may also trigger ground checks, hand-searching, licences or timing restrictions for protected species; drone operations must additionally manage risks to people and machinery and follow Civil Aviation Authority rules.