Thermal imaging has transformed feral animal control in Australia over the past decade. For landholders who have never had a thermal operation on their property, understanding why the technology is so effective — and what it can and can’t do — helps set realistic expectations.
What Thermal Imaging Detects
Thermal (or infrared) imaging cameras detect heat radiation emitted by objects. All warm-blooded animals emit infrared radiation proportional to their body temperature — typically around 37–39°C. Against a cooler background environment (ground, vegetation, water), this heat signature creates a clear image on the operator’s scope, even in complete darkness.
Modern thermal riflescopes can clearly detect a pig at 300–400 metres under normal night conditions, depending on terrain and vegetation cover. At 100–150 metres, the animal’s shape, size and gait are clearly readable — allowing species identification and shot placement at ranges well beyond what any conventional spotlight-based system can achieve.
Why Night Operations Encounter More Animals
Feral pigs in SE Queensland are strongly nocturnal — they avoid open ground during daylight hours and typically emerge to feed and move between dusk and dawn. The same is true for foxes. Daytime visual searches of open paddocks rarely reveal the animals that are clearly visible to thermal at night on the same country.
This means that the expected encounter rate on a night thermal operation is dramatically higher than any daytime control method on the same area. Properties where a landholder has seen “one or two pigs” by day routinely have significantly larger populations moving at night.
Terrain and Vegetation
Thermal is effective across most terrain types in SE Queensland — open pasture, creek lines, dense scrub, orchard country and mixed timber all produce readable thermal signatures. The key limitation is line of sight: thermal cannot see through solid objects or dense vegetation. Animals in thick lantana or heavy scrub may not be detectable until they move into a clearing or gap.
Night operations are typically conducted from a vehicle (spotlight-style) or on foot in tighter country. The approach is adapted to the specific terrain and target species.
Thermal in Context
Thermal control is most effective when it’s part of a broader management approach — regular operations at appropriate intervals (typically 3–6 months), coordinated with neighbouring properties where pig populations span boundaries, and documented with GPS-logged reports. A single night operation delivers immediate population reduction but is not a one-time solution.