Two Ways to See What You Cannot
You cannot manage what you cannot see, and most feral animals go out of their way not to be seen. Two technologies have changed that for NSW landholders: thermal-equipped drones and trail cameras. They are often talked about as if you have to choose between them, but that is the wrong way to look at it. They see your property in completely different ways, and the smartest monitoring uses both.
A thermal drone is a survey: a broad snapshot of the whole property at a single point in time. A trail camera is a watch: a continuous record of one fixed spot over days and weeks. Understanding that difference is the key to choosing the right tool, or, more often, combining them.
At a Glance
| Factor | Thermal drone survey | Trail cameras |
|---|---|---|
| What it gives you | A broad snapshot: count and map the whole property at once | A continuous record: what passes a fixed point over time |
| Best question answered | How many, and where, right now? | What uses this spot, and when, over weeks? |
| Coverage | Hundreds of acres in a session, including rough country | One point per camera |
| Time dimension | A single session | Continuous, day and night |
| Ideal use | Population counts, pre-operation recon, post-operation check | Movement patterns, bait and trap monitoring, before and after over time |
| Main limits | Needs cool conditions and open country; CASA rules | Sees only where it is placed; needs power and coverage |
| Cost model | One-off or periodic survey | Ongoing per-camera monitoring |
Thermal Drones: The Snapshot and the Count
Every warm animal radiates heat that a thermal sensor sees as a bright shape against cooler ground, even in complete darkness. Flown on a grid over your property, a thermal drone turns that into a count and a map: a cluster of bright signatures on a creek flat is a mob of pigs, a lone dot on a ridge is a fox. In a single session it can cover country that would take days to walk, and reach gullies and scrub you cannot easily get into. That makes it the tool for a fast population estimate, for finding animals before a control operation, and for checking the knockdown afterwards.
What the research shows
The Australian evidence is strong. Research led by NSW DPI and the University of New England found that thermal detection roughly doubled the culling rate compared with visual observation, and picked up animals ground observers missed: 72 percent of pigs and 53 percent of deer were first detected in dense canopy. On the Hay Plains in NSW, a thermal operator found more animals, 533, than visual observers did, 302, over the same ground. Work by the University of Melbourne found a single thermal drone survey covered roughly ten times the area a spotlighting team could cover in the same time. Government programmes rely on the same principle: NSW Local Land Services used annual helicopter-mounted infrared surveys in the Western Riverina to set feral pig density baselines and measure control, part of a project that removed more than 62,000 pigs from 2016 to 2024.
When thermal does not work
Thermal is powerful, but it is conditional, and an honest operator tells you so. It depends on a temperature difference between the animal and the background, so it struggles when that gap shrinks. In hot weather, as the ground warms towards body temperature, animals stop standing out, and a Queensland study found thermal gave no advantage over visual detection in tropical heat. Dense, closed canopy is a hard limit, because heat cannot radiate up through it. Detection is also strongly time-dependent: one study measured feral pig detection at 50 to 75 percent in the early evening but only around 5 to 14 percent in the mid-afternoon. This is exactly why surveys are flown at dawn, dusk, or night, and favour the cooler months, when contrast is strongest and pigs and deer are most active.
The rules: CASA
Commercial drone work is regulated by the Civil Aviation Safety Authority. A drone under 2 kilograms can be flown for business without a remote pilot licence, but only under standard conditions: in daylight, within visual line of sight, below 400 feet, and clear of people and aerodromes. Because thermal surveys are usually flown at dawn or at night, they fall outside those standard conditions and require an operator’s certificate, a licensed remote pilot, and a documented risk assessment. A professional survey operator holds the right credentials and manages the approvals, so all you provide is property access.
Trail Cameras: The Continuous Watch
If the drone is the snapshot, the trail camera is the long watch. A weatherproof, motion-triggered camera sits at a chosen spot and records everything that passes, day and night, for weeks at a time. That patience is its power. It is how you learn the exact time and route pigs use to cross a creek into a crop, confirm whether a bait is being taken and by which species, keep an eye on a trap, and compare activity before and after control. NSW DPI runs more than 1,000 camera traps across the state for exactly these reasons.
What AI adds
The old problem with cameras was volume: 70 to 80 percent of the images are empty false triggers from wind and shadows, and sorting them by hand is slow. Artificial intelligence has solved that. Detection models like MegaDetector find the images that actually contain an animal at around 95 percent accuracy, and classifiers like Google’s SpeciesNet identify close to 2,500 species at 94.5 percent accuracy. One study found that pairing AI with 4G cameras cut processing effort by up to 81 percent. Instead of a card full of photos, you get a clean report of which species were present, how often, when, and where. For the full detail, see our guide on how trail cameras and AI are changing pest control.
Limits
A camera only sees where you put it. It watches one point, so covering a property means choosing your spots well, at creek crossings, gates, fence gaps, and known pads, rather than blanketing every paddock. Cameras also need power and, for real-time alerts, mobile coverage, with Telstra offering the widest rural 4G footprint. Lithium batteries help, lasting up to 12 months. None of this is a drawback so much as the trade-off for continuous, patient monitoring.
Use Both: The Survey and the Watch
The reason to see these as partners rather than rivals is that each covers the other’s blind spot. The drone sees the whole property but only for a moment; the camera sees only one spot but for weeks. Put them together and you get a monitoring programme that both counts and watches:
- Survey with the drone. Fly the property to find the hotspots, count the animals, and set a baseline.
- Place cameras on the corridors. Position trail cameras along the movement routes and at the bait and trap sites the survey reveals, so you have continuous eyes where the animals actually are.
- Run the control. Use the intelligence to place shooters, baits, and traps where they will work.
- Survey again. Fly the drone once more to measure the knockdown, and let the cameras confirm whether the survivors return.
This is how monitoring turns “we think there are fewer pigs” into “detections dropped by 80 percent”. See our thermal drone surveys and property assessment pages for how each fits a programme.
How We Help
We use both tools because most properties need both. We fly a thermal drone survey to count your feral animals and map where they are, deploy trail cameras with AI-assisted analysis to watch the corridors and bait sites, and pull the two together into a clear picture that guides ground shooting, baiting, and trapping. Then we survey again so you can see, in numbers, whether the programme worked. See our technology pages, or get in touch for a monitoring and control plan built around your property.
Sources consulted: Cox et al. (2023), Scientific Reports, thermal aerial culling (NSW DPI Vertebrate Pest Research Unit, University of New England, Flinders University); Wagner et al. (2025), Ecological Applications (University of Melbourne); Hvala et al. (2023), Frontiers in Conservation Science (Charles Darwin University); Gentle et al. (2026), Queensland DPI; Civil Aviation Safety Authority drone rules (flying at night, weight categories); National Feral Pig Action Plan (Western Riverina) and NSW Local Land Services infrared surveys; NSW DPI camera trapping, and the AI research cited in our trail camera guide.