Early evenings, or wet season mornings, are the best times to survey feral pigs in the NT using aerial drone systems and GPS, a new Charles Darwin University study shows, with one researcher saying the knowledge could enhance population assessment accuracy, and enable effective wildlife management and conservation.

CDU North Australian Centre for Autonomous Systems director Professor Hamish Campbell said the study combined aerial drone surveying with GPS tracking to account for variations between the data, evaluating the time and environmental factors influencing detection and population estimates.

“Aerial drone systems are now widely used to survey wildlife, but they have their limitations, and validation in the detectability of individuals is rarely assessed. Studies like this will get the best conservation outcomes,” he said.

“Monitoring is a critical part of the success of any management program and data from studies like this ensure that we are creating robust and cost-effective programs.”

The results of the study were included in a paper titled Supplementing aerial drone surveys with biotelemetry data validates wildlife detection probabilities, which was published in the Frontiers journal.

Prof Campbell said the researchers released wild-caught feral pigs into a large natural habitat enclosure in northern Australia, and used a fixed wing drone equipped with dual thermal infrared and visible imaging sensor cameras to conduct flights over the area during both wet and dry seasons, from sunrise to sunset.

And he said they found detection probability was at its lowest during mid-afternoon, while the early evening had the highest detection probability of 50 to 75 per cent.

CDU PhD candidate Aliesha Hvala said the study found that the probability that a pig was visible from aerial imagery was highly variable.

“We observed seasonal differences, with detection probabilities exceeding 50 per cent in the mornings of the wet season, in contrast to less than 30 per cent during the dry season,” Ms Hvala said.

“GPS location data also enabled us to assess how canopy cover, land cover, and ambient temperature altered animal detection probability.”

NACAS researcher Dr Rebecca Rogers said the findings could help enhance the accuracy of population assessments and contribute to more effective wildlife management and conservation.

“Resources are often limited for wildlife management, so being able to target monitoring efforts will lead to better conservation outcomes,” she said.