Motus automated telemetry uncovers migratory shorebirds habitat selection, supporting adaptive land management

Estuaries provide vital social, cultural, economic, and environmental services to human societies worldwide, including 19 million coastal Australians, but rank among the most heavily used and threatened ecosystems. Australian coastal estuaries support around 50 shorebird species, many of which have declined sharply in recent decades due to habitat loss, disturbance, and introduced predators. Conserving these species depends on protecting and restoring habitats throughout their range, including estuaries, yet knowledge gaps persist regarding shorebird spatial ecology at night and during low tides—periods critical for foraging but involving heightened vulnerability to predation.​ High-tide roosting sites are well documented through daytime surveys, but habitats used at night and low tides, when shorebirds disperse to forage, remain poorly understood. These gaps limit effective adaptive land management and evidence-based conservation. Our study addressed this by deploying an array of eight Motus automated telemetry stations to quantify fine-scale habitat use within the Hunter Estuary, including a Ramsar-listed wetland of international importance. The array combines omnidirectional and directional antennas, which listen 24/7 for pulses of individually encoded, high temporal resolution (~15s pulse interval) Lotek nanotags attached to shorebirds. Tidal and circadian cycles were superimposed on detection periods, with variations in signal strength examined to distinguish resting from activity.​ This comparative dataset reveals for the first time species-specific patterns of estuarine use at night and during low tide, providing new knowledge of habitat preferences and movement ecology. It establishes a foundation for research into habitat selection drivers, such as food resources and predation risks by invasive predators. The study illustrates how patterns of movement revealed by automated telemetry can be combined with other ecological data (GPS, eDNA, camera trapping, stable isotopes) to unravel drivers of shorebird movements and determine whether some habitats not used by shorebirds nevertheless contribute to their conservation. Hence, comprehensive estuary-level shorebird movement data from a Motus array supports evidence-based land management decisions and adaptive management at the spatial scale where conservation action is typically implemented.