The Trajectory and Structural Integrity of Aerially Deployed Manufactured Baits for Canid Control

ABSTRACT In Australia, poison baits are aerially deployed in remote and inaccessible areas to mitigate invasive animal impacts. Program efficacy and compliance with mandated distance restrictions require accurate bait distribution but deployment accuracy and precision have not been evaluated for Doggone manufactured baits. We aimed to measure bait drift from the release point; assess bait availability to the target species; and evaluate bait matrix integrity upon impact. Under standard aerial baiting conditions, a helicopter deployed 100 Doggone baits fitted with VHF transmitters along transects on open ( n = 50) or forested agricultural land ( n = 50), and 50 baits without transmitters (controls) were deployed in open land. GPS waypoints were recorded as each bait was released from the helicopter, as were their landing positions. Bait availability and structural integrity were also assessed. Baits with transmitters travelled substantially farther (89.83 ± 15.26 m) than controls (61.61 ± 16.83 m) but with lower horizontal displacement from the flight line (3.68 ± 3.21 m cf. 4.95 ± 3.34 m, respectively) and with 84% landing to the right. Most baits (97%) remained accessible to wild dogs. The Doggone matrix was highly stable, with only one bait fracturing and four disintegrating during impact trials. Doggone baits are suitable for helicopter deployment in eastern NSW and the accuracy of deployment is appropriate for conformity with mandated distance restrictions. Aerial baiting transects should be curtailed 100 m from restricted zones to ensure aerial baiting buffer requirements are met. Deployment accuracy will be dependent on the aircraft and chute orientation. However, for studies similar to ours, accuracy could be improved by flying 5 m left of designated transects.