Aerially deployed baits in the northern rangelands of Western Australia are available to wild dogs

Abstract

Context Aerial baiting using fixed-wing aircraft is an effective method of bait delivery for wild-dog control in remote locations. However, aerial baiting may result in loss of baits to positions that are inaccessible to wild dogs. Attempts, by landholders, to address such bait loss through compensatory baiting may increase baiting costs and potential risks to non-target species. Aims To assess bait drift under standard baiting conditions. To assess the availability of aerially deployed baits to wild dogs across several commonly baited landforms in the northern rangelands of Western Australia. Methods We determined drift characteristics of baits deployed under standard fixed-wing baiting conditions. We then determined the availability of aerially deployed baits by deploying baits with embedded radio-transmitters across four commonly baited landforms (riparian vegetation, tussock grassland, gorges and breakaways). We then visually assessed the availability of relocated baits (as ‘high’, ‘moderate’ or ‘low’). Key results Under standard fixed-wing baiting conditions, on average, baits fell 100.9 m forward, and 8.3 m laterally, from the point-of-release. Across all landforms, most baits (91.8%) were highly available, with a further 7.0% falling into the moderate category and 1.2% in the low category. There were significant differences in bait availability among landforms, with the proportion of moderate-low availability baits greatest in gorges and lowest on tussock grassland. Conclusions Within the northern rangelands of Western Australia, bait wastage owing to deployment in inaccessible locations is minimal. Implications Compensatory baiting for lost baits is unnecessary and increases costs to land managers.