Estimated 1080 dose rate for the M-44 ejector for the control of red foxes (Vulpes vulpes)

Abstract

Recent studies have suggested that bait movement and caching by foxes (Vulpes vulpes) may increase the potential risk of off-target effects from 1080 meat baits close to urban habitats. The M-44 ejector is an alternative way to deliver 1080 to foxes that will eliminate bait movement and caching. Whilst the M-44 ejector has been used for the control of foxes using cyanide in the United States, we investigated its use with 1080 as a toxicant. Exotic eutherian carnivores are generally more sensitive to 1080 than are most Australian endemic wildlife species, yet no useful difference in sensitivity to cyanide exists for these groups. The lower risk associated with occupational exposure to 1080 compared with cyanide suggests that it is a more desirable toxicant for fox control. Pen trials were undertaken in order to establish an appropriate capsule dose of 1080 to be used in the ejector. A minimum capsule dose of 2.7 mg of 1080 is estimated to be consistently lethal to foxes weighing up to 8.3 kg. The recommended dose is below the current meat bait dose of 3.0 mg 1080 used in Victoria. This may represent an improvement in occupational safety and a reduction in non-target risk.