A bait efficacy trial for the management of feral cats on Christmas Island

Arthur Rylah institute for Environmental Research, 2010

Threat abatement project
Michael Johnston, Dave Algar, Neil Hamilton and Michael Lindeman
Arthur Rylah Institute for Environmental Reserch, Victorian Department of Sustainability and Environment. Western Australian Department of Environment and Conservation in parternship with the Department of the Environment, Water, Heritage and the Arts

Summary

The development of an effective bait and toxin for managing feral cat (Felis catus) populations within Australia is regarded as a very high priority in the ‘Threat Abatement Plan for Predation by Feral Cats’ (DEWHA 2008). A collaborative project has addressed this by using an existing fresh meat bait (Eradicat®) that is known to be attractive to feral cats and developed a toxicant formulation based on para-aminopropiophenone (PAPP). This compound was selected on the basis of its apparent humane mode of action and the published differences in susceptibility between cats and non-target species. Further minimisation of the hazard to non-target species is addressed by presenting the PAPP in a very hard pellet that has been found to be reliably consumed by feral cats but rejected by many other species. The overriding objective of the project is to complete the necessary research to achieve registration of the Curiosity® bait as an agricultural chemical.

A field efficacy trial of the Curiosity® bait was undertaken on Christmas Island in the Indian Ocean during August–October 2009. The objective of this study was to assess whether the bait was an effective tool for the management of a feral cat population in a tropical climate. The activity of feral cats was quantified before and after the poison bait program by measuring the rate of bait removal and visits to ‘active’ sand pads.

Feral cat activity at the monitoring pads was observed to decrease by 87% in the post-bait monitoring period from pre-baiting levels, indicating that the bait provided an effective feral cat population management technique. The procedures used in this study did not permit determination of the actual number of feral cats that died during the trial. However, this number will be between the estimated minimum of 38 and maximum of 78 feral cats that removed baits containing the PAPP toxicant.

Because the management of feral cats on Christmas Island is complicated by the abundant native crab species that would rapidly consume baits placed on the ground, baits were suspended above the ground from a pre-fabricated device. This trial recorded a very low (1.3%) rate of bait removal by non-target species over a total of 7860 bait nights.

The trial indicated that the Curiosity® bait, when used in conjunction with the bait suspension device, can provide a highly target-specific technique for the management of a feral cat population in a tropical climate.