The Sensitivity of Australian Animals to 1080 Poison IV. Native and Introduced Rodents

Abstract

Most rodent species that have been tested in Australia and elsewhere are highly sensitive to 1080 poison. A few native species. particularly members of the 'pseudo-mouse group' (Conilurini), part of whose range is in Western Australia, are much more tolerant. These species may have developed this tolerance from being exposed to indigenous plants that contain fluoroacetate. The most common signs of poisoning amongst rodents are depression, hypersensitivity to stimuli, respiratory distress and convulsions. Signs of poisoning first appeared amongst the species tested in this study 0.4-38.1 h after dosing. Deaths occurred 0.7-205.8 h after dosing. The susceptibility to 1080-poisoning of the 14 species of rodents tested in Australia depends on both sensitivity and body size, and is discussed in relation to typical baits and concentrations of 1080 used against vertebrate pests. Individuals of most species of rodents would appear to face a considerable risk if pest-poisoning campaigns are carried out within their range, but the crucial factor governing the actual effect on populations will be how many individuals find and eat the baits.