Proceedings of the Vertebrate Pest Conference

Fumigation is the most effective method of rabbit (Oryctolagus cuniculus) control available in the United Kingdom. Use of current methods, involving formulations that generate hydrogen cyanide (HCN) or phosphine (PH3) on exposure to moisture, is limited by weather conditions. A carbon monoxide producing cartridge has been developed which can be used independent of weather conditions. The cartridge is similar in size to the smaller carbon monoxide (CO) cartridge used in the United States, but produces up to 70% more CO. High concentrations of CO were measured at the entrances of an unoccupied artificial warren fumigated with CO-cartridges, but these declined quickly. There was relatively little movement of CO through the warren but in most parts concentrations of ≥1% were maintained for one hour or more. Wind speed and direction were shown to have significant effects on CO concentration and distribution.