The development of a carbon monoxide producing cartridge for rabbit control

Abstract

A new method of rabbit control has been developed using carbon monoxide generated by ignition of a cartridge containing sodium nitrate, charcoal and zinc oxide. Ignition of cartridges inside the entrances of an unoccupied artificial rabbit warren showed that carbon monoxide dispersed poorly through the warren and diffused out of the warren within 3–4 hours. Wind speed and direction markedly affected the distribution and persistence of carbon monoxide. Nevertheless, concentrations of carbon monoxide within most of the warren were sufficiently high to render rabbits rapidly insensible, but in some deeper parts of the warren, they remained at low levels, unlikely to have any effect on rabbits. Field trials showed that treatment of rabbit warrens with carbon monoxide cartridges (79 ± 10.8% kill) was as effective as treatment with cyanide powder (78 ± 11.9% kill), and suggested that rabbits were quickly rendered insensible. Therefore the technique shows considerable promise as an effective, safe and relatively humane method of rabbit control.