A new method of rabbit control has been developed using carbon monoxid
e generated by ignition of a cartridge containing sodium nitrate, char
coal and zinc oxide. Ignition of cartridges inside the entrances of an
unoccupied artificial rabbit warren showed that carbon monoxide dispe
rsed 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 ca
rbon monoxide within most of the warren were sufficiently high to rend
er 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 monox
ide cartridges (79 +/- 10.8% kill) was as effective as treatment with
cyanide powder (78 +/- 11.9% kill), and suggested that rabbits were qu
ickly rendered insensible. Therefore the technique shows considerable
promise as an effective, safe and relatively humane method of rabbit c
ontrol.