Field enclosure experiments on the technique of poisoning the rabbit, Oryctolagus cuniculus (L.). III. A study of territorial behaviour and furrow poisoning

Abstract

A 2-acre enclosure was stocked with wild rabbits, Oryctolagus cuniculus (L.), which were left to develop social groups and, later, territories associated with breeding. A furrow was then drawn within the enclosure and free-fed first with carrot and finally with carrot containing 0.04% sodium fluoroacetate ("1080"). The reaction of the rabbits to the furrow and bait was observed. Territorial restrictions permitted rabbits ready access only to parts of the furrow within or adjacent to their own territories. The furrow did not attract rabbits and was first treated with suspicion until accepted as part of their territory. The social commitments of individual rabbits, particularly if centred away from the furrow, affected their feeding behaviour. Thus males were distracted from feeding in the furrow by intruders from neighbouring territories, or gave chase to oestrous females, while young kittens and parturient or post-partum females remained close to their nests, frequently avoiding contact with the furrow. Following the death of their mothers, nestlings aged more than 17 days can survive, provided the environmental conditions are favourable. The average time spent feeding on poisoned carrot, prior to the onset of toxic symptoms, was 10 min, during which rabbits ate an average of 15.9 g of bait, sufficient to kill three adult rabbits. This indicates that the concentration of "1080" could be cut to 0.02 % without loss of efficiency; this would ensure greater protection for stock and fauna. Because kittens are absent during late summer, when the territorial consciousness of rabbits is minimal, this is the best time of the year for furrow-poisoning.