Use conditioned taste aversion to prevent non-target species from entering traps
Overall effectiveness category Likely to be beneficial
Number of studies: 1
Background information and definitions
Animals may be trapped for a variety of reasons. In cases, such as where trapping is aimed at non-native species, a large number of traps might be set across the landscape. If there is a risk of catching non-target species, these will typically be live traps, from which individuals of non-target species can be released. However, trapping of animals usually entails at least some risk of injury to the animal as well as further risks, such as keeping parents away from their young. Furthermore, a trap holding a non-target animal is generally not then available for capturing the target animal until next visited by an operator. Conditioned taste aversion may be attempted, to try to make non-target mammals that are at risk of capture avoid traps because they associate them with an unpleasant taste or sensation.
Supporting evidence from individual studies
A replicated, controlled study in 1992–1993 on an island in California, USA (Phillips & Winchell 2011) found that lacing bait with lithium chloride reduced the rate of entry of San Clemente Island foxes Urocyon littoralis clementae into traps for feral cats Felis catus. In the first year, fewer foxes were recaptured using lithium chloride bait in traps (at 200 mg dose/kg of fox - 9% recaught) than using unlaced bait (52% recaught). In the second year, fewer foxes were recaptured in traps using lithium chloride bait (3% recaught) than using unlaced bait (30% recaught). In sites where lithium chloride bait was used for 41 days and then switched to non-laced baits, recapture rates remained low for around 10 days after the switch, and then increased. Baits were placed in cage traps on a 146-km2 island. In 1992, two areas received lithium chloride baits (which induce gastrointestinal discomfort) and unlaced baits were used in three areas. In 1993, two areas received lithium chloride baits which were then switched to unlaced baits after 41 days and seven areas received unlaced baits throughout. Eight to 20 traps were used/area. Baits comprised 50 g of mixed cat food, tuna and raw hamburger, placed in traps from February through to July–August in 1992–1993.Study and other actions tested