Artificial illumination reduces bait-take by small rainforest mammals

Small mammals often moderate their foraging behaviour in response to cues indicating a high local predation risk. We assessed the ability of cues associated with a high predation risk to reduce the consumption of bait by non-target small mammal species in a tropical rainforest, without inhibiting bait-take by feral pigs (Sus scrofa). The illumination of feeding stations with a low power light source caused small mammals to reduce their foraging intensity on sunflower seeds mixed through sand by 25% (P < 0.001) and on unprocessed corn-based feral pig bait by 80% (P < 0.001). Illumination also reduced the intensity with which small mammals fed on commercially manufactured baits (odds ratio = 6.17, P = 0.009). Illumination did not cause pigs to reduce their intake of corn bait (P = 0.43). Neither pig nor dingo (Canis lupus dingo) vocalisations had any detectable effect on the foraging intensity of small mammals (P > 0.05 for all treatments). We conclude that site illumination was an effective method of selectively deterring small mammals from consuming feral pig baits in our study region, but had no effect on consumption of those baits by pigs.