Proceedings of the Vertebrate Pest Conference

In Japan, the jungle crow (Corvus macrorhynchos) is a common problematic bird, causing significant economic damage. Previous attempts to mitigate conflict between crows and humans have generally been unsuccessful. Furthermore, it is not clear whether successful mitigation outcomes can be attributed to the effectiveness of control techniques. To directly examine the sensitivity of wild-caught jungle crows to a control technique, we observed their foraging behavior when auditory stimuli were applied to a single feeding patch (no-choice trial) or to one feeding patch but not the other (two-choice trial) in an outdoor cage. The auditory stimulus consisted of a low tone in the crow’s audible range (1 to 10 kHz), based on pink noise. In the no-choice trial, one feeding site was set up in a U-shaped experimental cage, and experiments were conducted under two conditions: 1) experimental sound presented at an 80 dB sound pressure level and 2) silence (i.e., control). In the two-choice trial, feeding sites were set up at both ends of the cage, and the auditory stimulus was presented at a sound pressure of 80 dB at only one of the feeding sites. All experiments were conducted with one individual at a time. The results of the no-choice trial showed that in the sound condition, as well as in the silent condition, all individuals started foraging in the presence of the sound, and there was no clear difference in foraging behavior between the two conditions presented. However, in the two-choice trial, the amount of food foraged in the feeding area under the silent condition was significantly higher than that in the feeding area under low-tone stimulus conditions. Our results suggest that jungle crows have relatively high noise tolerance; however, auditory stimulus is effective when an alternative foraging site is available. Further development of more complex experiments in captivity will elucidate the effectiveness of bird control techniques