Department of Environmental and Aquatic Sciences, Curtin University of Technology, Perth, Australia.
PLoS One. 2011 Jan 18;6(1):e14549. doi: 10.1371/journal.pone.0014549.
Animals typically show less habituation to biologically meaningful sounds than to novel signals. We might therefore expect that acoustic deterrents should be based on natural sounds.
We investigated responses by western grey kangaroos (Macropus fulignosus) towards playback of natural sounds (alarm foot stomps and Australian raven (Corvus coronoides) calls) and artificial sounds (faux snake hiss and bull whip crack). We then increased rate of presentation to examine whether animals would habituate. Finally, we varied frequency of playback to investigate optimal rates of delivery.
Nine behaviors clustered into five Principal Components. PC factors 1 and 2 (animals alert or looking, or hopping and moving out of area) accounted for 36% of variance. PC factor 3 (eating cessation, taking flight, movement out of area) accounted for 13% of variance. Factors 4 and 5 (relaxing, grooming and walking; 12 and 11% of variation, respectively) discontinued upon playback. The whip crack was most evocative; eating was reduced from 75% of time spent prior to playback to 6% following playback (post alarm stomp: 32%, raven call: 49%, hiss: 75%). Additionally, 24% of individuals took flight and moved out of area (50 m radius) in response to the whip crack (foot stomp: 0%, raven call: 8% and 4%, hiss: 6%). Increasing rate of presentation (12x/min ×2 min) caused 71% of animals to move out of the area.
CONCLUSIONS/SIGNIFICANCE: The bull whip crack, an artificial sound, was as effective as the alarm stomp at eliciting aversive behaviors. Kangaroos did not fully habituate despite hearing the signal up to 20x/min. Highest rates of playback did not elicit the greatest responses, suggesting that 'more is not always better'. Ultimately, by utilizing both artificial and biological sounds, predictability may be masked or offset, so that habituation is delayed and more effective deterrents may be produced.
与新奇信号相比，动物对具有生物学意义的声音的习惯化程度通常较低。因此，我们可能期望声音驱避剂应基于自然声音。
我们研究了西部灰袋鼠（Macropus fulignosus）对自然声音（警报脚步声和澳大利亚乌鸦（Corvus coronoides）叫声）和人工声音（假蛇嘶嘶声和牛鞭噼啪声）的反应。然后，我们增加了播放速度，以检查动物是否会习惯。最后，我们改变了播放频率，以调查最佳的传递频率。
九种行为聚类为五个主要成分。PC 因素 1 和 2（动物警觉或观察，或跳跃并移出区域）占 36%的方差。PC 因素 3（停止进食、起飞、移出区域）占 13%的方差。因素 4 和 5（放松、梳理和行走；分别占 12%和 11%的变化）在播放后停止。鞭子噼啪声最具感染力；与播放前相比，进食减少了 75%，降至 6%（警报声后：32%，乌鸦叫声：49%，嘶嘶声：75%）。此外，24%的个体在听到鞭子噼啪声时起飞并移出区域（50 米半径）（脚步声：0%，乌鸦叫声：8%和 4%，嘶嘶声：6%）。增加播放速度（12x/min ×2 min）导致 71%的动物移出该区域。
结论/意义：人工声音牛鞭噼啪声与警报声一样有效，可以引起讨厌的行为。尽管袋鼠听到信号的次数高达 20 次/分钟，但它们并没有完全习惯。最高的播放速度并没有引起最大的反应，这表明“更多并不总是更好”。最终，通过同时利用人工和生物声音，可预测性可能会被掩盖或抵消，从而延迟习惯化并产生更有效的驱避剂。
