[Article] 具苦味且有警戒訊息的被捕食者強化捕食行為的避忌偏好

原文標題：Bitter taste enhances predatory biases against aggregations of prey with warning coloration

摘要 [原文網址]

Aposematic prey that possess chemical defenses advertise these to potential predators using conspicuous warning coloration. Aposematism is often associated with group living, which is hypothesized to enhance the protection of these species. Predators exhibit unlearned biases against foods with warning coloration, and the presentation of a novel sound or bitter-tasting toxin augments these biases. Whether these nonvisual signal components also cause naive predators to more strongly avoid aggregated prey, and whether biases against aggregations are restricted to situations where aggregated prey possess visual signals typically associated with aposematism, is unknown. We conducted an experiment in which naive domestic chicks (Gallus gallus domesticus) acted as predators and used artificially colored pastry prey. The experiment had a 2×2 design in which naive birds were offered a drop of either water or bitter-tasting chloroquine solution before being given the choice between solitary and aggregated prey that were either both red, a typical aposematic color, or both green (usually associated with crypsis and palatability). We found that birds were warier of red-aggregated prey and attacked significantly more solitary prey before aggregated prey compared with green. After sampling bitter-tasting chloroquine solution, the birds showed a bias in their attack decisions, attacking significantly fewer aggregated prey in total compared with those who had sampled water, but only when prey were red. Thus, exposure to a bitter-tasting toxin affected predatory preferences. We discuss our findings in relation to the mechanisms of bias, the benefits of group living, and the evolution of warning coloration and aggregation.

聚集性的被捕食者具有次級防禦的話，更容易讓捕食者記憶起來並且避免捕食者類捕食者（一句話說完本文）。

這篇大致上就是在說上面那件事，雖然1996年時已經有一篇文章說明聚集性的捕食者的警戒訊息會比較有效，這篇更深入一點，討論的是「有次級防禦的話，更有效喔！」。

雖然文章中有一段，摘要中有一句在說明除了警戒訊號，如果有其他非視覺性的訊號，像是聲音、氣味等，更能強化捕食者的印象，雖然這個看起來很重要，不過文章中對於這個部分倒是沒有任何測試，還是只測試了味覺與視覺的聯想。