兩個地理分隔族群的大山雀 (Parus major)對有警戒訊號的獵物的反應不一致
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摘要
Variation in predator behavior toward aposematic prey was frequently studied at interspecific and individual levels, but interpopulation differences have been neglected. Geographic differences in prey fauna offer an opportunity to test their implications for predator behavior. It can be expected that 1) predator populations inhabiting environments with high diversity of aposematic prey are more neophobic than those living in areas where aposematic prey are scarce, and 2) different levels of neophobia jointly with avoidance learning affect selection on aposematic prey. We compared the behavior of wild-caught great tits (Parus major) from Bohemia and Central Finland toward aposematic firebugs (Pyrrhocoris apterus), nonaposematic firebugs, novel objects and novel palatable nonaposematic prey. Finnish and Bohemian birds did not differ in their novel-object exploration, but Finnish birds hesitated longer than Bohemian birds before resuming feeding next to a novel object. Latencies to attack novel palatable prey did not differ and were not correlated with the attitude toward novel objects. Tits from the Bohemian population mostly avoided aposematic firebugs and attacked nonaposematic ones. Finnish birds were more likely to attack both firebug color forms, and their attack latencies were correlated with latencies of attacking novel palatable prey. Thus, Bohemian birds avoided the aposematic prey, but were not more neophobic than Finnish birds. These results suggest that differences between Finnish and Bohemian birds in behavior to aposematic prey do not follow differences in exploration strategy and neophobia. The observed differences can be explained by a different experience with local aposematic prey communities.
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photo from wiki
很多時候在討論捕食者對獵物如何如何判斷要不要攻擊的時候，這些文章的結果都會毫無理由的假設「因為所採用的物種是同種，所以牠們的反應都是在差異內」，這篇就在討論捕食者的反應到底會不會有差異，差多少，怎樣會有差異。
作者抓了芬蘭與波希米亞的大山雀來討論這樣的問題，讓牠們去吃firebug (Pyrrhocoris apterus，如上圖) 這種椿象。顯示在經過第一次嘗試新的獵物後，芬蘭的族群在下一次攻擊前的猶豫時間較長（要看很久才決定），但是吃一般獵物的時候這種就沒有這種差異。實驗中，波希米亞的族群顯然地會避免攻擊椿象而去攻擊非警戒色的獵物，芬蘭的族群則傾向兩者都攻擊，但在第二次攻擊的時候會比較延遲（要想一下）。
這樣的研究告訴我們，即使是同樣的物種，不同的族群也會使用不同的策略挑選獵物，因此在做這樣的實驗時，就必須要把這類的因素考慮進去，而不同對待獵物的策略就可能造成解釋獵物的擬態/警戒色的演化歷程的差異。
另外讓我想到的是，這個研究雖然討論到，但這樣策略的差異是先天的遺傳（天生下來就是這樣的個性）還是來自後天學習（媽媽這樣教我就這樣做，或是區域性的"文化"，朋友都這樣我也這樣），而行為的可塑性是否會影響不同區域擬態群的演化呢？
我很好奇（眼亮）
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