圖片取自本文
標題：The functional significance of aposematic signals: geographic variation in the responses of widespread lizard predators to colourful invertebrate prey
Conspicuous colouration can evolve as a primary defence mechanism that advertises unprofitability and discourages predatory attacks. Geographic overlap is a primary determinant of whether individual predators encounter, and thus learn to avoid, such aposematic prey. We experimentally tested whether the conspicuous colouration displayed by Old World pachyrhynchid weevils (Pachyrhynchus tobafolius and Kashotonus multipunctatus) deters predation by visual predators (Swinhoe’s tree lizard; Agamidae, Japalura swinhonis). During staged encounters, sympatric lizards attacked weevils without conspicuous patterns at higher rates than weevils with intact conspicuous patterns, whereas allopatric lizards attacked weevils with intact patterns at higher rates than sympatric lizards. Sympatric lizards also attacked masked weevils at lower rates, suggesting that other attributes of the weevils (size/shape/smell) also facilitate recognition. Allopatric lizards rapidly learned to avoid weevils after only a single encounter, and maintained aversive behaviours for more than three weeks. The imperfect ability of visual predators to recognize potential prey as unpalatable, both in the presence and absence of the aposematic signal, may help explain how diverse forms of mimicry exploit the predator’s visual system to deter predation.
如果就一個警戒性的物種來說，紅、黃、黑是基本的配色，因此球背象鼻蟲在一般的狀況下不會被認為是有警戒性的物種，進一步來說的話，黑綠配色更有可能被認為是隱蔽色。
可是球背象鼻蟲之所以會被認為可能具有警戒性，就是因為有個擬硬象天牛擬態斷紋球背象鼻蟲（下圖），如果這真的是有警戒性的話，那麼防禦機制來自哪裡呢？常常聽到有人說球背象鼻蟲很硬，這種物理性的硬度可以用來當成防禦嗎？另一個對於球背象鼻蟲的研究困難在於全屬都是保育類，申請的繁複以及考慮野外族群的數量都增加困難度。
球背象鼻蟲屬 (Pachyrrhynchus spp.) 與擬硬象天牛屬( Doliops spp.)間的擬態關係
本篇文章是由師範大學的林仲平教授與科博館黃文山主任的團隊進行的研究主題。作者們使用分佈在蘭嶼的小圓斑球背象鼻蟲 （Pachyrhynchus tobafolius ）與綠島的碎斑硬象鼻蟲 （Kashotonus multipunctatus）為研究材料，將其斑紋維持原樣或是塗黑處理（見最上面圖），捕食者則選用與象鼻蟲共域或不共域的斯文豪氏攀蜥（Japalura swinhonis）族群，以此進行取食試驗。結果顯示共域的攀蜥會攻擊塗黑的而避免攻擊有斑點的個體，而不共域的攀蜥對有斑點的個體的攻擊率高於共域的攀蜥。共域的蜥蜴對於塗黑的個體攻擊率也不高，顯示可能有其他的因子協同影響蜥蜴的學習。不共域的蜥蜴很快的學到這些個體的不可食性，也就顯示蜥蜴很快的將視覺訊號與硬度連結，這個物理性的硬度的確可以做為防禦。
不知道換成鳥這種直接吞的捕食者會不會有差異？
ps. 昨天突然發現這篇安安靜靜的躺在我的草稿裡兩年，就讓我默默的放出來吧.....
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