有毒的虎蛾歷史上是有警告色的昆蟲(chóng)的著名例子；后來(lái)人們發(fā)現(xiàn),，蝙蝠將這些昆蟲(chóng)所產(chǎn)生的超聲波與毒性聯(lián)系在一起，而且無(wú)毒物種也能得益于發(fā)出類似的聲音,。
在對(duì)加拿大東南安大略26種蛾子所做的一項(xiàng)研究中,，John Ratcliffe 和Marie Nydam發(fā)現(xiàn)，虎蛾的警告信號(hào)隨著一年中時(shí)間的不同而變化,，因此也隨著它們最有可能碰到的捕食者的類型而變化,。在春天出現(xiàn)的蛾子物種，往往用視覺(jué)信號(hào)如鮮艷的色彩來(lái)警告捕食者,，告訴它們自己是不能吃的,，因?yàn)樵诖禾禅B(niǎo)類是其最大的威脅。在夏天出現(xiàn)的蛾子物種更多地依靠超聲來(lái)趕走能夠進(jìn)行回聲定位的蝙蝠,，后者在夏季對(duì)其構(gòu)成主要威脅,。同樣，在白天活躍的物種更多地依靠視覺(jué)警告信號(hào),，而超聲信號(hào)在晚上更有用,。
這項(xiàng)研究說(shuō)明了，來(lái)自兩種截然不同捕食者的選擇壓力何以能夠引導(dǎo)昆蟲(chóng)警告系統(tǒng)中不同組成部分的演化,，從而導(dǎo)致同一物種內(nèi)擁有多樣化的對(duì)抗捕食者的防衛(wèi)體系,。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 455, 96-99 (4 September 2008) | doi:10.1038/nature07087
Multimodal warning signals for a multiple predator world
John M. Ratcliffe1,3 & Marie L. Nydam2,3
1 Center for Sound Communication, Institute of Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
2 Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York 14853, USA
3 These authors contributed equally to this work.
Aposematism is an anti-predator defence, dependent on a predator's ability to associate unprofitable prey with a prey-borne signal1. Multimodal signals should vary in efficacy according to the sensory systems of different predators; however, until now, the impact of multiple predator classes on the evolution of these signals had not been investigated2, 3. Here, using a community-level molecular phylogeny to generate phylogenetically independent contrasts, we show that warning signals of tiger moths vary according to the seasonal and daily activity patterns of birds and bats—predators with divergent sensory capacities. Many tiger moths advertise chemical defence4, 5 using conspicuous colouration and/or ultrasonic clicks3, 6. During spring, when birds are active and bats less so, we found that tiger moths did not produce ultrasonic clicks. Throughout both spring and summer, tiger moths most active during the day were visually conspicuous. Those species emerging later in the season produced ultrasonic clicks; those that were most nocturnal were visually cryptic. Our results indicate that selective pressures from multiple predator classes have distinct roles in the evolution of multimodal warning displays now effective against a single predator class. We also suggest that the evolution of acoustic warning signals may lack the theoretical difficulties associated with the origination of conspicuous colouration.
