Warning Signal Brightness Variation: Sexual Selection May Work under the Radar of Natural Selection in Populations of a Polytypic Poison Frog
Warning Signal Brightness Variation: Sexual Selection May Work under the Radar of Natural Selection in Populations of a Polytypic Poison Frog
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DOI：
10.1086/670010
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发表时间：
2013-05-01
影响因子：
2.9
通讯作者：
Cummings, Molly E.
中科院分区：
文献类型：
--
作者：
Crothers, Laura R.;Cummings, Molly E.
虽然理论上预测了在非同源物种中警告信号的一致性，以促进捕食者的学习，但这些信号的变化经常发生在自然界中。草莓毒蛙Dendrobates Pumilio是一种异常多型(种群表型不同)的失语型青蛙，在警告颜色和亮度上表现出变化。在Solarte种群中，雄性和雌性对雄性亮度变化的反应都不同。在这里，我们通过分光光度和可视模型证明，该种群内的位置亮度变化可能对两种假定的捕食者(螃蟹、蛇)和同种动物可见，但对假定的主要捕食者(鸟类)不可见。因此，这项研究表明，纤毛虫种群内的信号亮度可以通过性选择来塑造，但由于捕食者感官的限制，自然选择影响这一特征的机会有限。由于信号亮度的变化最终会导致色调的变化，我们在种群内水平上的发现可以为在跨种群尺度上理解这种多型性提供见解。
Though theory predicts consistency of warning signals in aposematic species to facilitate predator learning, variation in these signals often occurs in nature. The strawberry poison frog Dendrobates pumilio is an exceptionally polytypic (populations are phenotypically distinct) aposematic frog exhibiting variation in warning color and brightness. In the Solarte population, males and females both respond differentially to male brightness variation. Here, we demonstrate through spectrophotometry and visual modeling that aposematic brightness variation within this population is likely visible to two putative predators (crabs, snakes) and conspecifics but not to the presumed major predator (birds). This study thus suggests that signal brightness within D. pumilio populations can be shaped by sexual selection, with limited opportunity for natural selection to influence this trait due to predator sensory constraints. Because signal brightness changes can ultimately lead to changes in hue, our findings at the within-population level can provide insights into understanding this polytypism at across-population scales.