EAGER: Acoustic Differentiation of Northern Red-legged Frog Populations

EAGER：北方红腿蛙种群的声学分化

• 批准号: 1449319
• 负责人: Randy Zelick
• 金额: $ 6.2万
• 依托单位: Portland State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1449319&HistoricalAwards=false
• 关键词: EAGER; Acoustic; Differentiation; Northern; Red

A major question in understanding the natural world is how each species is able to successfully identify a mate to assure persistence of the species and how changing environmental conditions might influence its reproductive success. In many species male advertisement calls are essential for attracting a female to mate with as well as being used for species recognition when more than one species co-occurs within an area. The researchers have identified a novel system to quantify how male advertisement and recognition calls are altered when the calls are performed underwater among populations of northern red-legged frogs in the Pacific North West. This research on sound transmission and mating will be complemented by an investigation of the genetic differentiation among populations of this frog species throughout its geographic range. The research will be shared via an outreach initiative at Portland State University's "Better Know a Lab" that brings together the surrounding community and research labs to jointly conduct data collection all the way through to the presentation of their findings. Furthermore, networking is planned with local teachers to help design interdisciplinary curricula highlighting the role of communication, ecology, and the science of sound to engage students in learning about mating strategies and the important role animal communication plays in species successful persistence in nature. The sensory drive hypothesis asserts that sensory conditions (environmental biophysics) and sensory systems drive divergence in mate signaling in a particular direction, one that optimizes signal propagation ultimately through resultant reproductive success. This research is unique in testing the sensory drive hypothesis with a terrestrial anuran that (1) calls underwater and (2) calls in shallow ponds that may dramatically alter "normal" acoustic attenuation. Attenuation of acoustic signal components is generally proportional to the square of sound frequency; higher frequencies attenuate much more quickly. However it has been shown that in shallow ponds, substrate and depth can dramatically increase the attenuation of lower frequencies. Because the energetically dominant frequencies upon which female choice is based fall in the lower range of the signal, a system where low frequencies may be dramatically attenuated is far more likely to create reproductive isolation among frog populations than the previous systems studied. The project will test the acoustic and genetic differentiation of allopatric northern red-legged frog populations compared across ponds with significantly differing acoustic profiles across a large geographical scale. How well male advertisement calls are matched to the frequency profile of the breeding site should determine reproductive success and create directional selection on spectral characteristics, and provide a first test for the sensory drive hypothesis through the utilization of underwater calling.

理解自然界的一个主要问题是，每个物种如何能够成功地识别配偶，以确保物种的持续存在，以及不断变化的环境条件可能如何影响其繁殖成功。在许多物种中，雄性广告呼叫对于吸引雌性交配以及当一个地区内同时出现多个物种时被用于物种识别是必不可少的。研究人员已经发现了一种新的系统，可以量化雄性广告和识别呼叫在太平洋西北部北部红腿青蛙种群中在水下进行时的变化。这项关于声音传播和交配的研究将通过对整个地理范围内这种蛙类种群之间的遗传分化的调查来补充。这项研究将通过波特兰州立大学“更好地了解实验室”的推广活动来分享，该活动将周边社区和研究实验室聚集在一起，共同进行数据收集，直到展示他们的研究结果。此外，还计划与当地教师建立联系，帮助设计跨学科课程，突出传播学、生态学和声学的作用，让学生学习交配策略和动物交流在物种在自然界中成功维持的重要作用。感觉驱动假说断言，感觉条件(环境生物物理学)和感觉系统在特定方向上驱动配偶信号的分歧，该方向最终通过所产生的繁殖成功来优化信号传播。这项研究在测试感觉驱动假说方面是独一无二的，这种陆地无尾两栖动物(1)在水下叫声，(2)在浅水池中叫声，这可能会极大地改变“正常”的声音衰减。声信号分量的衰减通常与声音频率的平方成正比；频率越高，衰减越快。然而，已有研究表明，在浅水池中，底物和深度可以显著增加低频的衰减。由于雌性选择所基于的能量主导频率落在信号的较低范围内，因此，与之前研究的系统相比，低频可能显著减弱的系统更有可能在青蛙种群中造成生殖隔离。该项目将测试异地北方红腿青蛙种群的声学和遗传分化，并将其与大地理范围内声学特征明显不同的池塘进行比较。雄性广告叫声与繁殖地频率分布的匹配程度应该决定繁殖的成功与否，并对光谱特征进行定向选择，并通过利用水下叫声为感觉驱动假说提供第一个检验。