Glucocorticoid-Mediated Changes in Male Green Treefrog Vocalizations Alter Attractiveness to Females
Glucocorticoid-Mediated Changes in Male Green Treefrog Vocalizations Alter Attractiveness to Females
复制标题
糖皮质激素介导的雄性绿树蛙发声变化改变了对雌性的吸引力
DOI：
10.1093/icb/icab053
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发表时间：
2021
影响因子：
2.6
通讯作者：
Kennedy, Joseph G
中科院分区：
文献类型：
--
作者：
Leary, Christopher J;Crocker-Buta, Sarah;Holloway, Ashli;Kennedy, Joseph G
肾上腺糖皮质激素(GC)越来越被认为是男性求爱信号的重要调节器，这表明这些类固醇的循环水平在性选择中发挥着核心作用。然而，很少有研究研究GC对男性性信号的影响是否真的会影响女性的配偶选择。在这里，我们研究了皮质酮(CORT)介导的雄性绿色树蛙发声的变化如何影响对雌性的吸引力。在这一物种中，竞争对手之间争夺配偶的雄性之间的激励性声音信号增加了竞赛失败者的循环皮质醇水平。皮质醇的急剧升高反过来减少了男性广告呼叫的持续时间，增加了连续呼叫之间的潜伏期，导致发声努力(每单位时间的信号量)的净减少，这与循环中雄激素的变化无关。基于对声学特征的已知偏好。在灰熊和其他无尾两栖动物物种中，皮质醇对时间呼叫特征的影响的方向预计会损害对雌性的吸引力，但它们是否具有足够的影响雌性配偶选择决定的程度尚不清楚。为了检验皮质醇对男性广告通话的影响是否降低了对女性的吸引力，我们在双扬声器回放实验中播放了发声，其发声接近于平均通话时长和发声努力值(受皮质醇升高影响的两个主要发声特征)的平均值和1SD。结果显示，在使用近似平均值和高于平均通话时长和发声努力值1SD的测试中，雌性对低Cort雄性的叫声特征表现出强烈的偏好，但在使用低于平均值约1SD的呼叫值的试验中，雌性并不表现出对低Cort雄性的叫声的偏好。总体而言，雌性更喜欢具有预测低皮质醇的信号特征的雄性，然而，当信号选择仅略有差异时，这种效应是非线性的，偏好减弱，这表明可能存在阈值效应。具体地说，女性似乎主要根据与皮质醇介导的通话时长和发声努力的变化相关的呼叫率的差异来区分CORT低和高的男性。我们的结果强调，在男性和男性发声互动过程中，循环皮质醇的变化会降低对女性的吸引力，这表明循环中的皮质醇水平在两性选择中都可以发挥关键作用。
Adrenal glucocorticoids (GCs) are increasingly recognized as important modulators of male courtship signals, suggesting that circulating levels of these steroids can play a central role in sexual selection. However, few studies have examined whether GC-mediated effects on male sexual signals actually impact mate choice by females. Here, we examine how corticosterone (CORT)-mediated changes in the vocalizations of male green treefrogs,Dryophytes cinereus, influence attractiveness to females. In this species, agonistic acoustic signaling between rival males competing for mates increases circulating CORT levels in contest losers. Acute elevations in CORT, in turn, decrease the duration of male advertisement calls and increase the latency between successive calls, resulting in a net reduction in vocal effort (the amount of signaling per unit time) that occurs independently of changes in circulating androgens. Based on known preferences for acoustic features inD. cinereus, and other anuran species, the direction of CORT-mediated effects on temporal call characteristics is expected to compromise attractiveness to females, but whether they are of sufficient magnitude to impact female mate choice decisions is unclear. To examine whether CORT-mediated effects on male advertisement calls reduce attractiveness to females, we broadcast vocalizations in dual speaker playback experiments approximating the mean and 1 SD above and below the mean call duration and vocal effort values (the two primary vocal features impacted by elevated CORT) of males with low and high CORT levels. Results revealed strong preferences by females for the calls characteristic of males with low CORT in tests using the approximate mean and 1 SD above the mean call duration and vocal effort values, but females did not show a preference for calls of males with low CORT in trials using call values approximating 1 SD below the mean. Overall, females preferred males with signal traits predictive of low CORT, however this effect was nonlinear with attenuated preferences when signal alternatives differed only marginally indicating a possible thresholding effect. Specifically, females appeared to discriminate between males with low versus high CORT based primarily on differences in call rates associated with CORT-mediated changes in call duration and vocal effort. Our results highlight that changes in circulating CORT during male–male vocal interactions can decrease attractiveness to females, suggesting that circulating levels of CORT can play a critical role in both intra- and intersexual selection.