Trade-offs and upper limits to signal performance during close-range vocal competition in gray treefrogs, Hyla versicolor

Performance limitations on signal production constrain signal evolution. Variation in signaling performance may be related to signaler quality and therefore is likely to be a salient aspect of communication systems. When multiple signal components are involved in communication, there may be trade-offs between components, and performance can be measured as the degree to which signalers approach the upper limits of the trade-off function. We examined vocal performance in the gray treefrog, Hyla versicolor, in which females prefer values of call duration and rate exceeding the usual range of variation within and among males. We recorded interactions between pairs of males calling on mobile platforms that allowed us to manipulate inter-male distance and place males in highly competitive environments. We found that although there was a clear upper boundary on the ability of males to maximize simultaneously call duration and call rate, call effort did not remain constant in this highly compet...

信号产生的性能限制制约着信号演化。信号性能的变异可能与信号发送者的质量相关，因此很可能是通信系统的一个显著方面。当通信涉及多个信号成分时，成分之间可能存在权衡（trade-off），而性能可通过信号发送者接近权衡函数上限的程度来衡量。我们研究了灰树蛙（Hyla versicolor）的发声性能——该物种的雌性偏好鸣叫持续时间和速率值超出雄性个体内及个体间的常规变异范围。我们记录了在移动平台上鸣叫的雄性配对间的互动，这些平台使我们能够操纵雄性间距离，并将其置于高度竞争的环境中。我们发现，尽管雄性同时最大化鸣叫持续时间与速率的能力存在明确上限，但在此高度竞争的...