Moss Cynthia F, Bohn Kari, Gilkenson Hannah, Surlykke Annemarie
Department of Psychology, Institute for Systems Research, University of Maryland, College Park, Maryland, United States of America.
PLoS Biol. 2006 Apr;4(4):e79. doi: 10.1371/journal.pbio.0040079. Epub 2006 Mar 7.
To successfully negotiate a complex environment, an animal must control the timing of motor behaviors in coordination with dynamic sensory information. Here, we report on adaptive temporal control of vocal-motor behavior in an echolocating bat, Eptesicus fuscus, as it captured tethered insects close to background vegetation. Recordings of the bat's sonar vocalizations were synchronized with high-speed video images that were used to reconstruct the bat's three-dimensional flight path and the positions of target and vegetation. When the bat encountered the difficult task of taking insects as close as 10-20 cm from the vegetation, its behavior changed significantly from that under open room conditions. Its success rate decreased by about 50%, its time to initiate interception increased by a factor of ten, and its high repetition rate "terminal buzz" decreased in duration by a factor of three. Under all conditions, the bat produced prominent sonar "strobe groups," clusters of echolocation pulses with stable intervals. In the final stages of insect capture, the bat produced strobe groups at a higher incidence when the insect was positioned near clutter. Strobe groups occurred at all phases of the wingbeat (and inferred respiration) cycle, challenging the hypothesis of strict synchronization between respiration and sound production in echolocating bats. The results of this study provide a clear demonstration of temporal vocal-motor control that directly impacts the signals used for perception.
为了在复杂环境中成功导航，动物必须根据动态感官信息来控制运动行为的时间。在此，我们报告了棕蝠（Eptesicus fuscus）在捕捉靠近背景植被的系留昆虫时，其发声运动行为的适应性时间控制情况。对蝙蝠的声纳发声记录与高速视频图像同步，这些图像用于重建蝙蝠的三维飞行路径以及目标和植被的位置。当蝙蝠遇到在距离植被仅10 - 20厘米处捕捉昆虫的艰巨任务时，其行为与在开阔房间条件下相比发生了显著变化。其成功率下降了约50%，发起拦截的时间增加了十倍，并且其高重复率的“终端 buzz”持续时间缩短了三分之一。在所有条件下，蝙蝠都会产生显著的声纳“频闪组”，即具有稳定间隔的回声定位脉冲簇。在昆虫捕捉的最后阶段，当昆虫位于靠近杂物处时，蝙蝠产生频闪组的发生率更高。频闪组出现在翼拍（以及推断的呼吸）周期的所有阶段，这对回声定位蝙蝠呼吸与发声严格同步的假设提出了挑战。这项研究的结果清楚地证明了时间发声运动控制，这种控制直接影响用于感知的信号。
