Many animals rely on the integration of senses to interact with their environment. While most studies on multisensory integration focus on animals that use passive sensing, fewer studies have investigated actively sensing animals, such as animals that use echolocation. Prior work has demonstrated that bats and dolphins have the ability to perceive objects through both echolocation and vision and may integrate information across senses to improve target identification. Less is known, however, about how these animals might modify their active sensing systems when additional sensory input, such as visual cues, is available. In this study, we examine how Brazilian free-tailed bats, Tadarida brasiliensis, in the wild use their echolocation calls during night compared to day under two different sensory challenges: ground detection in an open field and roost localization in a complex and cluttered environment at a cave edge. Both location and light condition had a significant effect on call frequency and call duration. Echolocation calls had shorter durations and wider bandwidths during night compared to day, and this effect was more pronounced during roost localization at the complex cave edge. These results suggest that bats may use vision to supplement echolocation, but modifications to their sensing systems may depend on environmental complexity and/or sensorimotor challenges.

中文翻译：

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昼夜不同：当存在视觉线索时，野蝙蝠在复杂环境中修改回声定位

许多动物依靠感官的整合与环境互动。虽然大多数关于多感官整合的研究都集中在使用被动感知的动物上，但很少有研究调查主动感知动物，例如使用回声定位的动物。先前的工作表明，蝙蝠和海豚具有通过回声定位和视觉感知物体的能力，并且可以整合跨感官的信息以提高目标识别能力。然而，当有额外的感官输入（如视觉线索）可用时，这些动物如何修改它们的主动感知系统却知之甚少。在这项研究中，我们研究了巴西无尾蝙蝠 Tadarida brasiliensis 在野外如何在夜间与白天在两种不同的感官挑战下使用它们的回声定位呼叫：开阔场地中的地面检测和洞穴边缘复杂杂乱环境中的栖息地定位。位置和光线条件对通话频率和通话持续时间都有显着影响。与白天相比，夜间回声定位呼叫的持续时间更短，带宽更宽，这种效应在复杂洞穴边缘的栖息地定位期间更为明显。这些结果表明蝙蝠可能使用视觉来补充回声定位，但对其传感系统的修改可能取决于环境复杂性和/或感觉运动挑战。这种效应在复杂洞穴边缘的栖息地定位过程中更为明显。这些结果表明蝙蝠可能使用视觉来补充回声定位，但对其传感系统的修改可能取决于环境复杂性和/或感觉运动挑战。这种效应在复杂洞穴边缘的栖息地定位过程中更为明显。这些结果表明蝙蝠可能使用视觉来补充回声定位，但对其传感系统的修改可能取决于环境复杂性和/或感觉运动挑战。