Fish avoid visually noisy environments where prey targeting is reduced

The environment contains different forms of ecological noise that can reduce the ability of animals to detect information. Here we ask whether animals adapt their behaviour to either exploit or avoid areas of their environment with increased dynamic visual noise. Three-spined sticklebacks (Gasterosteus aculeatus) were immersed into environments with a simulated form of naturally occurring visual noise – moving light bands that form on underwater substrates caused by the refraction of light through surface waves. We tested whether this form of visual noise affected fish's habitat selection, movements, and prey-targeting behaviour. Fish avoided areas of the environment with increased visual noise, and achieved this by increasing their activity as a function of the locally perceived noise level. Fish were less likely to respond to virtual prey in environments with increased visual noise, highlighting a potential impact that visual noise has on their perceptual abilities. Fish did not increase or decrease their refuge use in environments with increased visual noise, providing no evidence that visual noise either increased exploratory, or, risk aversive behaviour. Our results indicate that animals can use simple behavioural strategies to avoid visually noisy environments, thereby mitigating the impacts these environments appear to have on their perceptual abilities.

本实验环境包含多种形式的生态噪声（ecological noise），此类噪声会削弱动物的信息探测能力。本研究旨在探究动物是否会调整自身行为，以利用或规避环境中动态视觉噪声（dynamic visual noise）增强的区域。我们选取三刺棘鱼（Three-spined sticklebacks，Gasterosteus aculeatus）作为实验对象，将其置于模拟自然视觉噪声的环境中——该噪声由光线经水面波浪折射后在水下基底形成的移动光带所构成。我们测试了此种视觉噪声是否会影响鱼类的栖息地选择、运动行为以及猎物靶向行为。实验结果显示，鱼类会主动规避视觉噪声增强的环境区域，且它们通过提升自身活动量以匹配局部感知到的噪声水平来实现这一规避行为。在视觉噪声增强的环境中，鱼类对虚拟猎物的响应概率显著降低，这凸显出视觉噪声可能对其感知能力造成的潜在影响。当环境视觉噪声增强时，鱼类并未改变其避难所使用频率，由此未发现视觉噪声会提升鱼类探索行为或增强其风险规避倾向的证据。本研究结果表明，动物可通过简单的行为策略规避视觉噪声较强的环境，从而减轻此类环境对其感知能力造成的负面影响。