Behavioral plasticity is a key factor facilitating the coexistence of humans and other species in a rapidly urbanizing world. An animal’s anti-predation ability is usually estimated by measuring its flight initiation distance (FID). FIDs in birds are affected by multiple factors including the color of the observer’s clothing. The species confidence hypothesis argues that birds are attracted to colors which are the same as or similar to that of their own feathers and repelled by dissimilar colors. So far, there have been no studies on urban vs. rural differences in avian FIDs in response to different colored clothing. In this study, avian escape responses to observers wearing clothing of different colors with red (a bright color), black (dark color contrast), white (bright color contrast) and dark green (a concealment color) in urban (tropical Haikou city) and rural (Dongzhaigang Nature Reserve) populations were examined. Our results showed that urban avian FIDs were significantly shorter than rural avian FIDs. The colors of the observers’ clothing did not have a significant impact on urban avian FIDs. However, rural birds had significantly longer FIDs for observers in red than the other three colors, which impacted them negligibly. To our knowledge, this is the first study to report urban vs. rural differences in avian responses to the colors of observers’ clothing.

行为可塑性是在快速城市化的世界中促进人类与其他物种共存的关键因素。通常通过测量动物的飞行起始距离（FID）来估计动物的抗捕食能力。鸟类的FID受多种因素影响，包括观察者衣服的颜色。物种置信度假设认为，鸟类会被与其自己的羽毛相同或相似的颜色所吸引，并被不同的颜色所排斥。到目前为止，还没有关于不同颜色衣服对禽类FID的城市与农村差异的研究。在这项研究中，鸟类逃生对观察者穿着红色（亮色），黑色（暗色对比），研究了城市（热带海口市）和农村（东寨港自然保护区）人口的白色（明亮的对比）和深绿色（隐藏的颜色）。我们的结果表明，城市禽类的FID明显短于农村禽类的FID。观察者衣服的颜色对城市禽类FID的影响不大。但是，农村鸟类对观察者的FID明显长于其他三种颜色，这对它们的影响可以忽略不计。据我们所知，这是第一项报告鸟类对观察者衣服颜色反应的城市与农村差异的研究。观察者衣服的颜色对城市禽类FID的影响不大。但是，农村鸟类对观察者的FID明显长于其他三种颜色，这对它们的影响可以忽略不计。据我们所知，这是第一项报告鸟类对观察者衣服颜色反应的城市与农村差异的研究。观察者衣服的颜色对城市禽类FID的影响不大。但是，农村鸟类对观察者的FID明显长于其他三种颜色，这对它们的影响可以忽略不计。据我们所知，这是第一项报告鸟类对观察者衣服颜色反应的城市与农村差异的研究。