Alarm calls evoke a visual search image of a predator in birds

Significance In human speech, words often cause listeners to retrieve visual mental images of target objects. In nonhuman animal communication systems, many key, language-like features have been demonstrated, but there is still no evidence that animal signals evoke mental images of objects in receivers. Japanese tits produce specific alarm calls when encountering a predatory snake. Here, I show that simply hearing these calls causes tits to become more visually perceptive to objects resembling snakes (moving sticks). This result indicates that before having detected a real snake, tits retrieve its visual image from snake-specific alarm calls and uses this to search out snakes. This study provides evidence for a call-evoked visual search image in a nonhuman animal. One of the core features of human speech is that words cause listeners to retrieve corresponding visual mental images. However, whether vocalizations similarly evoke mental images in animal communication systems is surprisingly unknown. Japanese tits (Parus minor) produce specific alarm calls when and only when encountering a predatory snake. Here, I show that simply hearing these calls causes tits to become more visually perceptive to objects resembling snakes. During playback of snake-specific alarm calls, tits approach a wooden stick being moved in a snake-like fashion. However, tits do not respond to the same stick when hearing other call types or if the stick’s movement is dissimilar to that of a snake. Thus, before detecting a real snake, tits retrieve its visual image from snake-specific alarm calls and use this to search out snakes. This study provides evidence for a call-evoked visual search image in a nonhuman animal, offering a paradigm to explore the cognitive basis for animal vocal communication in the wild.