Animated images: a new tool to study visual communication. (#637)
Investigating the role of visual information in animal communication often involves the experimental presentation of live stimuli, mirrors, dummies, still images, video recordings or computer animations. In recent years computer animations have received increased attention, as this technology allows the presentation of moving stimuli that exhibit a fully standardized behaviour. However, whether simple animated 2D-still images of conspecifics and heterospecifics can elicit detailed behavioural responses in test animals is unclear thus far. In this talk we will present (i) results from a validation study to show that Neolamprologus pulcher, a cooperatively breeding cichlid, is able to differentiate between images of conspecifics and heterospecifics (ii) results from three experiments to illuminate the influence of early and current social environment as well as the influence of early predator exposure on anti-predator behaviour. We confirm that even simple animated images, which can be produced with minimal technical effort at very low costs, can be used to study detailed behavioural responses. By applying this technique we were able to show that vigilance is influenced by the current social environment as well as by early predator exposure but not by a variation in early social environment. Test fish engaging in territory defence with social companions detected an animated predator later than single housed fish. In contrast, the exposure to predators during early life increased vigilance and decreased the ability to differentiate between a dangerous predator and a harmless herbivore. This shows that current social environment distracted individuals leaving them at higher risk, whereas early predator exposure might prepare individuals for a dangerous environment later in life. In conclusion, animated 2D images are a powerful tool to study behaviour and by using this technique we were able to show that current social environment and early predation threat are important factors shaping key aspects of anti-predator responses.