Animated images as a tool to study visual communication: a case study in a cooperatively breeding cichlid

Abstract

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 conspecific and heterospecific stimulus animals can elicit detailed behavioural responses in test animals is unclear thus far. In this study we validate a simple method to generate animated still images using PowerPoint presentations as an experimental tool. We studied context-specific behaviour directed towards conspecifics and heterospecifics, using the cooperatively breeding cichlid Neolamprologus pulcher as model species. N. pulcher did not only differentiate between images of conspecifics, predators and herbivorous fish, but they also showed adequate behavioural responses towards the respective stimulus images as well as towards stimulus individuals of different sizes. Our results indicate that even simple animated still images, which can be produced with minimal technical effort at very low costs, can be used to study detailed behavioural responses towards social and predatory challenges. Thus, this technique opens up intriguing possibilities to manipulate single or multiple visual features of the presented animals by simple digital image-editing and to study their relative importance to the observing fish. We hope to encourage further studies to use animated images as a powerful research tool in behavioural and evolutionary studies.

Validation of 2D‐animated pictures as an investigative tool in the behavioural sciences: A case study with a West African cichlid fish, Pelvicachromis pulcher

“…We produced PowerPoint© exemplar animations of predator (Experiment 1) and conspecific male specimens (Experiment 2) following the protocol of Fischer et al. (). Parachanna obscura ( N = 4 exemplars, ± SE total length = 19.1 ± 0.3 cm) and P. pulcher individuals ( N = 6, ± SE total length = 5.7 ± 0.0 cm) were photographed under standardised light conditions using a Nikon D80 digital camera with a Nikon AF‐S DX Nikkor objective.…”

“…Furthermore, live stimuli vary naturally in their behaviour (e.g. activity and position within and between trials; Fischer et al., ), making it difficult to ensure equal conditions for all test individuals; in contrast, virtual stimuli can be standardised.…”

“…Furthermore, videos and animations are often limited to presenting solely visual cues, even though olfactory, chemical or acoustic cues are important in animal behaviour and individual recognition (Baldauf et al, 2008;Balshine-Earn & Lotem, 1998;Hesse, Anaya-Rojas, Frommen, & Thünken, 2015). Another limitation of the use virtual stimuli is that they usually do not allow for interactions with test individuals (Fischer et al, 2014; but see Butkowski et al, 2011 for an interactive approach).…”

Animals in Virtual Environments

“…Computer generated content through projector or screen Fish -Mate preference [4,46], Predator Response [34,42], Communication [39]. Review - [11,86] Stimulus programmable, reusable setup, semi-interactive or rule based interaction, can display abstract stimulus.…”

“…Virtual stimuli were proposed as an alternative to other screen-based methods and this method has been widely adopted for studying different behavior patterns (fish) e.g. mate preference [4,46], predator response [34], and visual communication [39]. New methods have been employed to create realistic animals and scenes.…”