Predation experiments with 3D-printed lizard models yield limited responses in pheasants

Animal colouration has been viewed as an adaptation shaped by both abiotic and biotic factors, balancing sexual attractiveness against predation risk. In studying predator-prey dynamics, using 3D models as prey surrogates is common, but material constraints can affect outcomes in both natural and seminatural settings. Here, we utilized 3D-printed models representing three colour morphs of sand lizards (Lacerta agilis) to investigate interactions with captive-bred pheasants (Phasianus colchicus) utilizing forced exploration experiments in an outdoor arena fitted with a grass carpet. The models adequately represented the lizard colouration across a reflectance spectral range of 330-800 nm. Our findings indicate that the pheasants generally exhibited a minimal response to static models, with significant differences observed only in younger birds (7-12 weeks old), demonstrating a higher alert response than adults. No effects were found relating to the colour morph or sex of the lizard models. These results suggest that immobile 3D-printed prey models may be insufficient to trigger natural predator responses in this predator-prey system, highlighting potential limitations of static models in eliciting predator reaction.