Carrion crows (Corvus corone) are a major depredating species of spring crops across European agroecosystems, especially during sowing, but limited effective non-lethal repellents are currently available. We assessed the deterrent effect of a bird-repellent seed coating, based on black pepper oleoresin (BPO) and applied to maize seeds, on free-ranging carrion crows. Using a standardized unique-choice test design in an urban context, we recorded the behavior of 45 ringed individuals exposed to natural, purple-dyed and purple BPO-coated maize seeds. Although color alone had no deterrent effect, BPO-coated seeds were largely avoided. Age-related differences in habituation emerged: younger birds (≤2 years) habituated to color cues over time, unlike older birds (≥3 years); all age groups maintained an aversion to BPO-treated seeds. Our results underscore the relevance of chemosensory repellents for persistent deterrence and offer a novel and replicable framework for pre-field testing of avian repellents. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.