Dress code for birds: attack frequency of birds to artificial larvae is mediated by clothing colour in urban green space

Understanding animal behaviour in response to human presence is crucial for developing effective measures to balance environmental development and conservation. In this study, we tested the Risk-Disturbance Hypothesis (RDH) and Human Shield Hypothesis (HSH) based on bird attacks on lepidopteran larvae in urban green spaces. We contend that clothing colour influences bird predation success and creates a spatial refuge for the prey. We found significant variations in attack frequency across clothing colour treatments vs the control (no decoy), indicating that shifts in urban predator-prey dynamics can be influenced not only by human presence but also by their visual prominence. Taken together, our findings provide evidence to support both the RDH and HSH. We further posit that these hypotheses are interrelated, as they explain how human activity shapes animal behaviour through risk perception and foraging decision-making. The RDH suggests that predatory birds perceive humans as risky and reduce their predation success in disturbed areas. In contrast, the HSH explains how prey benefits from this avoidance, creating a “human shield” that enhances prey survival. Our findings highlight the importance of well-thought-out urban design and wildlife management in mitigating potential negative human impacts on urban ecosystems, thus supporting biodiversity and maintaining critical ecosystem functions during urban expansion.