THE ROBOTFALCON: A NEW METHODOLOGY TO STUDY PREY-PREDATOR INTERACTION AND AN INNOVATIVE BIRD DETERRENCE TOOL
Predation and predator–prey interactions are among the key processes shaping species traits and the functioning of ecosystems. Predators can influence prey through both lethal and non-lethal effects. The latter are less straightforward and therefore less explored than the former, yet they are expected to be of comparable, if not greater, importance in shaping prey adaptations. Birds, due to their complex anti-predator behaviours, are expected to be strongly influenced by non-lethal effects, such as fear-mediated shifts in distribution in space and time, camouflage, and escape behaviours or group responses. This thesis examines the anti-predatory responses of different bird species, at multiple levels of organisation and across different contexts, to the non-lethal threat posed by the RobotFalcon (RF), and tests its applicability as a deterrence tool. The RF is a predator-like fixed-wing aircraft resembling a peregrine falcon, which allows researchers to manipulate the predator component of predator–prey interactions, thereby overcoming several challenges typically associated with studying this interplay. Chapter I investigates how individual homing pigeons adjust their behaviour when exposed to a threat (i.e. the RF) along their stereotyped homing route. Under predation risk, individuals prioritise altitude adjustments over route changes, challenging predictions from the Landscape of Fear framework. Chapter II explores the interplay between individual- and group-level spatial responses in feral pigeons and greylag geese. The main findings highlight the role that individual personality may play in shaping group performance and behaviour, underscoring the importance of considering personality when studying collective dynamics. Chapter III assesses the effectiveness of the RF as a deterrence tool for two species that frequently come into conflict with human activities: the feral pigeon and the black-headed gull. The results indicate variable applicability of this method, likely linked to differences in resource value exploited by different species at different life-history stages and sites. By employing the RF as an ethological tool, this research introduces a novel experimental framework for studying predator-prey interactions and bird deterrence, contributing to both behavioural and ecological sciences.
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