Abstract

This study investigates how prey species, specifically Trinidadian guppies (Poecilia reticulata), cope with ecological uncertainty in predator-prey dynamics. Ecological uncertainty arises from conflicting and/or unreliable environmental cues, especially in ecosystems impacted by anthropogenic disturbances, which may directly influence prey decision-making and behaviour. This work explores how prey balance risk and safety in unpredictable environments, offering new insights into the adaptive strategies they use.
Chapter 1 looks at how conflicting safety and risk cues influence neophobia, the fear of novelty. The results show that guppies exposed to contradictory cues were more neophobic, exhibiting reduced movement, which supports the hypothesis that uncertainty leads to greater caution. Conversely, guppies conditioned to safety cues showed a preference for novelty, highlighting that they engage with new experiences when they feel that these are safe. These findings suggest that neophobia may be an adaptive response to environments where risk signals are unclear, particularly in areas disturbed by human activity.
Chapter 2 examines how anthropogenic disturbances contribute to ecological uncertainty which influence prey behaviour. Through field and lab experiments, it was found that guppies from high predation-risk and disturbed environments exhibited more caution and took longer to explore or return to disturbed areas. Guppies from low predation-risk environments, however, were more exploratory. This suggests that human disturbances increase uncertainty, driving prey to adopt more conservative, risk-avoidant strategies.
Ultimately, this study highlights how environmental unpredictability shapes risk-averse behaviours like neophobia. As human impacts on ecosystems continue to intensify, understanding ecological uncertainty is crucial for predicting long-term effects on biodiversity and ecosystem stability.