Semi-intensive Shrimp-Farms as Experimental Arenas for the Study of Predation Risk from Falcons to Shorebirds

Varying environmental conditions and energetic demands can affect habitat use by predators and their prey. Anthropogenic habitats may provide an opportunity to document both predation events and foraging activity by prey, and therefore enable an empirical evaluation how prey cope with trade-offs between starvation and predation risk in environments of variable foraging opportunities and predation danger. Here we use seven years of observational data of peregrine falcons Falco peregrinus and shorebirds at a semi-intensive shrimp-farm to determine how starvation and predation risk vary for shorebirds under a predictable variation in foraging opportunities. Attack rate (mean 0.1 attacks/hr, equating 1 attack every ten hours) was positively associated with the total foraging area available for shorebirds at the shrimp-farm throughout the harvesting period, with tidal amplitude at the adjacent mudflat having a strong non-linear (quadratic) effect. Hunt success (mean 14%) was higher during lo...