The effects of daily weather variation on foraging and responsiveness to disturbance in overwintering Red Knot Calidris canutus

We studied Red Knot Calidris canutus foraging on intertidal mudflats that were subject to attacks by Peregrine Falcons Falco peregrinus. Foraging rate and position with respect to cover that a predator might use was unaffected by weather, but responsiveness of Red Knots to predators and other disturbances increased with both windspeed and air temperature. These results are interpreted within the framework of birds seeking a strategy that minimises the sum of mortality risks from predation and starvation. We also found that foraging success (measured as the probability that a probe in the substrate yields an observed food item) increased with an increase in temperature.