Red-backed Shrikes (Lanius collurio) adjust the mobbing intensity, but not mobbing frequency, by assessing the potential threat to themselves from different predators

Abstract

We tested ability to adjust nest defence in the red-backed shrike. We presented dummies of three species of adult bird predators (sparrowhawk, kestrel, and long-eared owl; differing in the potential danger for the defending birds), plus two species of nest predators (jay and magpie; differing in the proportion of nestlings of small passerines in their diets). A dummy pigeon was used as the control. Shrikes regularly attacked all of the dummies tested, with the exception of the magpie and pigeon.