Female common cuckoo calls dampen the mobbing intensity of great reed warbler hosts (Marton et al. 2021, Ethology)

To test whether the female cuckoo's bubbling call has a negative effect on host mobbing intensity, we performed experimental trials at great reed warbler nests (n = 61), during the laying and early incubation stages, by placing 3D‐printed common cuckoo or dove models at the nest.We recorded the mobbing behaviour of great reed warblers for 2 min upon discovering the cuckoo or dove decoy, after which we played back the female cuckoo's bubbling calls for the cuckoo decoy, or the call of the dove for the dove decoy. We subsequently counted the number of adult great reed warblers present during the trial and the numbers of different mobbing behaviours separately: “churr” alarm calls, bill snaps, pecks and physical contact attacks against the decoys per the 2‐min trials.