title: Social transmission of a host defense against cuckoo parasitism.
abstract: Coevolutionary arms races between brood parasites and hosts involve genetic adaptations and counter-adaptations. However, hosts sometimes acquire defenses too rapidly to reflect genetic change. Our field experiments show that observation of cuckoo (Cuculus canorus) mobbing by neighbors on adjacent territories induced reed warblers (Acrocephalus scirpaceus) to increase the mobbing of cuckoos but not of parrots (a harmless control) on their own territory. In contrast, observation of neighbors mobbing parrots had no effect on reed warblers' responses to either cuckoos or parrots. These results indicate that social learning provides a mechanism by which hosts rapidly increase their nest defense against brood parasites. Such enemy-specific social transmission enables hosts to track fine-scale spatiotemporal variation in parasitism and may influence the coevolutionary trajectories and population dynamics of brood parasites and hosts.
authors.affiliation: Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. n.b.davies@zoo.cam.ac.uk
authors.forename: Nicholas B
authors.initials: NB
authors.lastname: Davies
authors.forename: Justin A
authors.initials: JA
authors.lastname: Welbergen
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001717:Birds; D005260:Female; D007858:Learning; D008297:Male; D009425:Nesting Behavior; D010311:Parrots; D012919:Social Behavior; D020308:Songbirds; D013731:Territoriality; D006113:United Kingdom; D014828:Vocalization, Animal