Reed warblers are summer migrants closely associated with common reed, and the UK's most important cuckoo host species, breeding in reedbeds from May to August before migrating to West Africa.
Reed warbler welfare depends on access to mature, structurally complex reedbeds with clean water and abundant aquatic invertebrates for foraging. Fragmented or isolated reedbeds support fewer pairs and have lower breeding success. Reed warbler welfare is further affected by cuckoo parasitism, which results in loss of the entire breeding attempt.