Eurasian bittern
Reed beds are one of the rarest habitats in the UK with only fifty greater than 20 ha. Marazion Marsh (16.8 ha) contains the largest reed-bed in Cornwall, the most westerly on mainland Britain and is an important reserve for breeding and over-wintering birds and passage migrants. The reed bed is managed for Eurasian bittern ("Botaurus stellaris") and is maintained by cutting the "Phragmites australis", removing dead litter and cutting back the invasive species such as willow ("Salix cinerea var atrocinerea"). The reserve also contains 3 ha of unimproved grassland, open water, woodland, willow scrub.