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Restoring habitats at Eelmoor Marsh

April 16, 2024

Przewalski horses grazing at Eelmoor Marsh

The rare species at Eelmoor Marsh SSSI, our lowland heath restoration site, experienced a remarkable year in 2023. In particular, there was a notable increase in the populations of Dartford warbler Curruca undata, with the number of breeding territories rising from two in 2018 to eight in 2023, the highest record on site since systematic counts began in 2023. 

The Dartford warbler, a protected ground nesting species, is dependent on the healthy, mature gorse found on lowland heath to build their nests. While populations crashed in the 1960s, they have been gradually recovering since. Their success at Eelmoor is largely attributed to the removal of elderly gorse from the dry heath, which is carried out as part of the winter habitat management works on site. 

A view of Eelmoor Marsh, Site of Special Scientific Interest

Images: Paul N Drane (Eelmoor Marsh landscape and Przewalski’s horses above)

The positive impacts of management extend to other species, such as the nightjar Caprimulgus europaeus, another protected heathland species that has found a stronghold at Eelmoor. In 2023, four territories were found, up from three in 2022. This was also an excellent year for the sand lizard Lacerta agilis, evidenced by the discovery of ten test burrows and five sightings, including one female seen digging to lay her eggs. Population monitoring of this species can be difficult, but evidence of breeding is a promising sign. 

Volunteers from QinetiQ Farnborough played a vital role in enhancing the sand lizard habitat by scraping back the soil and clearing overgrown vegetation, exposing the sand underneath. As their name suggests, the lizards rely on this to bask, dig burrows, and lay their eggs. 

Long-term ecological monitoring at the marsh has allowed us to identify species of concern and tailor our management practices accordingly. Continued habitat management efforts in 2023 focused on creating favourable conditions for dragonflies and damselflies, encouraging certain plant colonies, and creating bare ground for target species such as woodlark Lullula arborea.  

In order to do this, overgrown scrub was removed to prevent it from encroaching onto the heathland, Scots pine Pinus sylvestris and silver birch Betula pendula were felled to reduce shading of waterways, vegetation was mown to diversify the age and structure, and ditch edges were strimmed to help existing populations of rare butterworts Pinguicula vulgaris and Pinguicula lusitanica, among other key plants.  

Using machinery, we also scraped back turf to encourage new species growth, cleared and dammed ditches to enhance wetland habitat, and created and restored pools to provide more open water. We hope that the work carried out this year and in previous years will have positive impacts for the incredible wildlife we have here and reflects our ongoing dedication to Eelmoor Marsh’s unique biodiversity. 

Marwell Wildlife is felling trees at Eelmoor Marsh
A JCB at Eelmoor Marsh