Crossness Nature Reserve

Crossness Nature Reserve is a small oasis within an industrialised urban environment, providing a unique opportunity to escape city life and enjoy one of the last remaining areas of grazing marsh within the Greater London area.

However the recent highlight has been a SQUACCO HERON, which took up residence in May 2007. There have also been sightings of a purple heron, and the first quail seen in the area for nearly 40 years. More details.

The reserve is part of the original Thames floodplain known collectively as the Erith Marshes. With much of the marshland having been developed to provide business and residential opportunities, the creation of Crossness Nature Reserve in 1996 secured part of this important, declining habitat for nature conservation and public access. As a result of the regionally important communities of wetland birds, plants and invertebrates, the site has been awarded Local Nature Reserve.

Thames Water, who own and manage the reserve, has undertaken a wide range of work to improve Crossness Nature Reserve for both wildlife and visitors. This has included the excavation of a wader scrape and the creation of a shingle island. During 2003 a little ringed plover reared one chick on this island, becoming the first successful breeding wader on the site since the early 1980’s.

The wader scrape can be viewed from a concrete bird hide that has been built into an earth bank, which can provide close-up views of species such as lapwing, common sand piper, greenshank and snipe. Adjacent to the wader scrape there is a newly constructed artificial sand martin wall, a bat cave and an artificial nesting cliff. These unusual structures have been constructed using reclaimed concrete pilings and other materials that were found in the surrounding industrial area.

From the bird hide, visitors can then explore the large reed bed. A pond-dipping platform and mini-beast area is also provided for educational visits. In order to minimise disturbance, the wader scrape complex and reed bed are contained within a ‘Protected Area’. This area is not open to the general public, but can be accessed by joining the ‘Friends of Crossness Nature Reserve Scheme’ (see below) and via other public open days and events. Through the ‘Friends Scheme’, members will be provided with newsletters providing regular updates on wildlife sightings and they will be invited to attend a number of community events and become involved in the active management of the site through survey and monitoring, leading guided walks and helping with practical conservation tasks.

Highlights: The reserve attracts good numbers of wintering wildfowl including teal, wigeon, gadwall and shoveler, in addition to typical species such as coot, moorhen, mute swan, grey heron and little grebe. The reed-fringed ditches on the reserve support a healthy water vole population and the wet meadow, managed by a prescribed horse grazing programme and a water level regime controlled artificially by a wind pump, provides a high tide roost for impressive numbers of lapwing, dunlin and redshank. At low tide, the mud flats of Halfway Reach Bay, which can be viewed from the sea wall, provide feeding grounds for huge numbers of wetland birds.

However the recent highlight has been a SQUACCO HERON, which took up residence in May 2007. There have also been sightings of a purple heron, and the first quail seen in the area for nearly 40 years. More details

The reed bed provides excellent breeding habitat for an impressive number of reed warblers and whitethroat. There is also a chance to view water rail, sedge warbler, willow warbler and reed bunting.
In total, over 130 different species of bird have been recorded at Crossness Nature Reserve, including little egret, sanderling, ring ouzel, Cetti’s warbler, marsh warbler, Dartford warbler, Temmick’s stint, wood sandpiper, blue-headed wagtail and red-backed shrike.

Flora: Important species of flora present at the reserve include knotted-hedge parsley and Borrer’s saltmarsh grass (species characteristic of closely grazed grassland), and marsh dock – a Kent Red Data Book species confined to the northwest Thames Marshes from Shorne to Erith. It is believed that Crossness may be this species’ most westerly distribution.

A number of rare aquatic and terrestrial invertebrates are present on the reserve. One Red Data Book 3 (RDB3) and five Nationally Notable B (NNB) water beetles were recorded in the ditches, and several RDB3 and NNB terrestrial invertebrates were recorded from the ditch margins. Within the reedbed, four NNB and four regionally notable (London) invertebrates are present, as well as a RDK3 moth – the twin-spotted wainscot – a reedbed specialist with larvae that feed internally on reed stems. A NNB leaf hopper and chrysomelid beetle were recorded in a survey of the ungrazed grassland, alongside Roesel’s bush-cricket which is common in the Thames Estuary but extremely rare or absent from the rest of the UK.