Site Description
After Prescot Reservoirs, this is easily the top site in St Helens for birds, leaving the better known sites of Carr Mill Dam and Sankey Valley trailing over 50 species behind. The habitat is if anything even better than Prescot Reservoirs, though it does suffer a lot of disturbance from yachts, anglers and dog walkers, and this is probably the main reason why it doesn't quite get the number of species that the reservoirs does, or at least if it does get the species, they often don't stay as long.

The main feature of the site is obviously the mere itself, which is medium sized and has an island in the middle. The edges of the mere vary from sterile concrete to overgrown with Willow trees. There is a very small area of bulrushes. 

Adjacent to the mere on the west side is a large area of grassy fields, which are never cultivated, and have at times held either horses or more recently sheep. These fields become flooded in heavy rain, though a drainage ditch which was dug in the 1990's has "improved" the situation. A few pairs of Lapwings breed in these fields. Beyond the fields, to the west, is Prescot Reservoirs and further still Knowsley Safari Park, and there is often bird movements between the reservoirs and Eccleston Mere.

Most of the woodland is at the southern end of the mere, and this consists mainly of alders, with a few Ash and Sycamore trees. A stream enters the mere at the southern end, and this is always worth a look, because many of the best woodlands birds are seen here.

To the north west lies Catchdale Moss and the start of the Lancashire Mosslands.

Birds
Over 170 species of bird have been recorded at the mere. These include 18 species of duck, 18 species of wader and 11 species of gull.  However there is much more than just water birds to be seen, and 14 species of birds of prey have been recorded, including three species of owl. 

In winter, the alders around the mere can be alive with finches, with flocks of around 100 Siskins not unusual. The males glow yellow as Canaries in the winter sunlight. Linnets, Chaffinches and Goldfinches are also around in good numbers, with the occasional flock of over 100 of the latter. Bullfinches and Lesser Redpolls can be seen in small numbers. Also at this time of year, Yellowhammers, Tree Sparrows and Reed Buntings can be seen in small flocks, and in the winter of 1993/4 they were joined by a Little Bunting, the first Lancashire record since 1957.

Winter ducks include small flocks of Goldeneye, Pochard and Tufted Ducks, whilst Black and Red throated Divers, Red necked Grebe and Smew have all been recorded. Goosanders are seen in most winters.

The first sign of spring is usually the arrival of parties of Oystercatchers in February or March. Their piping displays compete with the Lapwings for the most evocative sound of the season, but unlike the latter, Oystercatchers do not breed at the mere. Shovelers begin to be seen, and pairs of Shelduck visit in the early mornings, searching for inland breeding sites. Migrants then begin to flood in and there is a remarkable consistency about their arrival dates. Sand Martins on the 24^th March, Swallow on the 2^nd April, Willow Warbler on the 9^th of April, House Martin and Common Sandpiper on the 11^th… the list goes on, and all these species and others, arrive within a day or two of the expected date.

Of the scarcer migrants, in May 1990 there was an incredible flock of around 50 Black Terns, but more often just one or two are seen. Osprey, Marsh Harrier, Reed Warblers, Yellow Wagtails, Whinchats, Pied Flycatchers and Redstarts are also seen occasionally, in very small numbers.

Spring blends into summer, and the resident species get down to the business of raising young, including up to 15 pairs of Lapwings, four pairs of Great Crested Grebes and sometimes a single pair of Kingfishers. This is the time of highest disturbance at the mere, but even so in 1997 breeding Teal, Gadwall and Tufted Duck joined the grebes and there can still be a few surprises. A party of four drake Common Scoters in June 1996 was one of the more unexpected.

Autumn begins in July, with a small passage of Common and Green sandpipers and a few Common terns, but generally Autumn passage is not as pronounced as that in spring, and often involves different species. Lesser Whitethroat, Spotted Flycatcher, Hobby, Tree Pipit, Greenshank and Arctic Tern are all typical birds of autumn migration, though none are annual.

October is one of the best months of the year, when a few Pintail and Wigeon visit, the Pochard flock begins to build up and winter thrushes can be seen in good numbers. Eccleston mere is also on the southern edge of the Lancashire mosses, the winter haunt of thousands of Pink footed Geese and skeins of variable numbers often fly over. Less certain is the presence of Whooper Swans on the mere, but they have been recorded.