Lymm dam has a varied cross-section of wildlife. There is something of interest around the site throughout the seasons
Much of the lake is enclosed by woodland, the canopy species being mainly oak, beech, ash and sycamore. The tall Lombardy poplars along the eastern and western edges of the site are a legacy of Lord Leverhulme's planned housing scheme. The semi-mature woodland along the bridleway, below the poplars, is self-seeded, as is that on the eastern side of the Upper Dam. These areas were once subject to mowing/ grazing, but began to develop their own woodland cover when these activities stopped in the second half of the 20th century. The youngest woodland areas at Lymm Dam are those planted by the Ranger Service with local school and community groups since the mid 1980s. Some 12,000 young trees have been planted, usually to provide an understory or increase the area of existing woodland.
Lymm Dam blossoms with a wide array of wildflowers. The dam looks very different across the seasons as a kaleidoscope of different colour flowers appear. Species growing in woodland areas include lords and ladies, wild garlic, wood anemone, herb bennet, dog's mercury, lesser celendine and wood sorrel. In damp and marshy areas marsh marigold, bittercress and water mint grow. In meadows and on sunny banks, wild flowers include meadow cranesbill, tormentil, lady's bedstraw and meadowsweet.
A number of mammals make their home at Lymm Dam, though most of them are very secretive and elusive. One which is very conspicuous however, is the grey squirrel. The grey squirrel is not native to the British Isles, having been introduced from North America in the 1850s. The animal thrived in British woodland and its competitive and sometimes aggressive nature pushed the native red squirrel out of its traditional territory. Grey squirrels will strip the bark from some trees to get at the sap underneath and the animal is regarded by many as a pest.
Perhaps the most interesting mammal activity at Lymm Dam is the area's bat population. On a warm summer evening there are many bats on the wing over the meadows and the lake itself. The majority are pipistrelles, Britain's smallest and most common bat, but Daubenton's (Britain's smallest) and noctules (Britain's biggest) are also present. To really appreciate the level of bat activity, a detector needs to be used, although some creatures can be seen with the naked eye. Try looking around tree top height over the meadows on the eastern side of the lake shortly after sunset.
Lymm Dam's variety of habitats means that there is an impressive array of bird species. Nuthatch, treecreeper and lesser spotted woodpecker can be seen in woodland areas, whilst herons are a common sight fishing in the shallow waters of the Upper Dam. Kingfishers nest in the banks over the Main Dam and can frequently be seen streaking low over the water as they return to the nest with food for their offspring.
The lake itself is home to several species of wildfowl. Mallard, coot, moorhen and great crested grebe are all resident and several tufted ducks spend each winter here. Occasional visitors include Canada geese, mandarin, teal, muscovy and pochard. The grebes are particularly watchable in springtime for their elaborate courtship display. Notice also how young are carried round on their mother's back for the first few days after hatching.If you enjoy bird watching have a look at Lymm Ornithology Group