The 250km (155 mile) coastline of the Solent is distinctive and dynamic. It has a wide range of habitats from the sandy beaches at Ryde and the shingle bank of Hurst Spit, to the vast natural harbours of Chichester, Langstone and Portsmouth. This makes the Solent one of the most important places in western Europe for birds. On a typical winter day there are over 90,000 birds along the shore. This includes internationally important numbers of eight species, and nationally important numbers of a further eight. Many more birds pass through on their migration routes from the Arctic and Scandinavia to the Mediterranean and Africa.
For these reasons, three areas of the Solent have been designated as Special Protection Areas (SPAs) by the government. Three areas are also designated as wetlands of international importance under the Ramsar Convention (an international treaty for the conservation and sustainable use of wetlands).
The Solent is sheltered by the Isle of Wight and has a complex double tide making it unique. The birds use the many and varied natural habitats in different ways. An area can only support a certain number of feeding or roosting birds, so the patchwork of different habitats across the Solent is vital.
Mud may look devoid of life to the human eye, but is full of plant life and small creatures. Many wading birds have long bills, which they use to probe the mud and feed on the worms and crustaceans below. Ducks and geese have broad bills, which they use to strain out small animals, insects and plants from the mud. At high tide the mudflats are covered over and the birds move onto the shore to rest or feed elsewhere.
These grassy areas are frequently flooded by salt water, so are home to many unique plants and animals which can't be found anywhere else. Birds feed on the plants and insects but also roost here at high tide when the mud flats are covered over. When the tide is very high even the saltmarshes are covered by water and the birds need to find other places to rest.
Grazed meadows on the coast are often flooded so are rich with grass, other plants, and invertebrates. Ducks and geese feed on the short grass here during the winter. Waders are able to probe in the mud for invertebrates. During high tide the birds will use these areas as refuges to rest. They like wide open spaces so they can easily spot predators.
The birds feed on mudflats and saltmarshes during low tide; at high tide they move on to the shore to rest. These resting places are known as high tide roosts, which can be shingle, marsh or even fields.