The report Waterbirds in the UK 2006/7, published by the British Trust for Ornithology, names 12 sites in the South East as hosting internationally important numbers of waterbird species during winter or migration.

Langstone Harbour is one of just four internationally important sites in Hampshire, named for its wintering flock of dunlin. The harbour also has globally significant populations of dark-bellied Brent geese and black-tailed godwits.

Portsmouth Harbour is noted for its population of dark-bellied Brent geese, with a flock of more than 2,600.

A total of 143 sites across the UK are identified by the report as being of international importance for 43 species of waterbird.

The report identifies climate change, specifically milder winters, as being responsible for many birds shortening their migratory journeys and spending the winter in other countries closer to their breeding grounds.