WWT Slimbridge is a wetland wildlife reserve near Slimbridge in Gloucestershire, England. It is midway between Bristol and Gloucester on the eastern side of the estuary of the River Severn. The reserve, set up by the artist and naturalist Sir Peter Scott, opened in November 1946. Scott subsequently founded the Wildfowl & Wetlands Trust, which has since opened eight reserves around the country. Slimbridge comprises some 800 hectares (2,000 acres) of pasture, reed bed, lagoon and salt marsh. Many water birds live there all year round, and others are migrants on their ways to and from their summer breeding grounds. Other birds overwinter, including large numbers of white-fronted geese and increasing numbers of Bewick's swans.