Egyptian Goose
Alopochen aegyptiacus

As the name suggests, Egyptian Geese are native to Africa, from along the Nile through to the bottom of South Africa. They were introduced in the 1700s to Britain for ornamental ponds and quickly escaped and began breeding in the wild. These are large birds at 63-73 cm in length and are closely related to the shelducks. They form pair bonds for life and can be very territorial when breeding.
 

1-2 Sandhurst Balancing Pond, Berkshire, 06/06/2006.