Whilst overwintering, Bewick's swans form very large flocks and mix with other swans (7). They tend to feed on roots and foliage, often in farmland during the day, and roost on the water at night (3) (7). Individuals can be identified by the unique patterns of the bill. Studies have shown that pairs stay together for many years and should one individual die it can take up to three years for the other to find a new mate (6). It has also been shown that family groups remain together and make the migration as a group (6). During the breeding season, pairs produce between 3 and 5 eggs which are incubated for up to 30 days. The young swans, known as cygnets, will have fully fledged after a further 40-45 days (3). They stay with their parents during the first winter and often during their second too, even if the parents have produced a new brood (7).