Swans are large, graceful waterbirds, and like their relatives the geese, they are mainly plant-eaters. Feeding them at the water's edge is popular, but the usual snack — bread — should be left at home.
What swans eat
Swans are largely herbivores. Their main food is aquatic plants, which they reach by dipping their long necks underwater and up-ending to graze the bottom. They also eat grasses on land, plus roots, grains and some algae, and will take the occasional small water creature such as an insect or snail.
Never feed swans bread
As with ducks and geese, bread is bad for swans. It fills them without nutrition, can harm young cygnets, and rots in the water where it spreads disease and encourages algae. Mouldy bread is especially dangerous. It is one of the most common but most harmful things people offer swans.
Better foods to feed swans
If you want to feed swans, offer foods close to their natural, plant-based diet: chopped lettuce and other leafy greens, defrosted peas and sweetcorn, and grains such as wheat or oats. Float small amounts on the water near the edge, give only what they will eat, and never leave piles to spoil.