Should I feed swans?
Offering swans food is not recommended.
For many people, feeding swans at the local park or waterway is an enjoyable way of interacting with wildlife. Offering food to waterfowl is a social activity that is often undertaken as a family.2 However, feeding non-natural sources of food can lead to nutritional imbalances, increase the risk of disease and lead to altered animal behaviour.
Bread is often a favourite choice for feeding waterfowl. However bread is like junk food and provides little nutritional value for swans. Too much can lead to nutritional imbalances and life threatening complications. A condition called ‘angel wing’ has been attributed to artificial diets, which results in birds being unable to fly. 3 Black swans (Cygnus atratus) are vegetarian feeding on algae and weeds which they obtain by plunging their long necks in up to 1m of water.4
Remember birds are much smaller than humans so even small portions of human food can be very unhealthy for them.
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Spread of disease
When too much bread is offered to waterfowl it is not eaten. The leftover bread sinks causing nutrient pollution, which in turn leads to an increase in the soil bacteria that causes avian botulism. While there is no direct link between feeding bread to birds and botulism, it can add to conditions which make birds sick.4 When water levels are low, the bacteria are concentrated, which causes infection when swans are plunging for food. Swans with botulism become paralysed, unable to eat and drown.
Disrupting animal behaviour
Further research is needed to assess whether feeding swans can cause them to become dependent on humans for food or abnormally increase the local population density. There have however been anecdotal reports of aggressive behaviour by swans demanding food. This can put young children at risk who are often feeding these birds.
Feeding swans is not recommended.
However, if you must feed them, you should aim to minimise the risk of harm:
- Completely avoid unhealthy (and potentially life-threatening) foodstuffs such as bread and other baked goods.
- Offer small portions of safer foods, and not everyday.
- Shredded lettuce, corn and peas are a safer option for vegetarian birds such as swans.
- Offer food in a way that minimises the risk of harm.
- Stop feeding if the swans are not eating food.
Download the ‘Swan feeding’ information sheet.
1 Nagy, K.A., Girard, I.A., Brown, T.K. 1999. Energetics of free-ranging mammals, reptiles and birds. Ann. Rev. Nutr. 19: 247-277
2 Chapman R. & Jones D.N. (2009), Just Feeding the Ducks: Quantifying A Common Wildlife-Human Interaction, The Sunbird Vol 39 No. 2, 19-28.
3 Kear J. (1972), Notes on the nutrition of young waterfowl, with special reference to slipped-wing.