Feeding Ducks and the Health of Water Bodies

Surrey Biodiversity Partnership

Position Paper Series

Feeding Ducks and the Health of Water Bodies

It is delightful to take the family to the local pond, lake or river to feed the ducks, and we encourage everyone to interact with and enjoy nature. There are several factors to bear in mind to make sure you protect wildlife when you go to the pond in the park.

What do Water Birds Eat in Nature?

Water birds forage for a range of food. Ducks will hunt for slugs, frogs and worms and their chicks will eat little flies and midges. Geese, coots and swans are herbivorous grazers and will eat grass, reeds and water plants. They appreciate having undisturbed grazing areas without dogs or chasing.

Bread, especially white, is not a good food for ducks and other water-birds. Bread is junk food for ducks, providing "empty calories" that do not meet nutritional requirements. Try buying floating duck food recommended by the RSPB.

What happens in Winter?

We come out in the fine weather and feed the ducks all through the summer. The extra food allows a larger population of ducks to establish at the site. When the weather turns bad and the free hand-outs cease the ducks are left with inadequate foraging from natural local sources and the population crashes dramatically.

Bread in the Water.

Uneaten duck food, plus extra faeces from the food eaten, result in unnaturally high levels of nutrition in the water. This results in high biological oxygen demand (BOD). High BOD encourages quick growth of bacteria. As the bacteria consume the nutrients they consume the oxygen. Low oxygen levels in the water mean that many water animals can not survive - Oxygen is the essential element for respiration. As bacteria break down they release nutrients back into the water creating eutrophic conditions and increasing algal growth. The algal blooms have a negative impact in choking water bodies and stopping sunlight penetrating to surviving water plants and organisms. If the algae populations die one can again go back to high BOD.

Whatever food you use make sure that you only throw in what is eaten immediately to avoid excess affecting the water quality.

Other Water Creatures and Water Nutrition Levels.

If a body of water has too many nutrients it will lose sensitive wildlife, especially the small invertebrate animals that the water birds depend on for natural food throughout the year. Ponds in Surrey have interesting mini-beasts such as water beetles, tadpoles of frogs and toads, and dragonfly larvae. Many of these species, some very rare, depend on low nutrient, clean waters.

Other Ways to Protect your Local Water Body

• Keep dogs well away from grazing water fowl and those with young chicks needing to sleep or feed.
• When boating keep your speed down on rivers to avoid washing away the bank. When banks erode habitat is lost and owners are prompted to shore up with inhospitable sharp sided solutions.
• If you maintain a river bank keep it shored up as naturally as possible and with plenty of emergent vegetation such as reeds.
• Try to feed ducks at times when food supplies are low such as Winter or even midweek.
• Check for and respect signs by the pond such as "Please do not feed the ducks".
• Throw food in bit by bit and check it is all eaten immediately.
• Remember if there is uneaten food in the water take your food home again.
• Try buying specially prepared floating duck and swan pellets. These are better for the birds and the pond environment, but should only be used when the birds are hungry enough to eat everything you offer them.
• You can pick a few handfuls of grass for swans, geese and coots (their natural food)- again do not tip in huge piles of grass clippings - only offer more when every blade is eaten.