2 November 2009
Mallards start to pair up in October and November, and begin nesting in March.
They prefer to nest near water. The female generally makes her nest in a place well covered in vegetation or in a natural hole in a tree. Mallards exploit any open water where food is plentiful, however, and this sometimes results in the choice of less than perfect nest sites, particularly in towns...
Nests have been found in boathouses, wood piles, old crow's nests, hay stacks, roof gardens, enclosed courtyards and even in large flowerpots on balconies several floors up!
Town ponds with an abundant and reliable food supply often attract more mallards than are able to nest close by. In these situations, many female mallards nest well away from the pond to avoid competition and harassment from others.
Encouraging and deterring nesters
Most people welcome ducks nesting in their garden. They often choose parts of a garden where the vegetation provides them enough cover in which to conceal the nest. It is worth having a well-stocked flowerbed or shrubby border, or leaving a corner of your garden to grow wild to provide them with good nesting habitat.
The female should be able to find food for herself while she incubates, but you could put out a bowl of drinking water, together with duck pellets and cooked potatoes for her to eat. Put these in an accessible area some distance from the nest.
It is normally not practical to prevent ducks nesting in a garden. They are very secretive about a nest, and so if you see a pair of ducks hanging around, the chances are that they are already nesting. Because of the legal protection ducks and their nests receive in all parts of the UK, do not be tempted to chase away a duck that comes into your garden in the spring, because she must be allowed access to her nest. If you have a pond but do not want it to attract nesting ducks into your garden, make sure you cover the pond before the breeding season starts. Although ducks may still nest, without access to water, they will be less likely to stay in the garden after the ducklings hatch.
The female mallard builds a nest from leaves and grasses and lines it with down plucked from her breast.
Eggs are laid between mid-March and the end of July. The normal clutch is about 12 eggs, laid at one to two day intervals. After each egg is added, the clutch is covered to protect it from predators. If you find a nestful of duck eggs, leave it well alone – it is unlikely to have been abandoned.
The laying period is very stressful for the female – she lays more than half her body weight in eggs in a couple of weeks. She needs a lot of rest and depends heavily on her mate to protect her and their feeding and loafing areas.
End of the pair bond
The role of the male is almost over once the clutch is laid. He remains sexually potent for a while in case a replacement clutch is needed, but gradually loses interest and joins other males to moult. At this time, groups of males with no obvious duties often mate forcibly with females that appear to be unattached. This anti-social phase is short-lived and ends once moulting is underway.
Mallards and the law
Mallards and their nests are protected by the Wildlife and Countryside Act 1981, which makes it an offence to intentionally kill, injure or take any wild bird, or to take, damage or destroy its nest, eggs or young.
Therefore, it is important not to chase away a duck that has started nesting, since she must be allowed access to her nest. If you find a nest full of eggs, you must not interfere with them. A failed nest can be cleared and remaining eggs destroyed later in the year, once it is absolutely certain that nothing will come of the contents.