The mallard (Anas platyrhynchos) became tame and dependent on humans in Helsinki in the 1930s. At the time, the City of Helsinki granted funds for the winter feeding of mallards in Töölönlahti. As a result, tame mallards soon started nesting on many of the city’s shores.
The mallard can nest by almost any water body, from small streams to the outer archipelago. It is very diverse in its choice of nesting site. The majority of mallard nests are built on the ground, but it can also nest in large tree hollows, in crow’s nests or in boxes in balconies.
Some urban mallards nest very early in the year, with broods appearing as early as May Day. However, some mallard broods don’t hatch until July. These late hatchers are never second broods, but rather new attempts after destroyed or abandoned clutches.
Mallard nests are regularly raided by crows and magpies. This often happens after the mallard mother has been scared away from her nest, exposing the eggs. If you happen to come across such a nest, you can try covering the eggs with down from the nest in order to conceal them from would-be egg thieves.