Mallard Anas platyrhynchos

The Mallard is a common breeding species over most parts of Sweden. In winter, it is widespread over the southern part of the country occurring both on inland waters as far north as open water is available, showing a concentration to urban waters, also occurring in coastal areas, especially along the open coasts of south Sweden. 

The longterm trend for September was significantly but slightly decreasing for Swedish Mallards, whereas there was no significant trend for the last ten years, only fluctuations around a steady level. In the January indices both the longterm and short term trends were significantly increasing. As is seen from the diagrams the September and January indices for the Mallard show opposing trends over the series, January increasing and September decreasing. The increase in January indices is probably to a part a reflection of changes in the wintering distribution as a response to milder winters. It is on the other hand uncertain whether the decreasing trend in September reflects a decrease in the Mallard population or just is an effect of changed migration habits that leads to a decrease in the Mallard counts in south Sweden.

The winter population was estimated to be about 115,000 at the last country-wide surveys in 1988-89, being appreciably lower during an ice-winter. An increase in national midwinter indices indicate higher population levels during the mild winters of the 1990s, probably at least 150,000 individuals.

During the midwinter surveys in the seventies the coastal wintering population of Mallards was around 3000 but during the last two country-wide surveys in 2004 and 2015 78000 and 87000 Mallards were estimated to be present at the coasts. The total for the inland areas cannot be estimated as the species is wide-spread here on a large number of sites and the two winters were mild with a large spread of the species. The Mallard was fund wintering all over south Sweden (se map below) but with a concentration to the coasts. The large number of flocks in the Stockholm region on the other hand is an artefact coming from a large number os sites surveys here.

The Mallard population for Northwest Europe was considered to be more or less stable for the period 1976 - 2016, whereas the Swedish winter indices increased with 2.3% per year. This indicate a shift in the winter distribution in relation to milder winters.