Our national bird, the whooper swan (Cygnus cygnus), has also spread to Finland’s coastal bays. It nested in Vanhankaupunginlahti for the first time in 2014.
The pair of whooper swans nesting in Vanhankaupunginlahti have chased off all the mute swans (Cygnus olor) nesting in their visual range. On Lammassaari island, fights between whooper and mute swans have often led to the deaths of mute swans. Despite the fact that the mute swan is the heaviest bird found in Finland, at around ten kilograms, the whooper swan, which is lighter by several kilograms, regularly chases off mute swans from its nesting range.
The mute swan is an archipelago and bay species, but the whooper swan is now in the process of spreading to the same areas. The pair of whooper swans nesting in Vanhankaupunginlahti have not had any success raising their young in 2014–16, with the chicks disappearing within days of hatching, perhaps due to predators.
Whooper swans, photo Eero Haapanen.