The clear water but small area of Myllylähde offers scant opportunity for waterbirds to thrive. However, the goldeneye belongs to the pochards (diving duck) family and already on the cusp of spring goldeneye pairs can be observed in impressive courtship displays as the ice begins to melt. The mating season begins in winter and continues until April, after which the female seeks a natural or man-made nesting place in which to lay 6-12 light green eggs. In modern woodland there are only few suitable nesting sites, thus the same nest can be used by more than one female. A female will hatch all the eggs in the nest irrespective of their parentage.
Goldeneye chicks hatch almost simultaneously and roughly 24 hours after hatching, the chicks will leave the nest to dip their webbed feet in water. The chicks feed on their own from the first moment and the mother does not feed them at all. The diet of both chicks and adults is made up of small benthic animals such as gastropods, insect larvae and crustaceans. Myllylähde can support up to five broods and other broods will probably use ditches to go downstream to Lake Pyhäjärvi. The mother will leave the chicks when they have gained the ability to fly and can move to larger waters prior to migrating. Broods can disperse but individual chicks can remain at the spring even until the ice comes. Myllylähde’s goldeneyes are accustomed to the presence of humans but the broods move to the higher pond’s other side when people arrive.
Goldeneye females are very faithful to a nesting site and if it keeps its shape, they will use the same one from one year to the next. The same fidelity does not necessarily apply to males because females may change their partners over the years. Also, not all members of a brood will necessarily have the same father. The male’s role in the relationship is fertilize the female. When a female has laid eggs, the male can fertilise other females as well. After the females have been fertilised, the males will leave the nesting area and spend their summer in each other’s company.
Photo: Jyrki Oja