Do ducks contribute to society

HGON Hess. Society for Ornithology and Nature Conservation e.V.

Duck moult

Where did all the drakes go?

A few weeks ago everything was "as always". Among the ducks on the moat in Ziegenhain or along the Schwalm there were just as many brightly colored drakes as there were inconspicuously patterned females. If you look at the animals, you have to realize: The drakes with their bright green head, dark brown breast and striking light gray body plumage have disappeared, there are only "brown ducks" on the way!

This observation, almost eerie at first glance, can be confirmed every year. The brightly colored males cannot be seen in July and August. But don't worry, the drakes are still there - they've got a magic hat, though. Anyone who observes the animals for a few weeks can see this for themselves: In May the drakes get their first brown feathers in the otherwise striking plumage, in June they are already predominantly brown and now in July and August they can hardly be distinguished from the camouflaged females. Only the year-round yellow beak distinguishes them from the females, who have an orange and dark patterned beak color.

Mallard drakes in camouflage, only distinguishable from females by their yellow beak. Photo: Stefan Stübing

 

The colouration of the drakes occurs during the moult, the conspicuous feathers gradually fall out and are replaced by the brown camouflage dress. In September the brown feathers of the so-called plain dress are gradually transformed back into the colorful, splendid dress. The drakes court the ducks in the winter half-year with the body adornment that is then again conspicuous, until the cycle begins again next May.

But why do drakes do this striking, double change of feathers when the production of each new feather is energy-consuming and almost all other birds moult only once a year? The reason is also due to moulting: Mallards, like all duck species, renew their flight plumage by “shedding” all wing feathers together within a few days. However, this makes them completely incapable of flight for some time. A colorful but flightless bird the size of a duck would be an invitation to a feast for any predator such as a fox or a bird of prey. Therefore, the drakes first camouflage themselves with a brown body plumage before they shed the wing feathers. After these have grown back, the body plumage is also changed back into the eye-catching splendor.

For many duck species, this flightless time also poses a problem in obtaining food. They therefore seek out what are known as moulting sites which, in addition to being safe from enemies, also offer sufficient food. These moulting sites meet the needs of the flightless animals so optimally that they are sometimes approached from distances of more than a thousand kilometers!

The entire European population of the shelduck is moulting on the North Sea coast in the area of ​​the Elbe estuary. Even the shelducks that breed in the Mediterranean fly there when they moult. The goosanders that breed in England, on the other hand, molt in a large fjord in northern Norway, while the Spanish red-crested ducks are drawn to Lake Constance.