A FEW days ago I was travelling slowly down the Grand Canal in my boat when a female mallard appeared out of a reed bed a few metres in front of the bow.
She appeared to be injured, flapping her wings wildly, straining her neck forward, splashing and barely managing to keep in front of the boat. This continued for 50 or 60 metres and then she made a miraculous recovery, took off almost vertically and flew back to the reed bed she had emerged from.
She was, of course, faking it. Back in the reed bed was a little group of newly hatched ducklings under strict instructions to keep quiet and remain hidden while mother lured a strange predator away by pretending to be easy prey. This trick is a survival strategy that is used by many species of wild duck around the world. A few other bird families do it too. A female lapwing once tried it out on me.
Female mallard have large broods, laying up to 13 eggs. Occasionally the clutches are even larger because a certain amount of brood parasitism goes on — lazy females, either mallards or other duck species, deposit their eggs in a nest belonging to someone else in order to avoid the chore of rearing their young.
The nests are sited on dry land, often at some distance from the water, in a site safe from predators. They are normally on the ground but sometimes in a tree, on a roof or even in window box on a high apartment building. The moment the last duckling has hatched the mother takes them to the water. The ducklings can’t fly and if the nest is a high one they have to jump, or be pushed. They are very light and fluffy so they can survive a drop of many metres.
But the journey to the water is a dangerous one because predators are attracted to the vulnerable little birds. Crows, gulls, herons and magpies are a particular danger and the brood is often much smaller by the time it reaches the water’s edge.
Here the female waterproofs the surviving ducklings, using her beak to coat them in preen oil from her own preen gland, just above her tail. They can swim fast and well and dive under water so the canal, particularly if there’s thick bank-side vegetation to hide in, is the safest place for them. Pike take ducklings, and so do mink. There are still herons lurking in the reed-beds and an opportunistic rat will kill a small duckling. It’s obvious why the female has to lay so many eggs in order for the population to remain stable.
Mallard are what are called dabbling ducks, as opposed to diving ducks, because they mainly feed on the surface. But they can dive and swim under water for some distance to escape danger. They are supremely adapted to the aquatic life, partly thanks to their large, webbed feet. These contain no nerves or blood vessels, which is why the ducks can survive in extremely cold water, or even stand for hours on ice, without chilling down.
The feet are vital not only for swimming and walking but also for flying. A mallard’s ability to take off almost vertically is not just because of its strong wings. It gives itself a boost by pushing down strongly with its feet at the moment of take off. When it’s landing it will spread its toes and point its feet forward so that the webs act like air-brakes to slow it down.
Although they’re water birds they sometimes spend a lot of time on land, gleaning stubble fields far from the water at harvest time, for example.
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