Five little ducks went swimming one day, over the pond and far away, mummy duck said "quack-quack -quack -quack" but only four little ducks came back. So runs the first verse of a nursery rhyme that my little grandson, who is mad on ducks, loves me singing to him.

Of course, being a nursery rhyme all ends happily for in the last verse, all the little ducks come swimming back. In real life however, it does'nt always work out like that for ducklings, goslings and indeed,all young birds are very vulnerable to predation in their first days of life.

When fishing as a boy, I watched as a brood of twelve mallard ducklings were dragged under by one or more pike. One second they were they were swimming, the next plop, gone. Two hours later only three ducklings remained.

Foxes, domestic cats, birds of prey, woodpeckers, squirrels and as far as water birds are concerned, herons pose a major threat. A few years ago at the London Wetland Centre a pair of avocets bred for the first time. The chicks duly hatched but only lasted for a few days, all taken by herons.

On a recent visit to the Wetland Centre on a day of driving rain and squalls, we saw twelve herons in a group, hunched up against the weather.

In mid-October, at the round pond in Kensington, a pair of Egyptian geese that normally breed as early as February, produced a family of goslings. No doubt the warm September influenced the late brood so hopefully, they will be advanced enough to survive the winter and predators intent on targetting them.