Sir: When the disappearance of songbirds is discussed, why is the balance between them and their natural predators so seldom considered? Factors such as loss of habitat that cause the birds to decrease act only indirectly on their predators.
Our leafy suburb is a relative haven for wildlife. When I moved here 29 years ago, our garden regularly harboured scores of sparrows, two pairs of robins, numerous wrens and always at least two blackbirds and a pair of songthrushes. It was visited by many other species of small birds such as flycatchers, finches and tits. The only small birds that I see regularly now are blue tits. We have a nesting box which they use every year.
In this area we now have foxes, numerous crows, jays, magpies and a pair of kestrels. I sometimes hear screams at night and in the morning find a heap of feathers on the grass where a fox has been. Of the song thrushes that have tried to live here in recent years, the last ones, two years ago, nested in ivy on a tree and had their nest pulled out by a crow.