Country: Nature Notes

FOR THE past couple of weeks, pairs of magpies have been squabbling to establish territories, and now they are hard at work building nests. They take elaborate safety precautions, carefully choosing sites in thick thorn bushes or in the tops of high trees.

A bird's nest is an amazingly strong structure: the cup, in the centre of a mass of sticks, is lined with dried mud, and a dome of twigs raised above it protects the sitting hen from predators such as peregrine falcons.

Each bird generally lays four or five eggs, green mottled with brown, but research has shown that, the better the territory, the larger the clutch is liable to be.

Magpies rob the nests of smaller birds, taking the eggs and chicks in order to feed their own broods. But the British Trust for Ornithology points out that magpies are only seasonal predators, and claims that, although their numbers have trebled over the past 20 years, they are not to blame for the general decline of songbirds in this country.

Their population increase is due - at least in part - to the fact that such a great number of wild animals and birds are killed on the roads: accidents provide them with fresh carrion every single day of the year.