In severe winters a few birds are found dead, and a few feathers or mangled remains show us where a wood-pigeon or some other bird has been destroyed by a hawk, but no one would imagine that five times as many birds as the total number in the country in early spring die every year.

No doubt a considerable proportion of these do not die here but during or after migration to other countries, but others which are bred in distant countries come here, and thus balance the account.
Again, as the average number of young produced is four or five times that of the parents, we ought to have at least five times as many birds in the country at the end of summer as at the beginning, and there is certainly no such enormous disproportion as this.

The fact is, that the destruction commences, and is probably most severe, with nestling birds, which are often killed by heavy rains or blown away by severe storms, or left to die of hunger if either of the parents is killed; while they offer a defenceless prey to jackdaws, jays, and magpies, and not a few are ejected from their nests by their foster-brothers the cuckoos.

As soon as they are fledged and begin to leave the nest great numbers are destroyed by buzzards, sparrow-hawks, and shrikes.

Of those which migrate in autumn a considerable proportion are probably lost at sea or otherwise destroyed before they reach a place of safety; while those which remain with us are greatly thinned by cold and starvation during severe winters.