multitude recrosses the Channel into England, coming by way of France
and Spain from north or south or mid-Africa and from Asia, they at once
proceed to disperse over the entire country from Land's End to Thurso
and the northernmost islands of Scotland, until every wood and hill and
moor and thicket and stream and every village and field and hedgerow and
farmhouse has its own feathered people back in their old places. But
they do not return in their old force. They had increased to twice or
three times their original numbers when they left us, and as a result of
that great adventure a half or two-thirds of the vast army has perished.

The instinct which in character comes nearest to that of the parent
simulating the action of a wounded and terrified bird struggling to
escape in order to safeguard its young, is that one, very strong in all
ground-breeding species, of sitting close on the nest in the presence of
danger. Here, too, the instinct is of prime importance to the species,
since the bird by quitting the nest reveals its existence to the
prowling, nest-seeking enemy--dog, cat, fox, stoat, rat, in England;
and in the country where I first observed animals, the skunk, armadillo,
opossum, snake, wild cat, and animals of the weasel family. By leaving
its nest a minute or half a minute too soon the bird sacrifices the eggs
or young; by staying a moment too long it is in imminent danger of being
destroyed itself. How often the bird stays too long on the nest is seen
in the corn-crake, a species continually decreasing in this country
owing to the destruction caused by the mowing-machine. The parent birds
that escape may breed again in a safer place, but in many cases the bird
clings too long to its nest and is decapitated or fatally injured by the
cutters. Larks, too, often perish in the same way. To go back to the
ailing or wounded bird simulating action: this is perhaps most perfect
in the gallinaceous birds, all ground-breeders whose nests are most
diligently hunted for by all egg-eating creatures, beast or bird, and