This section is from the book "The Balance Of Nature And Modern Conditions Of Cultivation", by George Abbey. Also available from Amazon: The Balance Of Nature And Modern Conditions Of Cultivation.
Feeding entirely upon insects-night-flying moths, beetles, gnats, etc. this bird is strictly protected. Sometimes, however, it is captured in glade-nets, stretched in narrow glades or ridings in woods from tree to tree, ostensibly for catching hawks, but harmless night-flying birds often fall victims in glade-nets to the "setters'" rapacity.
This bird has lofty ideas in nesting and flight, and scours the open spaces in towns and their environs in quest of insects incessantly from dawn to dusk, freeing the air of countless pests.
These birds render untold service to foresters, osier-growers and farmers by river and stream-sides. Anglers, however, complain of small bird protection resulting in a relative scarcity of mayflies, etc., so that both the fish and sport are embarrassed.
Delightful in song and harmless in habits, this bird is a general favourite and welcomed by every one, except the farmer, when its presence draws crowds of listeners to trample down his meadow grass and other crops. For capturing nightingales a trap, called the nightingale trap, a compromise between the bow-net and the spring trap, is used, also for taking most insectivorous birds, and may be bought at most bird-shops.
In devouring the pests of forest-trees, particularly leaf-rolling caterpillars, the chiff-chaff is pre-eminent; and for clearing woods, thickets, pleasure grounds and gardens of insect pests the willow warbler has no rival.
Ants and their "eggs," flies, moths, spiders, caterpillars, worms and beetles enter largely into the fare of this bird, and as it never touches fruit and builds its nest in orchards and about houses, no one has a bad word for it.
Nothing but good can be said about this, and also the Yellow Wagtail and White Wagtail, as they feed almost entirely upon insects, and are true friends of sheep-farmers in destroying the water snails that act as hosts to the liver-fluke.
There is no bird with a better character for working on behalf of the forester, farmer and gardener, as it exercises its good influence in wooded districts, clearing innumerable caterpillars in feeding its young and the surface pests away from streams that wagtails may not trouble about.
Mute and familiar, this bird works with a will on insects that have taken to flight by the time of its arrival in Britain, seizing sawflies, large moths, such as the yellow underwing, white butterflies, flies, beetles, aphides and other pests on wing. It visits and nests in town parks and gardens, and destroys pests that plague men and animals, or injure wild and cultivated crops. Flycatchers are said to eat cherries and raspberries, but this, as in some other cases of insectivorous birds, is for the living creatures found upon the fruit.
Although young birds, some say of game, may enter into the menu of the shrikes, essential service in destroying cockchafers, grasshoppers, dragon-flies and other insects is rendered to arboriculture, agriculture, horticulture and pisciculture. The prey of these birds is mostly taken on wing, after the manner of the flycatchers.
What the warblers, frequenting osier-beds and wooded margins of streams, effect in destroying insects, has its reflex in the siskins' feeding largely upon weed-seeds in those localities, though some aver that the birds are a means of scattering seed over the land, ignoring the fact of seeds digested being lifeless.
Feeding upon small seeds, such as wild sorrel, knapweed, plantain and other obnoxious weeds, this bird is useful, and would be more so if bird-catchers were not allowed to capture them on waste places where weeds flourish and "winged" seeds perfect.
The ants, "farming" aphides, have no greater enemy, and the pests infesting tree stems and limbs no more assiduous "rooters " out than the wrynecks.
For devouring hairy caterpillars, even "woolly bear," and particularly gooseberry caterpillars, combined with all the hairy gentry that feast and fatten on foliage in woods, coppices, hedgerows, fields, fruit plantations and gardens, this bird is unequalled. It also eats flies, beetles, grasshoppers, surface larvae, such as leather-jackets and wireworms, millipedes and molluscs, but its chief food is caterpillars. The young are mostly reared by the foster-parents on smooth caterpillars until they are able to obtain their own food.
This bird is to riversides in summer what the woodcock represents in winter, viz. the destruction of countless worms, molluses and insects, which are not beneficial to land crops, whatever may be claimed for them in behoof of fish.
This bird is useful by feeding upon worms, molluscs, Crustacea and insects in fen districts. In former times advantage was taken of the devotion of the males to the females by decoying them into nets or snares when " hilling," by previously setting nooses or nets in their battleground, into which they danced when fighting.