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.
To agriculturists this bird is of great service in keeping down field and grass voles, mice and young rats, beetles and other insects. Its services, however, are mostly confined to tracts that are relatively left to take care of themselves, such as heaths, moors, bracken-places, furzy downs, hill pastures, and marshy meadows in the north of England and in Scotland, though not infrequently found in tracts of highly cultivated land, from John o' Groats to Land's End, there, of course, being some intermingling of wild with cultured stretches of country. This means the broad distinction between Nature and Culture. In the former the creation takes its course with little interference by man, but certain creatures increase to the advantage of the sportsman, and this by keeping down vermin-carnivorous beasts and birds of prey. These live upon herbivorous or vegetation-feeding animals and birds, which increase proportionately with the decrease of the carnivora or balancing forces of nature, and there follows a plethora of deer, hares and rabbits, grouse, partridge and other winged game, with a vast increase of vegetable-feeding, fruit and grain devouring birds. This is really success for the sportsmen, and in measure profit to the nation, by the destruction of vermin.
But even this cannot be pursued without incurring famine, for the ruminants and rodents so increase as to eat and foul themselves out of existence. This, of course, does not occur in Britain, simply because the numbers are regulated and the ground changed to ensure health and due proportion of subjects to area. This is culture-game preservation and up-keep, with no advantage to general agriculturists, though winged game destroys many insect and other pests that feed upon vegetation. The rodents not classed as game tell against ground game as directly and against winged game as indirectly, as in the crops of the forester, farmer and gardener, a like remark applying to vegetarian birds, with a distinction - the game-preserver has no crop damageable by them, and fosters their increase by the re strictions in respect of game preservation, and more especially by the decimation of weasels, hawks (particularly the kestrel) and owl (particularly the barn and short-eared).
But there is another side to this question, viz., what restrictive measures does the forester, farmer and gardener take to protect their crops from the ravages of wild vegetable-feeding animals and birds, which in their several forms are as much vermin in respect of forest, field and garden crops, as are carnivorous animals and preying birds to game culture? The most that can be expected of game preservers is discrimination in the destruction of what is known to them as vermin. But it must be remembered that exclusive reliance cannot be placed on natural checks, and it is useless to decry the vigorous preservation of game as accountable for plagues of mice and voles, for history refutes such dictum, inasmuch as long before game preservation had interfered with the natural enemies of the rodents, Great Britain was subject to periodical swarms of mice and voles. The only precaution possible is watchfulness, and combined action on the part of foresters, farmers and gardeners, so that as soon as the first symptoms of undue increase of vermin is detected, prompt steps be taken to avert the recurrence of grievous damage.
This, the destruction of vermin, is imperative for the success of all cultures, no vigilance being relaxed, no trust placed on empyrics, but adoptThe good old plan, That he should take who has the power, And he should keep who can.