[74] Professor Treadwell, of Massachusetts, found that a half-grown American robin in confinement ate in one day sixty-eight earthworms, weighing together nearly once and a half as much as the bird himself, and another had previously starved upon a daily allowance of eight or ten worms, or about twenty per cent. of his own weight. The largest of these numbers appeared, so far as could be judged by watching parent birds of the same species, as they brought food to their young, to be much greater than that supplied to them when fed in the nest; for the old birds did not return with worms or insects oftener than once in ten minutes on an average. If we suppose the parents to hunt for food twelve hours in a day, and a nest to contain four young, we should have seventy-two worms, or eighteen each, as the daily supply of the brood. It is probable enough that some of the food collected by the parents may be more nutritious than the earthworms, and consequently that a smaller quantity sufficed for the young in the nest than when reared under artificial conditions.
The supply required by growing birds is not the measure of their wants after they have arrived at maturity, and it is not by any means certain that great muscular exertion always increases the demand for nourishment, either in the lower animals or in man. The members of the English Alpine Club are not distinguished for appetites which would make them unwelcome guests to Swiss landlords, and I think every man who has had the personal charge of field or railway hands, must have observed that laborers who spare their strength the least are not the most valiant trencher champions. During the period when imprisonment for debt was permitted in New England, persons confined in country jails had no specific allowance, and they were commonly fed without stint. I have often inquired concerning their diet, and been assured by the jailers that their prisoners, who were not provided with work or other means of exercise, consumed a considerably larger supply of food than common out-door laborers.
[75] I hope Michelet has good authority for this statement, but I am unable to confirm it.
[76] Apropos of the sparrow—a single pair of which, according to Michelet, p. 315, carries to the nest four thousand and three hundred caterpillars or coleoptera in a week—I take from the Record, an English religious newspaper, of December 15, 1862, the following article communicated to a country paper by a person who signs himself "A real friend to the farmer:"
"Crawley Sparrow Club.—The annual dinner took place at the George Inn on Wednesday last. The first prize was awarded to Mr. I. Redford, Worth, having destroyed within the last year 1,467. Mr. Heayman took the second with 1,448 destroyed. Mr. Stone, third, with 982 affixed. Total destroyed, 11,944. Old birds, 8,663; young ditto, 722; eggs, 2,556."
This trio of valiant fowlers, and their less fortunate—or rather less unfortunate, but not therefore less guilty—associates, have rescued by their prowess, it may be, a score of pecks of grain from being devoured by the voracious sparrow, but every one of the twelve thousand hatched and unhatched birds, thus sacrificed to puerile vanity and ignorant prejudice, would have saved his bushel of wheat by preying upon insects that destroy the grain. Mr. Redford, Mr. Heayman, and Mr. Stone ought to contribute the value of the bread they have wasted to the fund for the benefit of the Lancashire weavers; and it is to be hoped that the next Byron will satirize the sparrowcide as severely as the first did the prince of anglers, Walton, in the well known lines:
"The quaint, old, cruel coxcomb in his gullet
Should have a hook, and a small trout to pull it."
[77] Salvagnoli, Memorie sulle Maremme Toscane, p. 143. The country about Naples is filled with slender towers fifteen or twenty feet high, which are a standing puzzle to strangers. They are the stations of the fowlers who watch from them the flocks of small birds and drive them down in to the nets by throwing stones over them. See Appendix, [No. 14].
Tschudi has collected in his little work, Ueber die Landwirthschaftliche Bedeutung der Vögel, many interesting facts respecting the utility of birds, and the wanton destruction of them in Italy and elsewhere. Not only the owl, but many other birds more familiarly known as predacious in their habits, are useful by destroying great numbers of mice and moles. The importance of this last service becomes strikingly apparent when it is known that the burrows of the mole are among the most frequent causes of rupture in the dikes of the Po, and, consequently, of inundations which lay many square miles under water.—Annales des Ponts et Chaussées, 1847, 1re sémestre, p. 150. See also Vogt, Nützliche u. schädliche Thiere.
[78] Wild birds are very tenacious in their habits. The extension of particular branches of agriculture introduces new birds; but unless in the case of such changes in physical conditions, particular species seem indissolubly attached to particular localities. The migrating tribes follow almost undeviatingly the same precise line of flight in their annual journeys, and establish themselves in the same breeding places from year to year. The stork is a strong-winged bird and roves far for food, but very rarely establishes new colonies. He is common in Holland, but unknown in England. Not above five or six pairs of storks commonly breed in the suburbs of Constantinople along the European shore of the narrow Bosphorus, while—much to the satisfaction of the Moslems, who are justly proud of the marked partiality of so orthodox a bird—dozens of chimneys of the true believers on the Asiatic side are crowned with his nests. See App. [No. 15].