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PROTECTION AGAINST DESTRUCTIVE BIRDS.
Though on the whole usually much slighter than the injuries caused by insect enemies, or even in many cases by deer and ground-game, the damage done to woodlands and nurseries by birds is occasionally by no means inconsiderable. But at the same time many species of carnivorous birds are of decided utility by feeding on small ground-vermin and insects; others are to a certain extent beneficial with regard to one portion of their food, though often also injurious as regards the rest of their feeding; whilst others again must be reckoned decidedly injurious.
A. With regard to Ground-Vermin.-Among the birds that may be classed as undoubtedly useful in keeping down the number of mice and voles are the Buzzards, and more particularly the Common Buzzard (Buteo vulgaris); the Kestrel, Wind-hover, or Stannel Hawk (Tinnunculus alaularius); the Owls, especially the White or Barn Owl (Strix flammea), the Long-eared Owl (Otus vulgaris), the Short-eared Owl (0. brachyotus), the Tawny Owl (Syrnium aluco), and the Little Owl (Noctua), which only visits us occasionally; the Rook (Corvus frugilegus), during the autumn in particular, the Common or Carrion Crow (C. corone), the Hooded Crow (C. cornix), the Jackdaw (Monedula turrium), and some of the Hawks (Strigiceps).
These birds all do exceedingly useful work in maintaining the due balance of nature. Even though the Rooks and Crows and Jackdaws often scratch up seed from the nursery-beds during the late autumn and the winter, yet the amount of good they do in helping to keep down any inordinate increase in the number of prolific voles and mice, most decidedly entitles them to have their offences condoned. In killing Kestrels by mistake for Sparrow-hawks the farmer destroys one of his best friends, and thereby actually protects voles.
In addition to the above, many other birds of prey likewise aid in keeping down ground-vermin ; but as they also possess very distinct hankerings after young game-birds and insectivorous singing-birds, the damage they do on these accounts places them beyond the pale of the forester's protection.
For details about the Kestrel, the Short-eared Owl, and the Barn Owl, see Board of Agriculture Leaflets Nos. 40, 42, and 51.
B. With regard to Injurious Insects. When we come to consider the classes of insectivorous birds most deserving protection, a much larger number presents fair claims for preservation by every means in our power. It includes, again, many of those already entitled to our protection for their aid in restricting the abnormal multiplication of mice and voles, so that such have a twofold claim to our favourable attention.
I. Decidedly useful Birds.—The birds of greatest utility in checking the numerical increase of injurious insects are the Cuckoo (Cuculus canorus), which feeds principally on hairy caterpillars that are avoided by most other birds; the Starling (Sturnus vulgaris), the Tits (Paride), the Creepers (Certhide), the Swallows, Martins, and Swifts (Hirundines), the Warblers (Sylviæ), the Nightingales (Lusciniæ), the Wrens (Troglodytes), the Accentor or Common Hedge-sparrow (Accentor modularis), our summer visitor the Redstart (Ruticilla phoenicura), the Robin or Redbreast (Erythacus), the Whitethroat (Curruca cinerea), the Stonechat (Saxicola), Flycatchers (Musicapince), Wagtails (Motacillince), the Titlark or Meadow-pipit (Anthus pratensis), and the Nut-hatch (Sitta europea). All the Owls, except the Eagle Owl or Greateared Owl (Bubo maximus), a rare bird, do good by feeding on grubs, though here again the Long-eared Owl (Otus vulgaris) and the Tawny Owl (Syrnium aluco) render best service in this respect, while the Fern-owl, Goat-sucker, or Nightjar (Caprimulgus europeus) feeds on night insects (cockchafers and moths). Of the sea-birds which come inland for breeding purposes, gulls generally, and the Brown- or Black-headed Gull (Larus ridibundus) in particular, give most aid in preventing any undue increase among noxious insects.
All of these birds deserve protection. Though many of them levy toll on orchards, yet attempts to diminish their numbers must result in favouring the increase of insect pests, and thereby lead to very much worse results in the longrun, because the latter are endowed with enormously prolific power.
Many have declared the Cuckoo to be perhaps more of a nuisance than a blessing; but during a plague of the Processionary Moth or Oak-spinner (Cnethocampa processionea) in Germany, Prof. Altum found no less than ninety-seven caterpillars, of about one-third of their full growth, in the stomach and intestines of a Cuckoo.1
The Starling is, along with the useful Hedge- warbler or Hedge-sparrow (Accentor modularis), one of the victims of the Cuckoo's attentions during the breeding-time. In order to protect its eggs and its young, however, against Cuckoos, wild cats, and other enemies, very useful aid is given to its protection by hanging up wooden nesting-boxes in the branches of trees (p. 64). It is marvellous how quickly the birds respond to this attention ; and as the entrance-holes are too small to admit the Cuckoo, and the nesting-place is deep enough below that to be beyond the reach of a cat's paw, an effective measure for their increase can be adopted at slight cost, as the boxes cost little, and last for many years. Two other birds, close relatives of the Cuckoo, but of rather rare occurrence in England, the Roller (Coracias garrula) and the Hoopoe (Upupa epops), also deserve protection whenever they come as fleeting guests, for they too are exceedingly useful in feeding on caterpillars.
The whole family of the Tits or Titmice (Paride) are worthy of all the protec
1 During the plague of Black Arches (Liparis monacha) in Bavaria in 1889-91, the Starlings flocked in thousands to the forests attacked in order to feed on the caterpillars, whilst the complaints of the market-gardeners were loud at these useful birds having for the time being forsaken their gardens, even although their guardianship has to be paid for by a tithe of cherries.
tion which we can bestow on them, as they wage a most successful warfare against our insect enemies. The Great Titmouse (P. major), the Blue Tit or “ Billy-biter” (P. coruleus), the Long-tailed Tit (P. caudatus), the Black Tit (P. ater), and the Crested Titmouse (P. cristatus) are more particularly the species which render best service in placing limits to the rapid numerical increase of insects. In young plantations and in nurseries the Wrens are continually inspecting the youngest shoots of conifers, and thus free them from ova and grubs of many sorts ; whilst the Chiff-chaff (Sylvia rufa), a more common visitor in the south of England than in the colder and less hospitable north, immediately on its arrival in spring pays special attention to the leaf-rolling caterpillars that infest the young foliage and tender early buds of trees, as well as to the various forms of Aphidæ which the nurseryman and the gardener include within the comprehensive and elastic term “blight.” Belonging to the Passeres or Sparrow tribe, mention may also be made of an occasional summer visitor, infrequent even in England, and rare indeed in Scotland, the Golden Oriole (Oriolus galbula), which feeds for the most part on insects, although the temptation offered by the fruit in orchards is apt to tempt it away from the woods, particularly when the luscious cherries are ripening.
Many other birds are of partial use in devouring insects, whilst they undeniably commit a certain amount of damage to crops of various kinds or to young game-birds : others, again, do on the whole more harm than good. These may therefore be roughly divided into (II.) such as are more useful than injurious, and (III.) those that are more injurious than useful, and may be considered before the class of birds (IV.) that are undoubtedly destructive.
For details, see Board of Agriculture Leaflets Nos. 43 (Titmice), 45 (Starling), 50 (Water Wagtails), 54 (Plycatchers), and 55 (Swallows and Martins).
II. Species that are on the whole more Useful than Injurious.—In this class several sections of the Passeres or Sparrows must be included, even although they mainly subsist on corn and grain as their staple food, and only attack insects in an irregular and spasmodic manner. Local circumstances to a certain extent determine whether or not they are entitled to be classed as useful on the whole ; and where careful, unprejudiced observation seems to point to their doing more harm than good, then there can be no justification for affording them unlimited protection, as in the case of all the kinds of birds that have been included among the very useful species already enumerated. To this class of limited utility in respect to the suppression of insect enemies belong certain of the Finches (Fringillidre), Larks (Alaudide), Woodpeckers (Picida), Thrushes and Blackbirds (Turdidee), the Jackdaws, Rooks, and Crows (Corvido), the Common Buzzard (Buteo vulgaris), the Kestrel or Stannel Hawk (Tinnunculus alaudarius), the Peewit, Lapwing or Green Plover (Vanellus cristatus), and the Snipe (Gallinago). Of the birds of passage, the Honey Buzzard (Pernis apivorus) devours large numbers of the larvæ of wasps and other injurious insects, as well as those of bees unfortunately, while the Woodcock (Scolopax), which passes the winter with us, issues forth at night from the thickets in which it spends the day, and feeds on the worms and insects to be found on low-lying wet lands.
For details about the Plover, see Board of Agriculture Leaflet No. 44.
The Finches form a very large family of small and interesting birds, including many of our sweetest songsters. From the conical construction of their beaks, it is evident that they have been gifted by nature with special facility for feeding on
hard seeds like peas and grain. Of those that may be classed as useful rather than destructive, the Bullfinch (Pyrrhula rubricilla), the Goldfinch or Thistlefinch (F. carduelis), the Lintie or Common Linnet (F. cannabina), and the Greenfinch or Green Linnet (F. chloris) are all well-known frequenters of our fields, gardens, nurseries, and orchards, where they feed partly on insects and partly on seeds ; whilst the Siskin (F. spinus), an autumn visitor merely, is a comparatively rare bird in England, though it is less infrequent in Scotland, where it occasionally stays to breed. The other Finches are generally more destructive than useful.
The two principal species of our British Larks are the Skylark (Alauda arvensis) and the rarer and smaller Woodlark (A. arborea), the latter of which derives its name from the fact of its often singing whilst perched on trees, a power that is denied to the former. Both species, however, nest on the ground, and both are on the whole deserving of protection.
The Woodpeckers form a class about which a good deal of misinformation is current. It was formerly supposed that they hollowed out holes in the stems of trees only when these were infested by noxious insects. But closer observations have shown that in many cases they peck holes in perfectly sound stems, and that the insects they hunt after are frequently Cerambycidæ, of little sylvicultural consequence compared with the injurious Scolytida they often neglect under the bark.
There can be no doubt that Woodpeckers often consume during the winter months a fairly large quantity of the seed of trees (especially of Spruce and Pine, which they extract from the cones, and of shell-fruits), and can individually do a deal of damage at times by pecking holes in ornamental trees occupying isolated positions (especially after they have been feeding in coniferous woods and have their beaks rendered uncomfortable by resin), as well as by picking the rind off sturdy transplants and young trees of smooth-barked species, and by girdling young trees of all sorts during May and June for some purpose not yet accurately determinable. But the total damage is confined within narrow limits from the fact that all the species of Woodpeckers are to be found at work singly in the woods, and not in flocks. Thus, when injuries on sound avenue or ornamental trees begin to occasion uneasiness, the shooting-off of an individual bird usually puts an end to the mischief. And on the other hand, it is equally certain that during the spring and summer months they feed to a very large extent, mainly in fact, on insects which they either pick out from the ground (as in the case of cockchafer grubs, mole-crickets, earthworms), or from the branches and bark of trees (as in the case of many caterpillars and chrysalides), or from the cambium and the interior of the stem (as in the case of many bark-weevils, beetles, wood-wasps, &c.), for the extraction of which their long, pointed tongue is specially adapted by being furnished with hook-like hairs or barbs pointing backwards. Nor is the least part of their utility attributable to the fact that the chambers they thus hollow out with their strong beaks, when hunting after grubs and beetles in the interior of the stems of large trees, are utilised as nesting-holes or breeding-places by Woodpeckers themselves, as well as by a considerable number of other very useful insectivorous birds, like Starlings and Tits, which would in more open nests be exposed to the undesirable attentions of cuckoos, wild cats, and other enemies.
The most common of this family of birds in Britain is the Green Woodpecker, Woodspite, or Yaffle (Picus viridis). The Wryneck (Yunx torquilla), a small species, is a not infrequent summer visitor in the warmer southern counties of England ; while the Great Spotted Woodpecker or Woodpie (Dendrocopus major), the largest species, and at the same time that which does most damage, is only occasionally to be found in England. It usually takes up its haunts in the stillness of large woods.
Among the Turdide, three species are common in Britain at all times of the year, the largest being the Missel-thrush or Stormcock (Turdus viscivorus), which is somewhat bigger than either the Throstle or Mavis (T. musicus), or the Black
bird (T. merula). These are all three sweet songsters, and the first named is one of the few birds whose notes ring through the woodlands late in winter, when even the Throstle has become silent, and many of the other singing-birds have long since flown to warmer lands. To make up for their temporary silence, however, the Mavis and the Blackbird not only do a considerable amount of good by clearing young plantations, nurseries, and gardens of earthworms, snails, cockchafer grubs, and other insects, but also assist in the distribution and reproduction of many kinds of useful trees and shrubs on whose berries they feed during the winter months. That the first-named thus likewise assists in the spread of mistletoe is a misfortune, though certainly not one of any serious extent, as in orchards near large towns it may even be desirable for the old-fashioned Christmas rites. Were it not that all the Thrushes have such a weakness for every kind of garden-fruit, but more especially for cherries and raspberries, they would be well worthy of a place among the birds of unquestionable utility. The Ring-ouzel (T. torquatus), a summer visitor to the British Isles, is also useful. The Redwing (T. iliacus) and the Fieldfare (T. pilaris), both winter visitors, feed on slugs and insects as well as on hedge-fruits and the seeds of forest-trees; but they are not of such utility as the other Thrushes, for they are absent when insects are most numerous in spring and summer. Thrushes are also specially useful in killing snails (see p. 52).
Of the Crows, the Jackdaw, the Common or Carrion Crow, the Hooded Crow, the Rook, and the Chough (Fregilus graculus) all make up for their assaults on gardens and nurseries by waging war against cockchafer grubs, daddy-long-legs, wireworms, and similar insects, as well as grasshoppers and beetles, that are injurious both in the corn-fields and the market-gardens and nurseries. They seem fondest of a very mixed diet, embracing grubs, potatoes, corn, orchard fruits, fullgrown insects, and even an occasional chicken or tender duckling in the case of Rooks and Crows.
III. Species that are on the whole rather more Injurious than Useful.Besides certain Finches (which will be presently referred to), the Common or House Sparrow (Passer domesticus) does rather more harm than good in fields, gardens, and nurseries, owing to the fact of its feeding so often in large flocks, and not singly or in small flights merely.
The Shrikes or Butcher-birds (Lanine) live upon insects, frogs, mice, and small birds, many of these latter being species of considerable utility. The Great Grey Shrike (Lanius excubitor) is a much less frequent bird in England than the small red-backed species (L. collurio), which is the more useful of the two,—or rather, which does less harm than the former as regards killing insectivorous birds, as well as voles, &c.
To this category belong also the Magpie (Pica caudata), the now rare Raven (Corvus corax), and the equally rare Eagle Owl or Great-eared Owl (Bubo maximus), and nearly all the birds of prey included among Eagles, Falcons, and Hawks (Falconidæ). Of the latter, the Sparrow-hawk (Nisus .communis) is common in Britain, while the larger Goshawk (Astur palum. barius), a more characteristic dweller in the woods, and one whose protection would be entirely at variance with game-preserving, is comparatively rare. The Merlin (Hypotriorchis æsalon), indeed, the vicious dwarf among the falcons, feeds to a far greater extent on thrushes, larks, starlings, tits, wagtails, and the like than on mice and voles, and is therefore indirectly a dangerous enemy of woodlands and gardens by destroying various more useful species.
For details, see Board of Agriculture Leaflet No. 84 (The House-Sparrow).