Injurious birds are few. Of course birds which are the enemies of other birds are enemies of mankind, but examples are scarce (some owls and hawks). Many birds of prey are classed thus by mistake. Sparrow-hawks, for instance, do not eat birds except in rare instances; they feed chiefly upon insects. A sparrow hawk often keeps watch over a field where grasshoppers are plentiful and destroys great numbers of them. When a bird is killed because it is supposed to be injurious, the crop should always be examined, and its contents will often surprise those who are sure it is a harmful bird. The writer once found two frogs, three grasshoppers, and five beetles that had been swallowed by a “chicken hawk” killed by an irate farmer, but no sign of birds having been used for food. Fowls should not be raised in open places, but among trees and bushes, where hawks cannot swoop. Birds which live exclusively upon fish are, of course, opposed to human interests. Pigeons are destructive to grain; eagles feed chiefly upon other birds. [Illustration: FIG. 313.—ROAD RUNNER, or chaparral bird (Tex. to Cal.). What order? (Key, p. 177.) ] If the birds eat the grapes, do not kill the birds, but plant more grapes. People with two or three fruit trees or a small garden are the only ones that lose a noticeable amount of food. We cut down the forests from which the birds obtain part of their food. We destroy insect pests at great cost of spraying, etc. The commission the birds charge for such work is very small indeed. (See pages 177–183.) [Illustration: FIG. 314.—WOOD DUCK, male (_Aix sponsa_). Nests in hollow trees throughout North America. Also called summer duck in South. Why? ] The =English sparrow= is one bird of which no good word may be said. Among birds, it holds the place held by rats among beasts. It is crafty, quarrelsome, thieving, and a nuisance. It was imported in 1852 to eat moths. The results show how ignorant we are of animal life, and how slow we should be to tamper with the arrangements of nature. In Southern cities it produces five or six broods each year with four to six young in each brood. (Notice what it feeds its young.) It fights, competes with and drives away our native useful birds. It also eats grain and preys upon gardens. They have multiplied more in Australia and in North America than in Europe, because they left behind them their native enemies and their new enemies (crows, jays, shrikes, etc.) have not yet developed, to a sufficient extent, the habit of preying upon them. Nature will, perhaps, after a long time, restore the equilibrium destroyed by presumptuous man. =Protection of Birds.=—1. Leave as many trees and bushes standing as possible. Plant trees, encourage bushes. 2. Do not keep a cat. A mouse trap is more useful than a cat. A tax should be imposed upon owners of cats. 3. Make a bird house and place it on a pole; remove bark from pole that cats may not climb it; or put a broad band of tin around the pole.