It has been estimated that the average domestic cat kills an average of one song bird a day during the season when the birds are with us.  In certain sections a cat has been known to destroy six nests of orioles, thrushes and bobolinks in a single day.  The worst offenders are cats that live around barns and old houses in a half wild condition.  Many people who say they “haven’t the heart to kill a cat” will take it away from home and drop it along the road.  A thoughtless act like this may mean the death of a hundred birds in that neighbourhood.  It takes less heart to kill the cat than to kill the birds.  So much for the cat.

[Illustration:  A bird house]

Birds make splendid pets, but in keeping them in captivity, we must be sure that we are not violating the game laws of the state we live in.  Nearly everywhere it is unlawful to keep in cages any native song birds or those that destroy harmful insects—­the so-called “insectivorous birds.”  This includes thrushes, wrens, robins, bluebirds, orioles or, in fact, practically all birds but crows, blackbirds and kingfishers.  It does not cover canaries, parrots, or any birds that are not native.  It is an excellent law and every boy or girl should act as a special policeman to see that his friends and companions do not molest either birds or their nests.  It is cruel to cage a wild bird anyway for a cage is nothing but a prison.  There is no law against taming the birds or making friends of them and after all this is the most satisfactory way.

If we build houses for the birds to nest in, provide feed for them and in other ways do what we can to attract them, they will soon learn that we are their friends.  We must study their habits and always avoid frightening them.  Next to a cat, the worst enemies of our song birds are the English sparrows.  A sparrow is always fair game for the boy with a slingshot or rifle.  In many places these sparrows have driven practically all the other birds out of the neighbourhood, have robbed their nests and in other ways have shown themselves to be a public nuisance.  Until 1869 there were no sparrows in this country and now they are more numerous than any other variety of birds, and sooner or later, the Government will have to take steps to exterminate them or we shall have no song birds at all.

The usual size of a bird house is six inches square and about eight inches high.  It should always be made of old weather-beaten boards in order not to frighten away its prospective tenants by looking like a trap of some kind.  The chances are that the sparrows will be the first birds to claim a house unless we keep a close watch and drive them away.

One way to keep them out is to make the entrance doorway too small for them to enter.  A hole an inch in diameter will admit a wren or chickadee and bar out a sparrow, but it will also keep out most of the other birds.  The usual doorway should be two inches in diameter.  It is surprising how soon after we build our bird house we find a tiny pair making their plans to occupy it and to take up housekeeping.  Sometimes this will happen the same day the bird house is set up.  Always provide some nesting material near at hand; linen or cotton thread, ravellings, tow, hair and excelsior are all good.  Of course we must not attempt to build the nest.  No one is skillful enough for that.