Scientists jumped to the rescue with some distinctly shaky evidence to the effect that insects would eat us up if birds failed to control them.

but we have at least drawn nearer the point of admitting that birds should continue as a matter of intrinsic right, regardless of the presence or absence of economic advantage to us. Time was when biologists some what overworked the evidence that these creatures preserve the health of game by killing the physically weak, or that they prey only on “worthless” species.

In Europe, where forestry is ecologically more advanced, the noncommercial tree species are recognized as members of native forest community, to be preserved as such, within reason.

It tends to ignore, and thus eventually to eliminate, many elements in the land community that lack commercial value, but that are essential to its healthy functioning.