Excerpt from University of California Publications in Zoology, 1912, Vol. 11 It is impossible, however, to determine accurately the full value of birds, for we cannot find out what the result would be upon the insect population, if all the birds were suddenly de stroyed. Yet a knowledge of their food leads us to conjecture that the destruction of so important an enemv of insects as the birds would result in a great increase in these enemies of vegeta tion and thus cause a serious disturbance in the balance of nature. The fact that birds destroy large numbers of injurious insects shows them to be important agents in contributing to the safety not only of crops, but also of all vegetation. A realization of the usefulness of birds promotes needed interest in and proteo tion for them. It is hoped that, as a result of this investigation and others in progress, the insectivorous habits of many of the common birds, and their consequent value, may be more generally known and appreciated by those who most profit by their activities; and also that this study of the relation of birds to a particular out break may add something of permanent value to the too meager knowledge of the part played by birds in maintaining the desired balance in nature. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.