Collins, 2013. Binding: Paperback. Condition: New. Pages: 596 The New Naturalist Library: A Survey of British Natural History. Earlier naturalists formed the impression that bird numbers remained more or less stable through time. In the years since these words were written, however, changes have occurred in the landscapes of the.....

Academic Press, 1998. Illustrated By: Zimmerman, Dale A. Binding: Paperback. Condition: New. Pages: 597 The various factors that influence the population levels of wild birds, including the role of territorial behaviors, food supplies, predation, disease, competition, habitat destruction and more. Extensive bibliography.