In the early 1960s, the Nature Conservancy formed a section at the Monks Wood Experimental Station (Huntingdon, England) to investigate the effects of pesticides on wildlife. This book gives the residue levels found in bird tissues and eggs during the period 1963-1977, and discusses the findings. The main contaminants investigated were DDE (from DDT), HEOD (from dieldrin and aldrin), PCBs and mercury. Illustrated. 74 pp.