Talk:Derek A. Ratcliffe

Peregrine studies
The first study, "Decrease in Eggshell Weight in Certain Birds of Prey," by British Nature Conservancy researcher D.A. Ratcliffe, was published in Nature on July 8, 1967. Ratcliffe claimed that the incidence of broken eggs in nests of peregrine falcons, sparrowhawks, and golden eagles had increased considerably since 1950. He compared eggshells collected before 1946 with eggshells collected afterward, and found that post-1946 peregrine falcon eggshells weighed 19 percent less; sparrowhawks' weighed 24 percent less; and golden eagles' 8 percent less. Ratcliffe dismissed lack of food and radioactive contamination as explanations for the thinning, but noted "some physiological change evidently followed a widespread and pervasive environmental change around 1945-1947... For the species examined, frequency of egg-breakage, scale of decrease in eggshell weight, subsequent status of breeding population, and exposure to persistent organic pesticides are correlated. The possibility that these phenomena are links in a causal chain is being investigated," he concluded. 


 * Perhaps the above could be turned into an article. It's relevant to the "egg shell thinning in raptors" claims of Silent Spring. See also DDT ban and Rachel Carson.