www.resilience.org
Humans have pushed bird populations toward extinction. Peregrine recovery efforts offer valuable conservation lessons
In 1963, Joseph Hickey—a professor of wildlife management at the University of Wisconsin—read Derek Ratcliffe’s recently published paper on the peregrine falcon’s status in Britain. The report highlighted the bird’s desertion of nesting territories and suggested that pesticides might be responsible for the falcon’s precipitous decline. As he absorbed Ratcliffe’s alarming analysis, Hickey recalled a rumor he had heard the previous year that not a single peregrine chick had fledged in the Northeastern United States. Ratcliffe highlighted the bizarre egg breakages and disappearances that he and others had documented in peregrine nests since 1949 and speculated on the causes of this unprecedented ornithological phenomenon. One possible cause, he wrote, might be “defects of the egg.” “If, for some reason, Peregrine eggshells had recently become thinner,” he continued with visionary boldness, “an increase in breakage might be expected.” But he conceded that he had not measured the thicknesses of the broken eggshells, and given the normal thinning of shells during incubation, none of the eggs he’d examined seemed unusual. Reading these speculations, Hickey noted that Ratcliffe’s hypothesis could be objectively tested. “I am told poultry science people… routinely measure shell thickness,” he wrote on Ratcliffe’s manuscript, recommending that the British scientist...
