SAN FRANCISCO (CBS SF) — After decades of work, wildlife biologists have been so successful in bringing back the peregrine falcon that the powerful raptors now threaten Southern California’s endangered shorebird breeding sites.

As a result, the U.S. Fish and Wildlife Service says it will no longer permit peregrine chick rescues from Bay Area bridges, a move that they concede will likely lead to about a dozen fluffy chicks tumbling into the water below and drowning next spring.

FWS scientist Marie Strassburger says it’s time for nature to take its course.

But a biologist who helped bring the species back says it’s indefensible to ban him from rescuing a handful of chicks.

Peregrines nest high on cliffs, trees, buildings and bridges and hunt by diving at speeds topping 200 mph.

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