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City Peregrines Pursue the Country Life

On a breezy hilltop near San Gregorio, California, Scott Sokol helps me band the last three peregrine falcons that we will release this summer. At about 400 feet above sea level, it is a quiet place where the sound of the distant surf is a constant presence. The 35-day-old falcons we prepare for release are the progeny of peregrines that chose the Vincent Thomas Bridge as a nest site—a decision that endangered the young’s survival.

The bridge is a tall arching span that connects the cities of San Pedro and Long Beach, and overlooks one of the world's busiest harbors. It is a place where rock doves, better known as city pigeons, have flourished on a diet of spilled grain and the leavings of catering trucks. The pigeons in turn provide an ample diet for falcons that inhabit the gulf of air above the industrial complex, using tall man-made structures for perches and nesting.

For tens of thousands of years, peregrine falcons have chosen the high places of the world to nest, perch, and roost. Bridges across waterways provide perfect hunting perches for falcons. There they enjoy an advantage over prey species crossing the water with no place to avoid the pursuit of peregrine falcons. In time, a territory is established and the peregrines search for a ledge that is suitable for nesting, and lay a clutch of eggs.

Everything goes well until the young falcons attempt to fledge. The initial, uncertain flights of young peregrines from bridges often end in disaster when the birds land on the bridge's roadbed or in the water below the bridge. Landing seems to be one of the most challenging aspects of flight for a young falcon and they usually flutter to a nearby ledge or slope below the nesting cliff. Of course that is impossible if the nest site is a bridge, and so the Predatory Bird Research Group has an agreement with Caltrans to rescue young peregrines from certain California bridges and release them in areas where the population is still recovering.

Our San Gregorio hack site is an ideal place for peregrine releases. The weather is consistently cool and wisps of fog often roll across the hilltop. There is open, rolling country for several miles in all directions, affording newly fledged falcons a view of the hack box from almost any perch in the area. And the native plants and wildlife are a constant source of interest and enjoyment for hack site attendants as they record observations of peregrines learning to dominate the sky.

Scott Sokol has been on the job at the San Gregorio hack site since mid-May. Other attendants have come and gone but Scott has found a home in this lonely outpost. His perseverance has been rewarded. Now regarded as just another aspect of the hilltop environment, he sees things most people never will. Shortly after I arrived one day he said, "I was walking along the trail between camp and the blind when a bobcat pounced just ten feet away. I froze and it froze and we just stared at one another. As I watched it I could see its prey swimming around in its mouth so I walked on allowing it to finish its meal." Scott says that he sees the bobcat almost every day, often hunting in an adjacent agricultural field as Scott sits in the blind. He has seen one of the released peregrines catch a blackbird over a nearby pond and red-tailed hawks pluck gophers and field mice from the hillside. And Scott was able to watch the nesting cycle of a pair of white-crowned sparrows that nested just twenty feet from the blind.

- Glenn R. Stewart