San Francisco's Peregrine Falcons

It is not an uncommon sight in San Francisco’s Financial District to see pigeons disappear at lighting speed, attacked from on high by the city’s resident Peregrine Falcons.

These beautiful black and grey birds are one of the fastest animals in the world, reaching speeds up to 200 mph in a dive. Celebrated by falconers for hundreds of years, they were once abundant all over the world, but were pushed to the brink of extinction within the last fifty years.

Widespread use of DDT decimated the population by the 1970s, with just two known breeding pairs in California. In 1987, the first nest box was installed at the PG&E building in San Francisco, and Peregrines have been using the nest on and off since 2003.

Their preference to build their nests on scrapes or rocky ledges has led to problems with the birds trying to nest on bridges or on unwelcoming buildings, but that is what makes the nesting box at the top of the PG&E building an ideal nursery.

Bans on the use of DDT, combined with breeding programs have led to a resurgence of the population, and Peregrines were removed from the National Endangered Species List in 1999. As of 2010, California’s known population is estimated at about 800 individuals.

Peregrines now find homes in urban landscapes all over the world, including nests at Derby Cathedral in the UK, Brussels Cathedral in Belgium, and successful breeding programs in Canada, Virginia, and New York State.

The city’s current resident mating pair are known as Dapper Dan and Diamond Lil. In the early spring you can watch the aerial acrobatics of their mating ballet above the rooftops of the Financial District.