by Andrea Williams
This post is the eighth in a year-long series celebrating the 40th anniversary of the Endangered Species Act. Read the previous post here.
Fastest animal alive, and thanks to the Endangered Species Act it’s still around. I’m talking, of course, about the American peregrine falcon (Falco peregrinus anatum) and its mind-boggling 200 mph killing dives. In the 1950s and 1960s, peregrine populations themselves were in a dive—from organophosphate (mainly DDT) pesticide use after World War II and also egg collection for falconry. By 1973, when the Endangered Species Act was passed, there were only a few hundred birds in the United States; peregrines were gone from the East Coast and down to fewer than five breeding pairs in California. The ban on DDT in the early 1970s, combined with a strong captive breeding and release program, has helped the U.S. population climb to over 3,000 birds and the American peregrine falcon was de-listed in 1999.
Sometimes my mind tries to make riddles out of how humans have changed the landscape, and how other animals have changed along with that. So instead of asking “How is a raven like a writing desk?”* I ask “How is a skyscraper like a cliff face?” And peregrines have answered the latter question with “I can lay an egg on it.”
During their rebound in the 1980s, peregrine falcons not only returned to their historic breeding sites in rocky spots such as Pinnacles National Monument and steadily increased at Point Reyes National Seashore, but started showing up in cities—nesting on the Golden Gate Bridge and Bay Bridge, as well as on tall buildings and smokestacks nationwide. But it can be dangerous raising young in an urban environment. While there are fewer predators (great horned owls and golden eagles, e.g.) and lots of pigeons, falling out of a nest that’s on a building or a bridge is much more deadly than one on a cliff, and first flights in a city can involve cars and buildings. Reintroduction (augmenting the existing population) stopped in California in 1992 but wild hatchling relocation continued until this year by groups such as the Santa Cruz Predatory Bird Research Group (SCPBRG) for those reasons. Nest productivity for both urban and wildland pairs appears similar in our area.
Generally, if I want to see a peregrine falcon I head to the coast. That’s where I saw my first one in the mid-90s, slicing through the air over the bluffs, and that’s where I most reliably see them today. But starting in February, you can see them anywhere you have an internet connection: numerous nest-cams exist, and the SCPBRG maintains a camera on a nest site at the PG&E building in San Francisco.
*The higher the fewer. Also, inky quills.