Sunday, March 1, 2009

up in the sky!

Where would you go if you wanted to see one of the fastest predators on earth?
Would you believe me if I told you that right now you have a good chance of finding one at Main and Beale in downtown San Francisco?


No, cheetahs aren't hanging in the Financial District, but a couple of Perigrine falcons (Falco peregrinus) are. How do you know if you're looking at a peregrine? They are crow-sized falcon, with a blue-gray back, barred white underparts, and a black head and "moustache". These birds can be found all over the world, hence the name, which means "wandering falcon" (a fancy word for wandering around on foot is "peregrination").

The Peregrine Falcon became an endangered species due to the use of pesticides, especially DDT. Since the ban on DDT in the 1970s, the many populations have recovered, supported protection of nesting places and releases to the wild. Interestingly, lots peregrines have settled in cities, with tall buildings that stand in for cliff faces and a plentiful supply of food (especially pigeons). They search for prey either from a high perch or from the air. Once prey is spotted, it begins its stoop, a dive in which they can reach speeds of 200 mph. Peregrines strike their prey with a clenched foot, which stuns or kills it, then turn to catch it mid-air. I saw a peregrine catch a pigeon on Mission and 3rd-it's a truly impressive display.

The fine folks at the Santa Cruz Predatory Bird Group have been instrumental in the recovery of peregrines in California. As part of their education and outreach they have installed cameras in San Francisco and San Jose to allow the public to peer into the lives of these amazing birds. There has been much drama with the San Francisco birds with the much loved Gracie and George abandoning downtown for the Bay Bridge and then vanishing altogether from the city. This year there are two new birds on the nest cam.-now is a great time to start watching. Peregrines mate for life and go through some really charming courting in the lead up to mating. Sadly (or luckily for my productivity) I can't stream video at work, but if you can, you should check it out.

If you want to see some truly remarkable images of these (and other) birds, check out the website of Glenn Nevill. Or, if you want to try to catch one in person, try some of the spots on this map.

Happy perigrinations!

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