The reason the birds attack is that global warming has caused them to be mutant, toxic and flammable.
On Saturday April 2 at 2pm, Green Apple will host James Nguyen, the "visionary creator" (his words, not ours) of what might be one of the great B-movies of all time: Birdemic: Shock and Terror. Produced for less than $10,000 and filmed in the Bay Area (and even partially on our own Clement Street), Birdemic is "a meditation on Hitchcock's classic and the environmental chaos caused by the industrial Age."
The film was recently written up in USA Today, which said "While Birdemic will probably never be honored at the Oscars — unless they add a Best Use of Exploding CGI Vultures category — Nguyen's enthusiasm for his so-bad-it's-good film and his do-it-yourself attitude were infectious to everybody around the low-budget production."
Nguyen has written a short memoir on his making of the movie, which he will be discussing on April 2. This might be one to mark on your calendar.