By now everyone has read about the news of "birds falling from the sky" out of Arkansas and Louisiana. So far, necropsies performed on representative samples of the birds have all indicated that the creatures died of internal bleeding and blunt-force trauma, with no indications of any sort of poisoning or lightening strikes involved.
While both the political and Biblical/Apocalyptic conspiracy theorists are tripping all over each other trying to paint the unfortunate event with their own special brand of crazy, those of us who keep exotic birds in our homes recognize this for what it likely is: night frights.
For the most part, a bird's night vision is as poor as its daytime vision is acute. It's why both wild and caged birds securely settle-in and perch themselves at dusk, well before it gets dark - they don't want to be caught out in the open when the lights go out.
That said, the fight-or-flight response is deeply embedded in prey animals, and, in the case of defenseless birds, it inevitably means flight. Birds that are frightened out of their sleep will hit the air first and think about it later. In caged birds we call this "night frights," and most of us have been awakened to the panicked thrashing of our domestic flock trying desperately to flee from some imagined threat. Panicked birds will fly full-force into walls, windows, cage walls, wedge themselves behind mirrors and furniture, etc. They can't see the "danger" in the dark, they can't see the rest of their flock in the dark, and all they know is that they're alone and something's chasing them. The only solution is to switch on the lights, let the bird/birds awaken fully, and try to put everyone to bed again. Loads of fun at 2:30 in the morning.
The birds in question, red-winged blackbirds, weigh about 2 1/2 ounces, and can fly from 17 to 28 miles per hour. You can imagine the results when something that light smashes into a building, a telephone pole, a heavy tree branch, or flies into the ground at close to 30 mph - internal bleeding and blunt-force trauma. Whether it was a fireworks display or an hungry raccoon or snake that spooked the flock, it resulted in near simultaneous panic and mass confusion, thousands of birds rising into the air, totally blind, terrified and smashing into each other, and heading off into the darkness at full speed until something solid stopped them forever. I like a good government conspiracy or alien probe story as much as the next guy, but Occam's razor demands that we accept the hypothesis that answers the question with the fewest new assumptions. I'm putting my money on night frights...
More here: 4 and 20 blackbirds, and 4,000, dead in the sky. "Celebratory fireworks likely sent thousands of discombobulated blackbirds into such a tizzy that they crashed into homes, cars and each other before plummeting to their deaths in central Arkansas, scientists say..."
Here's a nice rundown of the black helicopter stuff: Counting Dead Blackbirds: Conspiracy Theories Abound In Arkansas
Worldwide phenomenon! Swedish birds 'scared to death': veterinarian
Update: "I told you so..." Fireworks likely cause of massive Ark. bird kill
Another Update: "I told you so (again). In a thoughtful radio interview, Cornell Lab scientist Kevin McGowan pretty much confirms everything I said above: Radio Interview About Dead Blackbirds