Mocking the Apocalypse, David Letterman Goes For the "Dead Birds Falling From The Sky" Gag Whitney Jefferson · 01/05/11 11:14AM Midway through Dave's monologue, a slew of dead birds fell from the sky. Of course, the birds were fake and likely tossed from above by a lowly Late Show page, but it's nice to see Letterman mock Earth's impending doom.