Hmmmm, I seem to recall hearing the bees were on the rebound, but I have nothing to substantiate that claim.
As for the birds (Hitchcock was fantastic, only "scary" movie I've ever seen), I'm willing to bet that the birds were feeding in some contaminated/poisoned source, and that the adverse effects occurred on the same time scale. I've been interested in hearing reports from the biologists for some time now.
--Edit: Scratch that, sorta. Trauma and stuff.--