As omens go, dead birds raining from the sky can be seen as pretty predictive of grim times environmentally.

Catastrophic, even. And the seers would have been right. A volcano darkened the skies of Europe. Crude oil spread its foul sheen over the Gulf. Ice caps and glaciers continued to retreat. A tsunami opened up a tide of radiation in Japan.
Plague of frogs? Well, they're still dying off at an alarming rate worldwide. So Earth Day this year, 41 years since the first, seems "double, double, toil and trouble" to many.