This is what caused it
USDA found to be poisoning bird populations, causing mass die-offs involving millions of birds (http://www.naturalnews.com/031076_USDA_bird_deaths.html)

Different bird kill.
Posted from my iPhone/Mobile device

Low-scale advanced weaponry testing...

sounds Fishy ! and WHAT poison is not lethal to other animals?

now there is a spray that removes the oil from feathers so they have no resistance (removes waterproof) to temperature or getting hypothermia
but other than that .........i can think of none.

I just love the --Poison the Truro Crows to make room for the Plovers maneuver--- Especially since they wanted to do it during Crow hunting season.