A dead bird lies on the ground in Beebe, Arkansas, on Sunday after being thrown off the roof of a home by a worker with United States Environmental Services LLC.
More than 3,000 red-winged blackbirds mysteriously tumbled dead from the Arkansas sky on New Year's Eve, the Arkansas Game and Fish Commission told the Associated Press. (Visit National Geographic's backyard birding central.)
A preliminary report—released Monday by the Arkansas Livestock and Poultry Commission—suggests the birds died of trauma of unknown cause.
"The birds obviously hit something very hard and had hemorrhages," game-and-fish commission bird expert Karen Rowe told CNN.
It's unknown whether the trauma occurred during contact with something in the sky—such as lightning or high-altitude hail—or when the birds hit the ground, Rowe said.
Commission scientists began to examine the carcasses today, and final results on the exact cause of the birds' death could be back within a week.