The official cause of death of the estimated 4,000 to 5,000 red-winged blackbirds found in the town of Beebe, Arkansas on New Year’s Eve is blunt-force trauma, according to the results of three independent laboratory tests that were reviewed and released by the Arkansas Game and Fish Commission (AGFC) yesterday. Severe weather, chemicals and bacteria were all ruled out as causes for the deaths.
The tests were conducted by the Southeastern Cooperative Wildlife Disease Study (SCWDS), the Arkansas Livestock and Poultry Commission and the U.S. Geological Survey’s National Wildlife Health Center in Madison, Wisconsin. The SCWDS report concluded that, "In most instances, such traumatic injuries in wild birds are due to flying into stationary objects such as trees, houses, windows, power lines, towers, etc.”
These findings come as no surprise to Gary Graves, a Smithsonian curator of birds, who predicted a similar conclusion earlier this month. "Well, it's kind of what I expected," Graves said. "There's nothing mysterious in it."
What was interesting to Graves was the size of the birds' roost, which, according to the report, was estimated at 1.6 million birds. "That's huge. So when you look at the number that was actually killed, that's hardly any," Graves said about the 4,000 to 5,000 that died in the incident.
But what caused the birds to fly the coop?
“It appears," the Arkansas Game and Fish Commission concluded, that "unusually loud noises, reported shortly before the birds began to fall, caused the birds to flush from the large roost. Additional New Year’s Eve fireworks in the area may have forced the birds to fly at a lower altitude than normal. Blackbirds have poor night vision and typically do not fly at night.”
According to Graves, we may never know what spooked them, conclusively. "There's a proximate cause and an ultimate cause. The proximate cause was death by blunt force trauma, but what spooked the birds, that hasn't been absolutely determined," Graves said. "And it never will be. You can't go back in time and recreate the event and no one was there recording the event as it happened."
The Arkansas Game and Fish statement reports that radar images determined that the first group of approximately 6,000 to 7,000 birds began their exodus at 10:20 PM. There was another exodus, slightly smaller in number, at 11:21 PM. Gary Graves knows Sidney Gauthreaux, the expert who studied the images, and trusts his findings. "The guy is the world expert on avian radar ornithology," Graves said.
Graves says he still continues to receive correspondence from people speculating about the cause of the bird die-off. "People have sent me some very strange stories and links," Graves said, including one from a women who claims to be from the Constellation Pleiades and knows of a government conspiracy. "It's just preposterous the fantastic things that people believe," Graves said of some of the theories.
And so, it appears, the mystery is solved. There was no conspiracy, and the subsequent bird deaths reported in Louisiana, Canada, New Zealand and Sweden are unrelated.
"They're independent events," Graves said. "The common denominators are big roosts, a lot of birds in a single place and bird behavior, but they aren't connected by some kind of causal thing."
"What astounds me as a scientist is that people want to find some kind of extraordinary cause for the most mundane things," he said. "And one of the bedrock, fundamental foundations of science is parsimony. What that means, often times, is the simplest explanation is the correct one and if you can't disprove the simplest explanation, there's no need to go to a more extraordinary one."