Trauma as a result of thunder and lightning is being blamed for the death of thousands of blackbirds who rained down out of the Arkansas sky on New Year's Eve.
"There were multiple thunderstorms that night and for several days that week," said Dr. George Badley, state veterinarian for the Arkansas Livestock and Poultry Commission. "Red-winged blackbirds fly in large groups and if they got pulled into a thunderstorm, likely lightning struck them. That would be my best guess."
Officials sent some of the carcasses of the red-winged blackbirds to Badley's Arkansas laboratory. The rest of the birds to be tested were taken to laboratories in Georgia and Wisconsin.
"Almost every one of them ... had multiple internal hemorrhages which would mean that it was trauma, not a disease process. Their stomachs were empty, which would rule out toxicity from eating some kind of poison grain," Badley said.
According to preliminary testing released late today, the trauma was primarily in breast tissue, with blood clots in the body cavity and internal bleeding. All major organs were normal and the birds appeared to be healthy, the tests found.
Blood and culture tests on the birds are still pending.
Officials from the Arkansas Game and Fish Commission said that at least 2,000 carcasses of the birds were collected by the U.S. Environmental Services on Saturday and Sunday, but they believe that up to 5,000 birds actually tumbled from the sky.
It is very unusual for redwing blackbirds to fly after dark, because they have poor night vision.
But Game and Fish Commission officers said there were reports of loud noises shortly before the birds began to fall from the sky, which may have accounted for why they were flying at such an unusual hour.
The black birds roost in huge numbers across eastern Arkansas.
"They're almost like clouds at times the way they fly across the landscape," Jeff Williams from the Arkansas Game and Fish Commission said.
Williams said birds are more susceptible to trauma than many people realize.
"Birds are pretty fragile. They can be stressed out very easily," Williams said.
Williams said that fireworks set off by those celebrating the New Year or thunderstorms could have startled the birds. While State Veterinarian Badley didn't rule out the possibility of fireworks, he thought that it was highly unlikely to be the cause.
It's not the first time birds have dropped from the Arkansas sky. Lightning killed ducks at Hot Springs in 2001 and hail knocked birds from the sky at Stuttgart in 1973 on the day before hunting season.
83,000 Drum Fish Dead Along Arkansas River
A freakish weather week in Arkansas that included tornadoes and heavy thunderstorms ended this weekend with not only the mysterious death of thousands of birds, but also the death of tens of thousands of drum fish.
The Arkansas Game and Fish Commission said today that 83,000 drum fish died in the kill.
Just a 125 miles from Beebe, dead drum fish began floating along a 20 mile stretch of the Arkansas River near a town called Ozark last week.
Officials from the Arkansas Game and Fish Commission said the fish kill and mysterious bird deaths are unrelated.
Some of the fish are being sent to Dr. Andrew Goodwin to test at the University of Arkansas at Pine Bluff's Aquaculture and Fisheries Department. Goodwin said that fish kills are fairly common.
"Every day or two, there's a new fish kill somewhere in the U.S.," Goodwin said.
Goodwin willl test the drum fish for infectious diseases and viruses as well as for parasites. He'll also test for non-infectious diseases.
In the summer, fish kills happen due to oxygen depletion, Goodwin said. In the winter, environmental changes like drastic fluctuations between cold and warm weather can shock fish and kill them, Goodwin said.
Goodwin has not seen the fish yet but thinks environmental influences could have played a big role in their deaths.
"My first impression was given that it's only one species and that it happened very suddenly, it has something to do with a strong environmental influence and probably not anything related to toxins," Goodwin said. "The thing that is likely to impact them is rapid temperature changes, we have had some very cold weather and very warm weather."
Drum fish are not studied often because they are not sold commercially or fished very often, but Goodwin said that simple evolution could be at play with the sudden death of the fish.
"Fish, like other animals, go through boom or bust in the population and that stretch of river had a very strong population of drum fish and when that happens they compete for food and other resources and they may not get everything they need and may not be eating the best food," Goodwin said.
Drum fish eat a variety of things including shell fish.
Goodwin said that it will take at least a week to finish all of the testing on the fish.
The Associated Press contributed to this report.