Wednesday, January 05, 2011

Mystery Bird Deaths, on a Massive Scale

New Year's Eve in one Arkansas town was the occasion for a mass die-off of Red-winged Blackbirds – about 5,000 by most accounts. Since then, another 500 blackbirds have died in Louisiana.

Today it emerged that about 500 red-winged blackbirds and starlings had been found dead in Louisiana. Their tiny corpses littered a short stretch of highway near the city of Labarre after apparently falling dead from the sky.

That would be spooky enough. But the Louisiana bird die-off came just a few days after up to 5,000 blackbirds fell to earth in neighbouring Arkansas in the small town of Beebe. Residents there had reported stumbling upon the bodies littering the ground and even being hit by them as they fell. One woman said she was struck while walking a dog. Another avian corpse bounced off a police car.

In even more grim news, anglers and other members of the public reported that more than 80,000 drum fish had suddenly died in the state's Arkansas river, about 100 miles west of Beebe. The silvery bodies of the fish floated in the river and washed up on its sides having died at roughly the same time. In another incident, hundreds of miles away on the Maryland coast of Chesapeake Bay, tens of thousands of dead fish also washed up on the shore.
Local biologists ascribe the deaths in Arkansas to shock, either from a storm or from fireworks.
The birds' deaths, however, are a deeper mystery. Officials were still collecting bodies in Louisiana but have already examined those from the incident in Arkansas.

They concluded that the birds had suffered internal trauma. That could have happened if a single flock had suddenly got caught in a violent and unusual storm. Or, it has been speculated, a local fireworks display could have startled the birds so badly that they were unable to prevent themselves from flying into trees, pylons and houses....

Louisiana's state wildlife veterinarian said yesterday at least some of an estimated 450 birds that died near Baton Rouge may have flown into a power line.

Jim LaCour said that the grackles, starlings, brown-headed cowbirds and red-winged blackbirds had broken beaks and backs.
These are all strange events, even if the explanations turn out to be correct. Mass bird deaths happen and are reported fairly regularly. In most of those cases, though, the reason turns out to be poisoning, through bait left out for other animals. If the Arkansas event was precipitated by the fireworks show, I wonder how many other times fireworks shock birds enough to kill them.