5,000 dead red-winged black birds still bewildering

necropsy

Dead Birds at the Arkansas Livestock and Poultry Commission Diagnostic Laboratory in Little Rock, Ark., Monday, Jan. 3, 2011. (AP Photo/Danny Johnston)

The Daily Beast is pronouncing “Case Closed” on the 5,000 red-winged blackbirds that fell on Arkansas–or as every news story likes to put it “rained from the sky.” Their rock solid source is the New York Daily News, which quotes a guy from Cornell who says they might have gotten swooped up in a “washing machine type storm.”

Mass, inexplicable die-offs in the animal world are oddly not that unusual. When they die at the same time, you’ve probably either got a physical event or a mass, acute poisoning. (Not, say, West Nile Virus, to which blackbirds are especially vulnerable.)These birds did show signs of trauma and it turns out that because their night vision is so lousy, they have trouble finding their way at night.

What complicated the mystery was that 100,000 dead drum fish started washing up 125 miles away in Ozark, AR, near Fort Smith, just the day before. Fish and Game officials were quick to say that even though they couldn’t explain the deaths they were positive they weren’t related. Yeah, right. The Salton Sea had a die off of both fish and birds in 1999 and it turned out to be botulism.

The going theories are that the birds were spooked/hit by lighting, hail and/or fireworks. Or as the Daily News puts it: “natural causes.” And now every town with a few dead birds wants to get in on the dead-birds-raining-from-the-sky glory. No thanks, Gilbertsville, KY, and Laberre, LA, get your own freak of nature.

It’s easy to dismiss these weirdo events as just some other inscrutable mystery of the hill country, but sometimes it’s a much bigger deal. In 1984 a staggering 29 then-endangered bald eagles turned up dead at the same time of year in DeGray Lake, AR. (It would form almost a perfect equilateral triangle with the other two sites; it’s not near them.)

The dead eagles (and some sick coots) didn’t have too much pesticides or lead, so everyone was stumped. Then the U.S. Geological Survey figured out they had brain lesions and a disease now called Avian vacuolar myelinopathy (AVM). It kills lots of eagles, coots and other waterbirds (and one owl). They don’t know what causes it, but “natural or man-made toxins are suspected.” Researchers N.J. Thomas, C.U. Meteyer and L. Sileo say that when it is acute, it’s probably from a toxin and that specific chemicals are known to cause similar lesions. (Chemicals as varied as rat poison bromethalin, halogenated salicylanilides (which rid animals of worms, fleas and ticks) a TB drug and certain exotic lilies and Helichrysum plants.

So, each of these cases is worth looking into because sometimes it’s not just a news hole-filling freak show, but a hint that there’s a dangerous chemical around.

Where to See Wildlife Down South

Where to See Odd Birds (that are still alive)


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