I've been holding back on writing anything here about the spate of reports concerning mass bird die-offs in the United States and around the world. Frankly, this story reeks, to me, of the sort of "unexplained phenomenon" that later turns out—with much less fanfare—to have an extremely mundane explanation. It's making headlines now, but I would be surprised if this is important to anyone within a few months (except a few conspiracy theorists, and the publishers of books about ostensibly unexplained phenomena).
Smithsonian Institution bird curator Gary Graves apparently has a similar perspective. He doesn't think these bird deaths are a sign of anything nefarious—or, at least, nothing more nefarious than local people taking it upon themselves to stress out a large roost of "nuisance" birds until it flies away. There's a head count associated with that kind of thing, he says, and it's not particularly odd to see a few thousand birds die this way. But, with roosts numbering in the millions of birds, that's not a large percentage lost. The only thing different in this case, he says, is that the dead birds landed on lawns, rather than in the wilderness.
But what about multiple bird kills happening in various locations? According to Graves, this is one of those times where the human brain's penchant for pattern-finding has gone a little haywire. Mass bird deaths aren't uncommon. There's a lot of reasons why they happen. Once we're primed to pay attention, we start to see them everywhere. But it doesn't mean those incidents are connected—any more than a double homicide in Arkansas is likely to be connected to a double homicide that happens the same week in Louisiana. We could be seeing a pattern, sure. But the chances aren't real high. Remember the large fish kill that happened in Louisiana last summer? Everybody speculated the oil spill was to blame. In reality, it was a natural occurrence, caused by fish getting trapped in low-oxygen tidal pools.
And, honestly, looking at the reported cases, I'm not sure I even see much of a pattern, at all. Let me explain ...
If you look at the Google map Xeni posted earlier today, you'll see that most of the mass animal deaths marked aren't blackbirds. They aren't even mostly birds*. Here are the bird deaths marked:
&bull:Texas, number of birds not given—just "a large number": Texas Park and Wildlife officials say there are always dead birds on this particular bridge, probably because they get spooked by predators and then fly, in a group, into the path of cars.
&bull:Sweden, 50 to 100 jackdaws: No known cause, but experts think the birds were probably weak from overwintering, and, after being startled by fireworks, flew into traffic. Remember, this is 50 or 100 birds out of a flock that would probably have numbered in the hundreds of thousands.
•Kentucky, "dozens" of dead birds: In this case, nobody saw the dead birds except the woman whose yard they landed in. She cleaned them up and, by her own admission, thought nothing of them until reports about the Arkansas die off scared her.
Then, you have the widely reported cases—5000+ in Arkansas and 500+ in Louisiana. And that's it.
The birds aren't all the same species. Other than the Arkansas case, they aren't dying very high numbers, relative to the likely size of the flocks they came from—and Gary Graves isn't even especially concerned about the size of the Arkansas die-off. One of the cases isn't new, but rather something that happens regularly in the place it was reported. Another was pretty much just anecdotal. This doesn't scare me. And it shouldn't scare you.
Have there been incidents where pollution, manufacturing, warfare, or some other scary human activity has caused a mass die-off of animals? Sure. But just because that has happened, it doesn't mean it's any more likely to be happening now. Or any more unlikely, for that matter. This is what I was talking about a couple of days ago with meta-cognition. You can't just look at what's happened before, compare it to current events, and say, "This MUST be it!"
You have to look at the specific situation. And, in this case, once I'd seen the details, and once I'd read a little about the behavior and size of bird flocks, this stories no longer seemed weird, and they no longer seemed linked. I could be wrong. And you're welcome to be smug if it turns out that I am wrong. But I really don't think we have a budding catastrophe, of any sort, on our hands.
Here's what I've learned from a childhood spent reading Time/Life books about "unexplainable" phenomena: A mystery that's only mysterious if you ignore the details isn't much of a mystery.
*We can get into fish kills some other time. The birds are being played as a big deal right now, so I wanted to address that alone.
Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.