January 8, 2011 in Nation/World

Aflockalypse not now, expert says

Blackbird specialist offers bird deaths perspective
Amina Khan Los Angeles Times
 
Associated Press photo

A flock of redwing blackbirds flies through a field near Bismarck, N.D.
(Full-size photo)

LOS ANGELES – Roughly 5,000 dead and dying blackbirds fell from the Arkansas sky on New Year’s Eve. That mysterious event was followed by the appearance of about 500 dead birds along a Louisiana highway and additional bird-falls in Kentucky, Sweden and Italy.

The unusual series of macabre avian incidents has many people wondering: Is there something in the air, or is this nothing to get our feathers ruffled over?

Richard Dolbeer spent 36 years studying blackbird interactions with agriculture and aviation for the U.S. Fish and Wildlife Service and the U.S. Department of Agriculture in Sandusky, Ohio, before he retired in 2008. He spoke with the Los Angeles Times to dispel any worries about the so-called aflockalypse.

Q.Is this a sign of the end times?

A.No, it’s sort of par for the course.

We estimate the population of red-winged blackbirds (the variety that fell over Arkansas) is probably around 150 million at the start of the nesting season every year in May.

By July, the population increases to over 300 million blackbirds because all these young are hatched, and that population has to balance itself on an annual cycle. So over the nine-month period between July and the next May, you have 150 million red-winged blackbirds die through various events – being caught by cats, flying into wires, being shot by farmers trying to scare them out of their cornfields, dying of exposure to cold weather, and so on.

Having 5,000 red-winged blackbirds die is a drop in the bucket, so to speak, in terms of the total population that dies every year. Most of these birds are roosting in the countryside, somewhere in marshes in the South, so you could have many of these events occurring and no one would even know.

So this isn’t one of the signs for the fulfillment of the Mayan calendar.

Q.Have there been other such events in the past?

A.One thing comes to mind: About 15 years ago there was a case at Kansas City International Airport where several snow geese fell out of the sky and landed on the airport runway. Just by coincidence, another jet aircraft unrelated to Kansas City’s airport had collided with those geese.

There are a number of cases where birds collide with aircraft and have fallen into people’s backyards or along the highway or whatever. But if you go back to the Arkansas phenomenon, this obviously wasn’t the case.

Q.What about birds-gone-wild events?

A.There have been cases of birds getting drunk and flying into windows after feeding on fermented berries. This has been documented. Again, it’s not a huge number, but you might have small flocks of 20 or 30 robins that do this.

Q.What’s the biggest mass bird event you know of?

A.From an historic point of view, many, many birds were killed back in the 1970s and ’80s in an effort to reduce the population in the South during the winter. They would wait till the birds would roost at night and then they would spray this surfactant mixed with water onto the birds, either by fire hose or irrigation systems in helicopters.

The surfactant is a nontoxic substance – it doesn’t kill the birds directly. But it allows water to soak through the feathers on the bird. Under normal conditions birds have oil coated on their feathers, and this allows birds to shed water off their feathers. You’ve heard the expression “water off a duck’s back”? The water never gets to the skin. But if the conditions were right – and they would typically try to spray the surfactant on nights it was predicted to rain – the birds would get soaking wet and die of hypothermia. Millions of blackbirds and starlings were killed in these roosts between 1974 and 1992.

Q.Did that dent the blackbird population?

A.They’re still there. They have a fairly high reproductive rate, so the population has sustained itself. In a sense we should be very thankful – if we didn’t have 150 million dying every year, we’d be up to our eyeballs in blackbirds.


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