Friday, July 21, 2017

Stoopid Birds!

I often hear people make comments along the lines of: “Today a bird flew right into my window. Stoopid bird!” or “Stoopid ducks - why are they crossing a busy highway?”

But what’s really stupid - or maybe “silly” or “surprising” or even “horrifying” is the better word - is that we as humans have the expectation that wild birds should figure out our unnatural human world and make accommodations for it. In the last few decades, we seem to reason, wild birds should have evolved an understanding of reflective windows in houses and how dangerous they are. And they certainly should have figured out what a highway is and how to avoid it, even if it is inconveniently located between a prime nesting spot and a desired body of water.

"Barn Swallow," by Linda Tanner CC BY-NC-ND 2.0
In fact, birds make surprising accommodations to our human world and its infringement on their own. In The Bluebird Effect (one of my favorite books!), naturalist and artist Julie Zickefoose writes that in multiple incidents recorded in the U.S. and Japan, barn swallows have figured out how to open the sliding glass doors in big-box stores and warehouses. They identify the motion-activated electric eye unit and hover in front of it until the doors slide open. Then the birds quickly fly in (or out) before the doors close. Successive generations learn the technique from their parents, such that a Home Depot in Maplewood, Minnesota, has had a barn swallow colony return every year to nest inside the store since 2000!

"Put Me Back! House Finch Greets the World,"
by John Flannery CC BY-SA 2.0
And this article and video summarize a recent experiment by Mexican scientists seeking to explain why urban house finches have the odd behavior of stuffing discarded cigarette butts into their nests. The scientists theorize that it’s a pest-control technique: the cigarette butts ward off blood-sucking ticks that otherwise infest their nests. It turns out that nicotine has some anti-parasite properties.

Despite these happy stories, overall our human world is changing the bird world much too fast for the birds to keep up. Bird numbers are declining - alarmingly fast for some species - because we’re clearing their habitat, poisoning the insects they eat and the water they drink, interfering with their migration by putting windmills in their path and lighting up the night sky, and so on. (For more information, see the 2016 State of North America's Birds report.)

Even the clever little house finches haven’t yet caught on that those discarded cigarette butts - one of the world’s greatest sources of environmental pollution, by the way - are causing genetic damage to their chicks by interfering with cell division. But doesn’t that make us humans, the ones who throw out the cigarette butts in the first place, the stoopid ones?

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