Bird Watcher's General Store

“A Cape Cod Destination Icon For 40 Years”

Bird Poop

Dear Bird Folks,

I’m one of those guys who is too lazy to wash his own car. I’d rather let the rain do it for me. Rain does a good job on dirt, dust and pollen, but it never seems to remove old bird droppings. Why is bird poop so hard to wash off?

– Dennis, Kingston, NY


I am lazy, too, Dennis,

I have friends who spend every Sunday out in their driveway with a big sponge, a leaky hose and a bucket filled with water and nasty soap, just to make their cars look shiny…as if anyone else cares. That’s way too much work for me. Don’t get me wrong; I like my car to look at least a little clean, but there is only so much effort I’m willing to put into it. Like you, I depend upon the rain, plus an old towel to wipe off what the rain doesn’t wash away. As for the bird poop on my car, I don’t have an issue with that. Birds wouldn’t dare do that to me. They know which side their bread is buttered on. Oh, how I wish that were true. The birds get me as much as everyone else. Actually, they get me even more because my car is red. According to legend, red cars attract more bird poop and, in an unrelated issue, more speeding tickets. One of those things is actually true. You’ll see.

Let’s begin this lovely conversation with a little biology. Mammals, which I assume most of us are, have two separate methods for getting rid of bodily waste. Liquid waste leaves us via one exit, while solid waste takes a totally different way out. Got that so far? Toxins in the blood are filtered by the kidneys, diluted with water and stored in the bladder. Eventually, the bladder becomes filled to capacity and needs to be emptied (which, in my case, is usually around 3:00 AM). This is not how things work for birds. They also have kidneys for filtering toxins, but they have no bladder or other such liquid storage compartments. Why is that? It makes them look fat. Supermodels need to keep their weight in check in order to fit into those sleek outfits, while birds have an even more important reason…flight. Water weight hinders their flying capabilities. So, instead of liquid, the kidneys turn the toxins into a white pasty form of uric acid. The white paste (basically bird pee) is then combined with solid waste (the dark part) before it all exits the bird in one complete package via a single egress, which is located somewhere in the back. (I try not to look too closely.)

Bird poop is fairly easy to remove when it’s fresh, but not so much after it’s been sitting out in the hot sun for a while. Rain will remove pollen and dust, and even dirt, but there’s a funny thing about uric acid: it’s not very water-soluble. Plain water has little effect on it. To make things worse, the dark part of the poop also contains bits of grit. Where does the grit come from? A bird digests its food with the aid of its gizzard (isn’t that just the best name?), which is a thick muscular part of the stomach. When a bird eats something hard – such as a seed, or a nut or in the case of an owl, a bone-filled mouse – the gizzard grinds up the tough parts. To help the gizzard do its job, the bird will ingest small pieces of sand. Eventually, after helping the gizzard grind mouse bones, the grit will pass through the bird and onto the hood of your car. If you scrub too forcefully, the grit could leave minute scratches in your fancy paint job. Most folks likely won’t notice these faint scratches, but the people who wash their cars every Sunday totally will. What to do? The most recommended item for bird poop removal is something you already have, and I know just where you keep it.

A lot of people are handy with tools and they have well-equipped workshops to prove it. Meanwhile, the rest of us get by with a junk drawer packed with tons of stuff, including three critical items: a Swiss Army knife, duct tape and a can of good old WD-40. Standing for “Water Displacement, 40th formula,” WD-40 was invented in the 1950s to protect Atlas missiles (really) from rust. Since then, we have discovered a trillion other uses for this product, with one of them being bird poop removal from cars and trucks. At first, I was skeptical about this claim. After all, I recently heard something about bleach that wasn’t quite accurate. So, I did a little digging and found out it’s true. Several noted car enthusiasts, auto dealerships and the WD-40 company itself all recommend this product for people who have a problem with poop on their cars…or rust on their Atlas missiles.

If I were a real investigative reporter, I’d conclude this column by discussing a series of bird poop removal experiments performed on my own car using WD-40. Actually, that was my plan all along, but the birds wouldn’t cooperate. For over a week not a single bird pooped on my car, no matter where I parked it. Stupid birds. And my car is red. This is contrary to a study that was done in Britain (of course), which concluded that red cars are most often targeted by birds. Don’t ask me why the birds pick red cars more often, or why the Brits felt it needed to be studied.

I’m with you, Dennis. Let the rain wash your car for you. But when it comes to removing bird poop, you’ll have to dig into your junk drawer for your trusty can of WD-40. As for the speeding ticket thing, red cars actually aren’t ticketed more often. That honor (according to yet another study) belongs to white cars. And there are some drivers who seem to get speeding tickets no matter what color car they drive…just ask my wife.