Are Roadrunners Really Real?

As a father, I believe it is my duty to see to my son’s education. So I’ve been exposing him to the classics. Specifically, Looney Tunes cartoons. I was flabbergasted when one of his friends stated he didn’t know who Bugs Bunny was. I mean, what is this world coming to?

So we’re sitting on the couch, eating popcorn and watching the Coyote blow himself up, and flatten himself, and fall off things in his endless quest to catch the Roadrunner. Dynamite and shotguns and anvils to the face. Good, clean family fun. Right? Right. And while we’re watching, my son asks the question. “Are roadrunners really real?”

“Well, yeah,” I tell him. “They live in the southwest.”

On the screen, the Roadrunner beep-beeps, and sticks his tongue out, and leaves the Coyote eating his dust.

“Are they that fast?” my son asks.

“I doubt it,” I reply. “But, let’s find out.”


He doesn’t think roadrunners are real?

It’s a sensible position, if you think about it. We weren’t watching Wild Kratts or Dinosaur Train or some other sort of educational program. We’re watching cartoons about coyotes getting 100,000 pound weights dropped on them. He’s seen coyotes on TV and at the zoo, so he can trust they’re real. But beeping birds that can outrun trucks? Yeah, he’s got a right to be skeptical.

Point taken. So tell us about roadrunners.

Sure. This is a roadrunner:

Specifically, that is Geococcyx californianus, also known as the Greater Roadrunner, a member of the cuckoo family (or, technically, a member of the Cuculidae family which includes roadrunners, cuckoos, and some other birds). As you can see, they don’t look much like the Roadrunner from the cartoons. They’re also a whole lot smaller than a coyote – coyotes in the American desert southwest range 15 to 25 pounds and get about 4 feet long, while the Greater Roadrunner gets up to 2 feet long and weighs up to 1 1/2 pounds. They’re also not blue and purple. They’re a mottled brown and white that blends in with the scrubland and desert they (mostly) inhabit – they can be found as far east as the Mississippi River, but you mostly find them in the southwestern United States and northern Mexico. Also, unlike the cartoon Roadrunner, they don’t beep. Instead, they make a sound that’d I’d describe as sounding like “wut-wut-wut-wut“.

The cartoons show the Roadrunner stopping to eat piles of birdseed, as part of the Coyote’s traps. If Wiley E. Coyote was hunting a real Greater Roadrunner, he’d be better off with a heap of bugs. Roadunners are primarily carnivorous, eating insects, spiders, scorpions, mice, other birds, lizards, and snakes (even rattlesnakes). They hunt by running up to their prey, grabbing it in their beak, and slamming it repeatedly against the ground until it stops refusing to be eaten. His trap might work on the Lesser Roadrunner (Geococcyx velox), though – they eat seeds. They als also roadkill, so they’d be attracted to the results of the Coyote’s inevitable failure (which could explain why it seems as if the Roadrunner keeps coming back to gloat…).

How fast is a roadrunner?

Fast. They’re fast.

Roadrunners can fly, keep this in mind. They’re just not much good at it. They’ll fly to get up to their nests, when sprinting downhill, and to escape from predators, but they can’t maintain altitude for more than about a minute. They’re much better adapted to running, and can hit speeds in excess of 20 miles per hour – an impressive feat for a tiny bird – fast enough to catch dragonflies and hummingbirds on the wing. They’re even fast enough to prey on rattlesnakes, one of the few animals that can.

That’s pretty fast. Could the Coyote catch one?

The answer to that is a solid “maybe”, because it turns out that coyotes are fast. They’ve been seen to sprint at up to 45 miles per hour, and can run at up to 20 mph over distances of a mile or two. That speed drops to about 10 mph if they’re running over longer distances. I couldn’t find any details on how long a roadrunner can maintain its 20+ mph running speed, but the videos I’ve watched don’t show them slowing down for much of anything. So, like so many things in nature, it comes down to circumstances. In a flat-out race, Coyote would finally be dining on Roadrunner. But the roadrunner would be bobbing and weaving and trying to dodge until the exhausted coyote couldn’t keep sprinting, and then (assuming it isn’t lodged in the coyote’s jaws) keep running.

Huh. Anything else?

Yeah. There’s one cartoon in which, in an effort to catch the Roadrunner, the Coyote dons a “female roadrunner costume”. The Roadrunner is unimpressed, running up with a sign that reads “No thanks, I’ve already got a date,” before beeping and sprinting off. This, it turns out, is actually fairly accurate. Well, except for the crosdressing coyote. See, roadrunners are monogamous. The mated couple breeds in the sring, lays anywhere from 2 to 12 eggs, and take turns incubating the eggs. It’s not all happy domesticity, though. The fledglings will crowd out any late-hatching runts, which are then generally eaten by the parents.

Also, along with pooping and peeing all at once, roadrunners have an extra adaptation to help conserve water. They excrete waste salt through their tear ducts, as a way of conserving water. As a result, they almost never need to drink – all of the fluids they need come from their prey.


Why Do Birds Poop And Pee At The Same Time?

I don’t know if my son was watching a nature program, or if he’d been talking about this at school, or what. All I know is that, as we were walking into the condo one day, he suddenly stops and points. “Look dad! An owl!”

I stare along the side of the building, wondering which of the trees he’s talking about. Or is it perched on a balcony, maybe? “I… don’t see it,” I say.

“It’s right there!” he exclaims, pointing. “Oh, no. It’s a squirrel. Look, dad! A squirrel!”

“I don’t see it,” I tell him. “But my eyes aren’t as good as yours.”

He nods at that. “Dad?”

“Yes, son?”

“Why do birds poop and pee at the same time?”

…that is not what I thought he was going to ask.

Do they poop and pee at the same time?

This seems like the first place to start, because I’m not at all certain they do. I mean, sure. I’ve heard this before. But it wouldn’t be the first time I’ve found that “received wisdom” is wrong and that something I thought was true wasn’t true. However, in this case, it seems that received wisdom is correct.

This is going to be more than I wanted to know, isn’t it?

Hey, you’re the one reading this.

Pretty much all animals produce ammonia (NH3) during digestion. It’s a side effect of the breakdown of proteins, which all animals need whether they’re carnivores or herbivores. Ammonia is, however, toxic (doses of 350 mg/kg of weight can kill), which means that animals have to deal with it in some fashion. And by “deal with” I mean “get rid of”.

Generally speaking, mammals will mix it with some of the waste carbon dioxide (CO2) they produce through breathing and convert it into urea (CO(NH3)2) – a far less toxic chemical (the lethal dose is 8,471 mg/kg) that also happens to be water soluble. Mammals then, generally speaking, expel it (along with other waste chemicals) in the form of urine.

Birds don’t do this. Birds, it seems, don’t even have bladders.

Sigh. Tell me more.

To start with, most birds convert ammonia into uric acid (C5H4N3O3, lethal dose around 5040 mg/kg) instead of urea. The other thing they do, which is the reason why they simultaneously poop and pee, has to do with anatomy. See, bird excretory systems work a lot like lizards. They have kidneys, of course, and ureters (the ducts that allow urine to leave the kidney). However, they lack bladders. Instead, they have something called a cloaca – a multipurpose organ that serves as both the reproductive and excretory organ.

The urine enters the cloaca through the ureters, where it is pushed up into the large intestine. The large intestine re-absorbs much of the water content, allowing the urine to be concentrated into a thick paste before it is passed by the bird. since uric acid dries white, this lends bird droppings their distinctive appearances.

So, in short, birds poop and pee at the same time because of evolution.  And because they aren’t equipped to poop and pee separately.